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A I .I I A inmafimmmmllnlt. IIIAII II. “V IIIII~|II..InI! II III II . . .‘(A Ir I. Iadnffilquhv?‘ (IIIIUIII A A IMIt‘ I. .I Ir Iggll UAIIIISIIMIIII liiafiAIIflunIA (In. . IIIIIII... A A I I, UIIIAKHII ..WIuUuVIx :aIurIHhN1\\ ENE} IIIthIIWWIIflIIIIIIIInw IIIJIAI mmuuhl I 391....)in IUIIIHIIIHIHHIIIAIYHmIHIIlIAIlflIIIl. Ir A khuIIIIIIInWquIIIIII‘IIl . InmguA.nn\lAlaylilllIIJil (“LIImNmuqqu‘AufllfiPIllsflnuiiI 114334 41A II I III. III . I A. “IIIIIIIII. .. I .r1.“Na...ouIIIII \InIJI .... II 1.5;ikl1h..ns0«nflnr!&flwiyi!%y .. I . 116.2.“ I IIthuwwIIIIIII I tlIfinulh uHMuAIIIIIIIu IIIIAIIJU “JVJWIIIII; nAlIIA IIIIIIIIII. In [A II I . I AA . . A . IIananIlnl II [IE u I . I IIAIIII 11‘ IIIUIAflIII‘IIIIJII.‘.I.D. .HIIIILIIIIIIMAIAJUHPVAII III .AIIIIIIIIII I ..u‘ WEED. LIBRIER Y : MIIIIIIIII III» , Umver A, .. . «J/ - — '*‘~-“*-~ ~~~ ._ m~.m'~mwa This is to certify that the thesis entitled Hot Weather Livestock Housing Analysis presented by Jose L. Oliveira has been accepted towards fulfillment of the requirements for Ph.D- degree in Ag. Eng. Technology flwéiw Major professor 0-7 639 OVERDUE FINES: 25¢ per day per item RETURNING LIBRARY MATERIALS: Place in book return to remove charge from circulation records /I _ // . .\ /:I."~ ‘- H». '= ABSTRACT rm WEATHER LIVESIOCK musmc ANALYSIS by Jose Lucindio de Oliveira The obj ective of this study was to apply the systems approach to the analysis of hot weather conditions for poultry and swine housing and to develop a simulation model which could be used in the study of parameters affecting the environment . The system was defined as the environment surrounding the black globe thermometer and enclosed by the different segments of the containing struc- ture . A mathematical model was then developed to predict radiant heat load , black globe temperature , Temperature-Hmmidity Index and Black Globe Humidity Index as a function of solar radiation, shade materials, walls, housing dimensions , air velocity, inside and outside air terperature and wet-bulb terperature . Items evaluated by the model included shape factors for the surround sections , radiosity of the surround and relative humidity . Field research was conducted during the summer of 1979 at the Central Fanm Experimental Station in Belize. The environmental data from these field studies were used to verify the model performance. Simulation studies were made using a typical layout of tropical live- stock housing system to evaluate the effects of different structural characteristics on inside environmental conditions . Items investigated included climatic conditions, housing dimensions, and four different roof materials, thatch roof, clay tile, aluminum, and plain and insulated Jose Lucindio de Oliveira galvanized steel. Conclusions from these studies included the following: 1. The Bladk Globe Humidity Index was reduced from. 82 to 80 during the summer in Belize by shielding direct sun radiation into one pen on the west side of the broiler house. 2. The simulation model developed in this study predicted environmental conditions within a 98% range of measured values. 3. The Black Gldbe Humidity Index provided an indicator of comfort which included the significant additional radiant heat load under hot weather conditions. 4. Thatch roofing reduces the radiant heat load per area of animal surface more than plain galvanized steel, clay tile or aluminum. MMJCWI/ L / Approved Maj or Professor WA QAAWMI/ DeMt Chairman To the memory of'my Grandfather Jose Luiz de Oliveira ACKNOWLEDGEMENTS The author wishes to express his appreciation and thanks to the following persons and institutions for the help which made this study possible: To Dr. M. L. Esmay, Committee Chairman, who provided counsel, guidance and encouragement throughout the entire study period and during the investigation and preparation of this dissertation. To Dr. D. Linvill, Dr. M. Abkin, Dr. R. Deans, Dr. H. Person and Dr. A. Rahn who served as members of his guidance committee. To the Agricultural Engineering and Animal Husbandry Departments at Michigan State University, Partners of the Americas, and Belize Livestock Feeds Project for providing financial support and physical facilities used in this research. To the Universidade Federal de Vicosa, PEAS/CAPES from the Ministerio de Educacao e Cultura - Brasil for providing the necessary leave and financial support which made it possible for the author to undertake graduate study. To his officemates Dora Grambau, Art Gold, Fred Hall and Dean Baas for their moral support. To his special friend Sandlin for her advice, encouragement and help which proved invaluable to the completion of this research. To his wife Guainuby and children Tonya, Ricardo and Rinaldo who provided the security of established home and community roles for the frustrations often attendant to the completion of a graduate program. iii TABLE OF CONTENTS ACKNGNIEDGEMENTS. . . . . ....... . ..... . ................. . .......... TABIEOFCON‘I'ENI‘S.......... ..... ............... . .......... LIST OF TABLES ........................... . ..................... LISTOFFIGURES... ..................... ................... CHAPTER 1 INTRODUCTION ..... . ........... . ....... . ........... . ....... 2 REVIEW OF LITERATURE ............ . ......... . .............. 2.1 Introduction ................................... 2.2 Radiation Exchange Between Surfaces ............ 2.3 Radiation Shape Factor ......................... 2.4 The Black Globe Thermometer ............. . ...... 3 MODEL DEVEIOPMEN‘I‘ ............ . ........................... 3.1 General Objectives ........ . .................... 3.2 The Solar Air Temperature Concept .............. 3.3 The Incident Solar Radiation ................... 3.4 Black Globe Thermometer Temperature and Its Surroundings. . ................................. 3.5 Index of Heat Stress or Discomfort Index ....... 3.6 Computer Program Outline ..................... . . iv Page 12 15 18 18 19 20 22 27 28 Chapter 4 EXPERIMENTAL DESIGQ AND PROCEDURES. . ..................... 4.1 Belize's Central Farm Station .................. 4. 2 Construction Characteristics of Swine and Broiler Housings at the Central Farm ........... 4. 3 Experimental Data .......... . ................... 4 . 4 Environmental Modification Versus Feed Conversion for Broilers . . . . .................... 4 . 5 Computation of the Temperature Humidity Index (THI) and Black Globe Humidity Index (BGHI) . . . . 5 NDDELWRIFICATION........... ..... ... .................... 5.1 Determining the Shape Factors of the Surrounding .................................... 5 . 2 The Radiosity of the Surround .................. 5. 3 Validation ..... . ..... . ......................... 5.4 Results and Discussion ................. . ....... 6 SIMULATION STUDIES ....................................... 6.1 Typical layout of Tropical Livestock Housing System ........... . ..... . ....................... 6. 2 Shade Materials Versus Comfort Indices ......... 6. 3 Radiation Studies of Livestock Shades in California. .................................... 7 SUMMARY AND CONCLUSIONS .................................. 7. 1 Summary ...... . ................................. 7. 2 Conclusions ...... . ..... . ..... . ................. 7 . 3 Recommendations for Future Work ................ Page 30 3O 31 32 32 41 52 52 57 58 61 73 73 8O 92 96 96 97 98 REFERENCES. . . ........... . . .............................. 100 APPENDICES. . . ........................ . ................... 103 APPENDIX A . ..... . . . ....... . ........... . ............ 104 APPENDIX B ............. . ......................... . l08 APPENDIX C. . ..... . ..... . ............................ 121 Vi Table 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 LIST OF TABLES Means and standard deviations of environmental parameters for 15 summer days, 1979, from 8:00 a.m. to 4:00 p.m., under three positions in the hog house .................... Means and standard deviations of environmental parameters for 15 summer days, 1979 from 8:00 a.m. to 4:00 p.m. , under the middle position in the farrowing house. ..... Means and standard deviations of environmental parameters for 15 summer days, 1979 from 7:00 a.m. to 5:00 p.m., under two positions in the broiler house .......... Means and standard deviations of environmental parameters for summer trials in broiler house from August 2 to September 26, 1979. . ..... Means and standard deviation of environmental parameters for winter trials in broiler house from January 10 to March 6, 1980. ooooooo Data summary of feed conversion trials in broiler house , Central Farm Station , Belize . Data were reported at two week intervals from August 2 to September 26, 1979, . . ............ Data summary of feed conversion trials in broiler house , Central Farm Station, Belize. Data were reported at two week intervals from January 16 to March 6, 1980 .................. Page ....... 36 ....... 42 ....... 44 ....... 46 .47 Dew-Point temperature , Temperature-Humidity Index, and Black Globe-Humidity Index for 15 summer days , 1979 in the hogs' house. . . . . ........ Dew-Point Temperature , Temperature-Humidity Index .......48 and Black Globe-Humidity Index for 15 summer days , 1979 in the farrowing house ........... Dew-Point Temperature , TeIrperature—Htmudity Index .......49 and Black Globe-Humidity Index for 15 summer days , 1979 in broiler house. . ............ Vii ....... 49 Table 4.11 4.12 5.1. 5.2 6.1 6.2 6.3 Dew-Point Temperature , Temperature-Humidity Index and Black Globe-Humidity Index for summer trials in broiler house from August 2 to September 26, 19 79 ............................ Dew-Point Temperature , Temperature-Humidity Index and Black Globe-Humidity Index for winter trials in broiler house from January 10 to March 26, 1980. . . . . Values for the shape factors used in the verification of the model, for three different types of housing ..... Data summary used to test the modeling, for three types of housing in summer days (1979) , at 170 North Latitude, Central Farm - Belize. .............. . . . Values for the shape factors used in the simulation studies, for two different housing systems ....... Climatic data summary used in the simulation studies to calculate the comfort indices for two different types of housing ...................... Examples of Energy Radiated, Tm and HEHI under shades by various features of the surround , from observations made at El Centro, California ......... viii Page 51 57 60 75 82 94 LIST OF FIGURES Figure Page 2.1 The transfer of heat from.one surface to another by radiation. The diagramlshcws the fate of radiation originating from surface 1 as it is reflected suc— cessively from one surface to the other ............ 10 2.2 Graphic interpretation of View factor after Nusselt (1928). . . . . . . . . ..... . . . . . ........ . 14 3.1 The cross section of a livestock housing showing the segments of the surrounding with respect to a sphere. . . . . 25 4.1 View from.the east side of the eastewest oriented house for growing hogs. ............... . . . . 33 4.2 Perspective ViGW’Of the eastdwest oriented house fOr farrowing ........................ . 34 4.3 View from the west side of the north-south oriented broiler house ........................ . 35 4.4 Structural modification for broiler housing. One pen each on east and west sides of the building was shaded. ...................... . . . 40 5.1 Cross section of the eastewest oriented hog growing house. The gldbe surround was divided into four components. ................... . . . . . . 53 5.2 Cross section of the eastdwest oriented farrowing house. The g10be surround was divided into five components. . .................. . . . . . . 54 5.3 Cross section of the north—south oriented broiler house. The globe surround was divided into five crmponents. ........................ . 55 5.4 Cross section of the northrsouth oriented and.modified broiler house. The glObe surround was divided into three components. ................. . . . . . 59 5.5 Measured and predicted values for THI and BGHI during ijmasnmmem period at the middle position of the east- west oriented hog house ........ . . ...... . . . . 65 Figure 5.6 5.7 5.8 5.9 5.10 5.11 5.12 6.1 6.2 6.3 6.4 6.5 6.6 Page Measured and predicted values for THI and mm during the sumer period at the middle position of the east- west oriented farrowing house ................. 66 Measured and predicted values for THI and mm during the summer period at the east position of the north- south oriented broiler house . ................ 67 Measured and predicted values for THI and KEHI during the summer period at the west position of the north- south oriented broiler house . ................ 68 Measured and predicted values for THI and BGHI for a period from August 2 to September 26, at the east- shaded position of the north-south oriented broiler house ............................. 69 Measured and predicted values for THI and HSHI for a period from August 2 to September 26 , at the east- unshaded position of the north-south oriented broiler house. . ............. . ............. 70 Measured and predicted values for THI and HSHI for a period from August 2 to September 26, at the west- shaded position of the north-south oriented broiler house ........................... . . 71 Measured and predicted values for THI and HSHI for a period from August 2 to September 26, at the west- unshaded position of the north-south oriented broiler house ............................. 72 Layout for type 1 housing . The east—we st oriented swine house ....... . . . . . . . ....... . ....... 76 Layout for type 11 housing. The east-west oriented broiler house ...................... . . . 77 Cros section of type 1 housing. The globe surround was divided into four components . .............. 78 Cross section of type 11 housing. The globe surround was divided into five components. .............. 79 Effect of radiant heat load under uninsulated and insulated galvanized steel roofings, on a hot summer day for type 1 house. . .................... 84 Effect of radiant heat load under a thatch roofing, on a hot summer day for type 1 house .............. 85 Figure 6 . 7 6.8 6.9 6.10 6.11 6.12 Page Effect of radiant heat load under a aluminum roofing, on a hot summer day for type 1 house. ............ 86 Effect of radiant heat load under a clay tile roofing, on a hot summer day for type 1 house. ............ 87 Effect of radiant heat load under uninsulated and insulated galvanized steel roofing, on a hot summer day for type 11 house ..................... 88 Effect of radiant heat load under a thatch roofing, on a hot summer day for type 11 house ............. 89 Effect of radiant heat load under a alum'nmm roofing, on a hot summer day for type 11 house .......... . . . 90 Effect of radiant heat load under a clay tile roofing, on a hot summer day for type 11 house. ............ 91 1 . INTRODUCTIQV Livestock production is becoming more intensive world wide. An animal's environment as defined by Bond et_§l. (1960), is the total of all external conditions that affect its development, response and growth. The external factors that affect the regulation and balance of the animal heat are important. These climatic factors include air temperature, moisture, radiation, light and air velocity, and should be used to define the effective temperature of the environment. Physical environment directly affects production and growth of live- stodk and poultry. Domestic animals are homeothermic. These animals, like human beings, can exist only within a limited range of body temperatures. They must maintain a rather delicate balance between the heat produced within their body and the heat they lose or gain from their environment. The thermo environment surrounding the animal has a direct influence on the amount of heat exchanged. The animal produces heat when transforming Chemical energy frcmtfeed into work. If the heat balance becomes unbal- anced it can reflect directly on growth, production, and health. There- fore, environmental factors are of great importance in livestock and poultry. In.almost every country of the world, livestock production is be- coming increasingly intensive. To increase production efficiently and economically, the buildings which house stoCk should provide the optimum climatic conditions consistent with the needs of the particular livestock. -2- Cold weather is the dominant environmental problem in the northern areas of North America and Europe, while in trOpical countries the critical problem is hot weather. In cold weather conditions the problems are pro- tection of the animals from low temperatures, ventilation to remove water vapor and detrimental gases and to provide enough oxygen. In hot weather regions the problem is With high air temperature, high solar radiation and high humidity. Heat stress is an important factor that limits animals from adhieving their fullest genetic potential in terms of meat, milk, or egg production as well as reproductive efficiency. Prior to detailed consideration of environmental aspects, attention must be paid to certain fundamentals of intensive husbandry that have a profound effect on the whole unit design and the health of the livestock within them, Livestodk production is a challenge in tropical areas where chronic, insidious and complex groups of diseases occur. The challenge presented is one of the most exciting ones found in the long history of livestock production, not the least because the search towards solutions demands the COOperation of agriculturists, architects, engineers, and veterinarians. Alleviation of heat stress by environmental modification would be beneficial in preventing the decline of the livestock production re- sponses. The degree of effectiveness of various environmental modification systems should be evaluated in terms of economical benefit and not neces- sarily in terms of animal comfort. Esmay (1969) states that the heat exchange range between the animal and its surroundings at any time is influenced by the environment. If the effective temperature of the environment is higher or lower than the -3- thermoneutral or comfort zone of the animal , physiological adjustments are required to maintain heat balance. Several indices have been developed and used to predict comfort, or discomfort of the environmental conditions. Generally, the two environ— mental parameters considered have been dry-bulb temperature and humidity. The most common comfort index is the Temperature-Humidity Index (THI) , originally developed by Thom (1958) and since then adopted by the U.S. weather Bureau as a comfort index for humans. During periods of heat stress, an unshaded animal is often exposed to a radiant heat load greater than its metabolic heat production (Bond et_§l,, 1967). THI cannot be effectively employed to predict discomfort and subsequent losses in production and reproduction in livestock animals when the radiant heat load becomes a significant portion of the total heat that the animal must dissipate. It appears that THI would not apply to livestock exposed to high levels of radiant heat load. To create an index integrating dry-bulb temperature, wetrbulb temperature, radiation, and air movement, the Black Globe-Humidity Index, BGHI, was developed by inserting bladk globe temperature in the THI equation in place of the dry-bulb temperature. This research project was directed towards the application of the system approach to the analysis of the environmental conditions in live- stOCk structures during hot weather; The impact of hot.weather on domes— tic animals can be a constraint in efficient livestock production systems, particularly for high producing animals whose nutritional needs have been met. In this study, the level of heat stress that a livestock animal was subjected to from the direct effects of hot weather, was investigated. -4... A mathematical model was developed to predict the black globe temperature and/ or the Black Globe-Humidity Index throughout the day as a function of solar radiation, inside air terperature, type of construction, and orientation of the building. An experiment was conducted during the summer of 1979 at Central Farm Experimental Station in Belize. Heat-stressing environmental con- ditions under different livestock houses were evaluated. These buildings differed in structural characteristics and orientation. The field studies were conducted to verify the model performance . Simulation runs were made using a digital computer to investigate the effects of building modifications that would improve environmental conditions . 2. REVIEWOF LITERATURE 2 . l . Introduction Radiation is a significant portion of the transfer of heat between an animal and its surroundings , particularly in hot weather conditions. A full evaluation of the relationship between animal production and the en- vironment depends greatly on the establishment of quantitative values for the various modes of heat transfer. Heat stress has been defined as any combination of environmental conditions that cause the effective temperature of the environment to be above the temperature range of tie animal ' s thermoneutral zone (Esmay 1969) . When the effective temperature of the environment is higher than the thermoneutral zone of a horeothermic animal physiological adjust- ments are required in the attempt to maintain a heat balance. Consequent- ly the animal's productivity processes diminish. There have been attempts to formulate the thermal components of an environment into a single nurerical index which would reflect the level of heat stress on animals. Generally the indices developed and used to pre- dict the comfort, or discomfort , of environmental conditions considered only the dry and wet bulb temperatures. The most cormon comfort index is the Terperature-Humidity-Index (THI) , originally develOped by Thom ( 1958) and since then adopted by the U.S. Weather Bureau as a comfort index for humans : THI = Tdb + .36 po + 41.2 [2.1] where T db = dry-bulb temperature , 0C T dp = dew point terperature , cDC Berry et al. (1964) reported that the milk production decline of Hol- stein dairy cows was functionally related to temperature humidity index (THI) equation , i. -1.075 - 1.736 NL + 0.02474 (NL) (THI) [2.2] i i absolute decline in milk production , Kg/day/ cow NL = normal level of production, Kg/day/ccw Cargill and Stewart (1966) , verified that the same psychrometric factors that indicate thermal discomfort in humans also reflect discomfort in dairy cows which resulted in decreased milk production . They reported that production at a THI of 76 to 77 declined by one standard deviation from normal level of milk production at which the cows were not in heat stress . They suggested that the ideal design of environment controlled summer shelter for dairy cows could be based on a limiting discomfort index of 75 . Johnson et a1. (1963) reported that declines in milk production were strongly link- ed to THI increases. With a THI of 70 or less, dairy cows experience little, if any, thermal discomfort. However, when the THI was 75 or higher, milk yield and feed intake were seriously depressed . An unshaded cow may be exposed to a radiant heat load greater than its metabolic heat production, thus, reavy stress results (Bond _e_t §_l_. , 1967) . THE does not reflect radiant heat load thus, cannot be effectively erployed to predict discomfort and subsequent production losses under these condi— -7- tions. An index, known as the Black Globe Humidity Index (BGHI) , that indicates dry—bulb temperature , wet-bulbltemperature , net radiation , and air movement , was developed by including the black globe terperature in the THI equation in lieu of the dry-bulb temperature (Buffington et al. , 1977a) . As documented in several studies and reported by Buf f ington , the BGHI was a more accurate indicator of heat stress severity, when incident solar radiation and/or air moverent were high. Under conditions of little or moderate heat stress the BGHI and THI are generally equal . Buffington et a1. (1979) , reported that no significant difference, at the 95% probability level , existed between the THI index in shade and in no shade locations because the dry-bulb or dewpoint temperatures were similar in both locations. The BQiI was found to be significantly higher at the 95% probability level in the no shade location as corpared to the shade condition . No significant differences developed between the THI and BGiI indices at various shade locations, because there was little difference between dry-bulb and black globe temperatures . Yaglcw and Minard (1957) studied several indices in an attempt to relate human and environmental conditions in the British Armed Forces . They developed the Wet-Bulb Globe Temperature Index (WBGT) which related the temperature of a standard black globe thermometer , Tg; the shaded dry-bulb terperature , Ta; and the terperature of a wet-bulb thermometer , T wb . The WBGT index consisted of a simple weighted of the three temperatures WBGT=.7wa+.2Tg+.1Ta [2.3] The WBGT proved of value in describing critical condition in order to reduce heat casualities in army training operations. The success of the WEST was due in part to its simplicity which encouraged its use and im- proved its reliability. Livestock housing design for tropical areas must consider the radiation effect, so that conditions can be ameliorated with the use of environ- mental modifications. ‘Ihe first step in design under hot weather conditions is to prevent solar radiation from striking the animals by proper shading . The next sections present theoretical analysis for determining the amount of solar radiation within the livestock structure. 2 . 2 . Radiation Exchange between Surfaces Thermal radiation is defined as being in the electromagnetic radiation spectrum from the visible range of wavelengths (.4 -.8pm) to the much longer 100unwavelength, (Holman, 1976). The rate of emission of energy from a sur- face is proportional to the fourth power of the absolute tetperature . The Stefan-Boltzmann Equation is: Eb = 0T4 [2.4] where Eb is the rate of radiation heat transfer W/ sq.m o is the Stefan-Boltzmann constant 5.67 . 10-8 W/sq.m.OK4 T is the absolute tetperature C)K The rate of radiation also depends on the nature of the surface as com- pared to a perfect black body. The ratio of the actual emission of heat to the emission of a perfect black body at the same terperature is called the emittance, 8, thus: E: 8 0T4 [2.5] where E is the rate of radiation heat transfer W/hr-sq.m. e is the emissivity of a surface When radiant energy falls on a surface it may not all be absorbed. The proportion absorbed is called the absorptance of the surface. A black body will absorb all the radiation (absorptance = 1. 0) while other surfaces ab- sorb sore and reflect the rerainder. The reflectance of a surface is the prOportion of the incident radiation not absorbed . The equations for radiation heat exchange between surfaces can be de- rived from Equation [2.5] . The simplest case is that of two parallel sur- faces of infinite size. Surface 1 radiates heat at a rate 81 0 Ti. When this radiation reaches surface 2 the proportion absorbed is 52 , so the heat transfer from 1 to 2 is 82 x 81 0 Ti. In the same way the heat trans- fer from 2 to l is 81 x 82 x oTi. Thus, it might be supposed that the net radiation exchange would be the difference between tlese two. 4 _ 4 _ — El 82 0' (T1 T2). [2.6] Q1—2 where Q1-2 is the net heat exchange between surfaces 1 and 2 W/hr—sq.m. 81 is the emissivity of surface 1 82 is the emissivity of surface 2 T1 is the absolute terperature of surface 1 T is the absolute temperature of surface 2 2 This equation is often quoted and applied, but it describes only the first passage between the two surfaces in each direction. In other cases it is incorrect because the radiation which is not absorbed at the first passage is reflected back to the original surface , where sore is absorbed and the remainder again reflected. The quantities involved in successive -10- reflections are indicated in Figure 2.1 for radiation originating from sur- face 1. ]. 2 L\ e O- 4 “1311 \K \ 4 £1 £2 0 T1 Absorbed l\s 8 (1-5 )(1-e )o T4 // 1 2 1 2 1 4 .’/'//)2elT1 Absorbed Pr” «HQ “’82 \(T\2\ ‘31) (1~\2\ 82) elm\\ 2 2 4 l/El 87- (1-61) (1-62) 0'31 4 Absorbed T1, 81 T2182 Figure 2.1. The transfer of heat from one surface to another by radi- ation. The diagram shows the fate of radiation origina- ting from surface 1 as it is reflected successively from one surface to the other. At each collision with surface 2 the proportion absorbed is 2:2. The total transfer from 1 to 2 takes the form of a series describing the successive reflections . 01-2 = 61 82 o T: (l + (1—81) (l—ez) + (l-e:l)2(l-'e:2)2 + ), [2.7] Now the series, 1 + x +x2 +x3 + equals 1/(l—x), so this equation can be expressed more simply: . 4 01-2 = 61 62 o Tl/(l—(l-el) (112)) [2.8] .11. Radiation originating from surface 2 behaves in the same way , and the net radiation is the difference between the transfer from 1 to 2 and from 2 to 1. Q = e x e x o (T? - T:)/(l-(1-el) (1— 52)) [2.9] 1 2 In the case of definite size in a relatively large enclosure, the heat transfer by radiation does not follow Equation [2.9] . This is because rad— iation passing from the object to the enclosure and being reflected there does not all return to the object. Much of it will miss and strike another part of the enclosure (Kerslake, 1972). The long wave radiation heat ex- change between the surfaces of a body and an enclosure may be calculated by a modified Stefan-Boltzmann Equation derived by Christiansen (Monteith, 1973) . - -1 4 4 — oAl[l/ el + (1/ 82 - 1) Al/Az] [Tl - T2] [2.10] where Al and A2 are the surface areas of the enclosed body and the surround- ing surfaces respectively. Equation [2.10] can be used as an approximation for the radiation heat exchange between any body and any enclosure . Christ- iansen points out that its use should be restricted to cases in which tie distance between the surfaces does not vary much from place to place and at least one of the surfaces reflects diffusely. It is remarkable that in the case of a very large enclosure (A2>>A1) Equation [2.10] approaches: 0 (T4 - T2 l 2) [2.11] Q1—2 = 81 All these equations for heat exchange by radiation contain the term 4 1 the emittances of the surfaces. It is convenient to refer to this quantity (T - T3) , which is multiplied in each case by a quantity which depends on as an emittance factor, Fe' Equation [2.11] then is: 4 2) [2.12] _ 4__ Q1-2 ‘ Fe 0”1 T -12— 2.3. Radiation Shape Factor A general expression for the energy exchange between two black surfaces A1 and A2, when maintained at different temperatures becotes essentially one of determining the amount of energy which leaves one surface and reaches the other. To solve this problem the radiation shape factors are defined as: Fl-2 = fraction of energy leaving surface 1 which reaches surface 2 F2-1 = fraction of energy leaving surface 2 which reaches surface 1 F = fraction of energy leaving surface m which reaches surface n Other names for the radiation shape factor are View factor, angle factor, and configuration factor. The energy leaving surface 1 and arriv- ing at surface 2 is: Eb1 A1 F1-2 and that energy leaving surface 2 and arriving at surface 1 is Eb2 A2 F2—1 Since the surfaces are black, all the incident radiation will be absorbed, and the net energy exchange is: Ebl A1 F1-2 ‘ Eb2 E2 F2-1 = Q1-2 [2°13] The net heat exchange is therefore: Q1-2 = A1F1—2(Eb1 ' Eb2) = A2F2-1(Eb1 ' Eb2) [2'14] ..13— The problem now is to determine the value of F or F The follcme 1—2 2-1' ing Figure 2.2 is a graphic interpretation of the shape factor, first presented by Nusselt that leads intuitively to the mathematical express— ions of Reifsnyder (1967). Consider a small plane source of radiation, dAl, radiating to a distant surface of area, A2, containing small differential area, dAZ’ Figure 2.2. The View factor or shape factor can be expressed mathematically by: cos 91 dWl A2 m [2.15] dB is the portion of the total radiation in the small solid angle, dW. A solid angle, measured in dimensionless steradians, is defined as the ratio of the area on a circumscribed sphere of radius r intercepted by the cone starting from the center of the sphere and outlining the area, to the square of the radius, W = A/r2. A complete sphere contains 4m stera- dians. E is the total radiation emitted fromlthe plane source Al' 41 and @2 are the angles formed by the radius joining the differ— ential areas, dAl and dAZ’ respectively. The apparent area of dA2 as seen from dA1 is the projected area of dA2 on the enclosing hemisphere, dAé = dA2cos 4?. But, by Lambert's cosine law, the radiation must be multiplied by the cosine of @1. Thus the amount received by dAfi is proportional to I cos dldA2. It can be seen that this is the area of dAé hemisphere, or ". The shape factor is the ratio of this area to total projected on the base of the projected area of the hemisphere, i.e., the area of the circular base an1+ A2 = f ———2- = 2 [2.16] integrating over the entire surface of A2. Substituting back our expression for dA; and dAé F f cos $1 cos @2 dA2 [2.17] + = dA1 ‘A2 m r2 A2 If the view factor of one finite surface from another is desired, the integration.must be performed overA1 as well, thus F + _ cos oidAl cos cbsz2 [2.18] Al 1"?"er m2 Figure 2.2. Graphic interpretation of view factor after Nusselt (1928). It can be readily seen that the development of the expression for FA2 would lead to the same result. Integration of these equations for specific --———1 -15- cases is quite tedious . Shape factors for regular and georetrically simple cases have been determined exactly by McAdams (1954) and others, and have presented results in graphical or tabular form. To estimate the amount of radiation intercepted by the surface of an animal or plant, the horizontal irradiance must be multiplied by a shape factor depending on the geotetry of the surface and the directional proper- ties of the radiation. To make analysis more manageable , obj ects like spheres or cylinders with a relatively simple geometry are often used to represent the more irregular shapes of plants and animals (Montheith, 1973) . To cotpute the radiant heat load falling on a sphere I not only Shape factors are necessary, but also the rate of emission of energy, radiosity, by the various sections of the surround. The relation between the microclimate and the radiosity of various materials and soils was studied by Bond and Kelly (1968) . Three building materials with different thermal radiation characteristics where chosen: unpainted plywood , white-painted plywood, and embossed aluminum. The radi- ant heat load and radiosity near the walls were measured by using the black globe thermometers and directional radicmeters . Corputations for determining the radiation heat load under a given shade or open housing system are relatively simple after suitable values for the radiosity from the various elerents of the surround have been determined . The steps followed were: (1) determine location of shadow with respect to shade; (2) determine shape factor of each part of the surround with respect to the sphere; (3) multiply the shape factors by the respective radiosities; (4) add the parts to obtain the total radiant heat load. 2 . 4 . The Black Globe Thenroreter Vernon (1932) showed that the mean radiant temperature of the environ- _l6_ ment could be measured by means of a globe thermometer. It consists of a hollow 150mm copper sphere, coated with matt black paint, with a terpera— ture sensing element at the center. The globe reaches thermal (equilibrium when the heat gain by radiation equals the heat loss by convection . Bedford and Warner (1934) found that the globe terperature was correlated with sensations of warmth, and appeared to provide a direct indication of sensible heat stress for human subjects. The globe thermo- meter indicates a combined effects of radiant energy, air temperature, and air velocity; three critical environmental factors that affect human and animal comfort. Bond and Kelly (1955) , in the animal environment research project at Davis, studied the physical characteristics of the black globe thermo- meter, tOgether with some aspects of its practical application in labora- tory and field studies in agricultural research . They described advantages and limitations to further an understanding of its possibilities as an experimental tool. In a study of the effect of ground covers on animal environment, four black globe thermometers were used at four locations to determine the mean radiant temperature (MRI') of the areas surrounding an animal. Globe terperature under shades over a pasture field and over a plowed field, and unshaded in the same two fields provided values for mean radiant terperatures that were indicative of the animal-comfort levels existing at each of the four locations. 'Ihese instruments indicated rot only the srperiority of surrounding grass to dirt (MRT over grass was 7°C less at 12:00 noon), but also showed that a simple shade over either field reduced the MK? by as much as 39°C. Raber and Hutchinson (1950) suggested that the use of a sphere as a reference surface simplifies calculation of the mean radiant temperature -17- and radiant heat load. They pointed out that the numerical heat load for the sphere is different from that for a standing person, because the projected areas on each surface in the surroundings is not the same. This observation of course, is also true for animals . However, for design purpose, sufficient accuracy can be obtained by evaluating the mean radiant temperature on a small sphere located at a point representing the position of the animal. -18- 3 . MOIIIL DEVELOPMENT 3.1 General Objectives The objective of this research was to formulate a predictive mathe— matical model for estimating bladk globe temperature and radiant heat load for animals under various artificial shades and open housing under hot weather conditions. A mathematical model was developed to simulate the radiant heat load, black globe temperature, and bladk globe humidity index as a function of solar radiation, shade materials, walls, eve height, floor type, air velocity, inside and outside air temperature, and dewpoint temperature. Shades may be defined as thermal radiation shields because they can change the radiation load on an animal, but not necessarily affect air temperature or humidity (Esmay, 1979). Most of the livestock housing in hot climates are not simply shades. The housing systems for broilers, laying hens and swine often provide walls and concrete floors. They are not completely closed, but.may have half walls. Thus, the structure not only changes the radiation balance of an animal, but also may affect air velocity, temperature and humidity. The analysis of the environment with respect to a livestock struc- ture in tropical conditions, will be based upon the thermal characteristics of the different parts of the building and surroundings. A simulation model to generate typical weather data for purposes of predicting solar heat -19- gains through building walls and roofs under hot weather conditions is critical. 3.2 The Sol-Air Temperature Concept A convenient index for evaluating the combined effects of solar radiation, ambient air temperature, wind velocity, and surface charac- teristics is the sol-air temperature. Sol-air temperature is a hypo- thetical temperature that represents the effect of ambient air temperature and solar radiation for the analysis of heat transfer through a roof. As proposed by mackey and.Wright (1944), sol-air temperature is _ b I te — to + fc [3.1] where t is the sol—air temperature °C t is the dry bulb temperature °C b is the solar absorptivity of the surface I is the intensity of solar radiation W /sq.mL fC is the film coefficient of heat transfer W /sq.m, °C Solar absorptivity, solar radiation intensity and film coefficient values must be known or assumed in order to compute the sol-air tempera- ture for any environmental condition. .Mackey anderight (1946) developed a method.of evaluating transient heat flow in homogeneous walls or roofs whiCh they extended to cover nonrhomogeneous construction. This method predicts the interior surface temperature as .606 (t.e - ti) .856 +KL, t =t.+ s 1 [3.2] -20- where t is the terperature of the inside surface of the building material, °C t. is the temperature of the inside air, °C L is the thickness of the material, meter K is the thermal conductivity of the material W/ m °C t is the sol-air temperature, °C 3.3 The Incident Solar Radiation The potential of solar radiation reaching a roof surface, can be calculated by using clear day radiation values. Both direct and diffuse solar energy values were obtained from the weather generation model. The total stortwave radiation, I, reaching a terrestrial surface is the sum of the direct normal solar radiation, I dn’ and diffuse sky radia- tion, I The intensity of the direct component is the product of the d. direct rormal radiation, and the cosine of the angle of incidence, Idn; K, between the incoming solar rays and a line normal to the surface. The total intensity of solar radiation I, is: I = I K + I [3.3] where I is the total incident solar energy W/sq m I dn is the direct normal insolation W/sq m I d is the diffuse solar insolation W/sq m K is the cosine of the angle of incidence The angle of incidence will be calculated by using an equation derived in the ASHRAE Handbook of Flmdamentals (1977) . The incident of angle is a function of the solar angle and the orientation angle of the roof. -21- K = COS (BETA) X (IJS (GAMA) x SIN (SGMA) + SIN [3.4] (BETA) X (IDS (SGMA) where BEI‘A = solar altitude angle SGMA = angle of tilt on roof GAMA = PSIZ + SIC where PSIZ = solar azimuth angle SIC = angle or orientation of roof from south The solar angles will be generated on an hourly basis from the weather model . Weather Generating Nbdel SIN (BETA) = C(B (L) C(B (GAMMA) COS (H) + SIN (L) [3.5] SIN (GAMA) where L = latitude of location (radian) H = the sun's hour angle (equal 15 times number of hours from solar moon SIN (PSIZ) + C(B (GAMA) SIN (H)/CDS (BETA) [3.6] I = A x exp (—B/SIN (BETA) [3.7] dn where A = apparent solar radiation at an air mass of zero B = atmospheric extinction coefficient The value of BETA is directly computable by use of the earth-sun equation [3.5] . The value of A in the equation [3.7] varies from around 1230 W/m2 in January to 1085 W/m2 in July, corresponding to respective monthly change in the dust and water vapor content of the atmosphere. Table 1, ASHRAE Handbook of Fundamentals (1977) , page 26.2, provides specific values for B and A for the twenty-first day of each month. (1 - cos (SGMA) F = [3.8] $9 2 -22- where FS = the shape factor whidh relates rectangular surfaces g at an angle to each other ss sg where FSS = the angle factor from.the surface to the sky Id = C Idn Fss [3.10] where C = a dimensionless value taken from.the right hand column of Table 1, page 26.2, Handbook of Funda- mentals, 1977 Id = the diffuse solar radiation from a clear sky that falls on any surface The above equations and data incorporated into a computer program generate the solar insolationlon a surface at any north latitude and building orientation. ‘Values for the solar constant used in the develop- ment of the model, based on the twenty-first day of eaCh month were inter- polated by using a computer subprogram. This interpolation process permits the calculation of the solar radiation for any specific day of the year. 3.4 Black Globe Thermometer Temperature and its Surroundings under steady state conditions, heat gmur1 or loss by radiation to or from a globe must exactly equal that lost or gained by convection. The convection and radiation exchanges can be expressed by qC = 13.53 v (tg - ta) [3.11] qr = so (T: - T: ) [3.12] where q is the convective heat exchange WVSq.mu is the radiation heat exchange WV sq.mn -23- t is the black 91Obe temperature, °C t is the air temperature, °C t is the mean radiant temperature °C v is the air velocity in.meters per second 8 is the emissivity of the globe surface, .95 o is the StefaneBoltzman constant, 5.67 10-8‘W/sq.m. °K t-3 II t + 273 °K 9 a II t + 273 °K 8 Since the heat exdhanged by convection is equal to the heat exchanged by radiation equations [3.11] and [3.12] may be equated as 8 T 4 T = 100 [2.51 x 10 v (t - t) + 111/4 [3.13] S 9 a 100 T4 —— 8 - — TS — 100 [2.51 x 10 v (tg ta 273) +FJ—g—ll/4 [3.14] If the equivalent steady state temperatures of the surround are called mean radiant temperature, Ts’ then the radiation emitted by eadh part of the surround to the globe is the radiant heat load, RHL. The RHL3” T: F. [3.16] i=1 1 -26- where T. is the absolute temperature of each surface of the surround °K F. is the shape factor of each surface of the surround with respect to the sphere n is the number of parts of the surround Then, the mean radiant temperature, Ts’ could be expressed as: 1/4 RHL TS = (T) [3.17] Since the mean radiant temperature was defined by using equation [3.17], the blaCk globe temperature can be found from equation [3.14]. The dependence of radiant heat transfer on the differences between the fourth powers of the absolute temperatures of the surfaces, raised some algebraic corpli cations when heat exchange by radiation was combined with exchange by convection, since the latter depended on the difference be- tween the first powers of the temperatures. The bladk globe temperature, Tg, in equation [3.14] is raised to the first and fourth powers. To solve this equation for Tg a numerical proceed- ure is needed, If the mean radiant temperature is defined and a value is assumed for air velocity, the Zero-Finding Search Routine - ZEROIN may be used to find the blaCk globe temperature. This subroutine ZEROIN, is a highly sophisticated zero finding technique formulated by Lerew in 1975. The subtle algorithm combines the virtues of a guaranteed convergence on all functions and a supra linear convergence on most functions. The computer technique may be used for a Psychrometric Chart as it permits finding all properties from a given dry-bulb and any other property. Also in this model the subprogram was used to evaluate relative humidity and/or dewpoint temperature as necessary to calculate the Temperature Humidity Index (THI) or Black Globe Humidity Index (BGHI). -27- 3.5 Index of Heat Stress or Discomfort Index A.general index is presented for the comparison of environmental stresses on animals. If the index of heat stress covers a wide range of conditions, differences between subjects will be important. .A sub- stantial loss of accuracy occurs unless the index is restricted so that it applies only to certain categories of subjects. Differences in animal heat tolerance can readily be examined in such a restricted range of conditions. Production level, age, and body size can affect an individual animal's ability to tolerate heat (Bianca, 1965). Zones of thermoneutrality, in.which the heat balance of the animal were maintained with.minimal chemical or physical adjustment by the animal, have been established to reflect some of these effects by Biana (1970). The exact combination of environmental conditions at which heat stress begins is difficult to specify for particular species on the basis of breed, sex, age, weight and previous climatic exposure. One of the critical sources of external heat for animals in hot climates is solar radiation. The Temperature Humidity Index, THI,:makes no allowance for additional heat of solar radiation. The THI, as accepted by the U.S. weather Bureau, has however, been adopted by some animal scientiests and.environmental engineers (Thoma, 1958). A Black Globe Humidity Index, BGHI, has been formulated as: Ben: = t + .36 t + 41.2 [3.18] g dp where BGHI is the black globe humidity index tg is the black globe temperature °C tdp is the dewpoint temperature °C r28- Tb include the affect of solar radiation the mathematical model can then provide the black globe terperature and dewpoint temperature needed for the BGHI. The level of comfort or discomfort for different animals as measured by physiological responses, growth, production, health, and/or feed efficiency may be reflected by the BGTI. This mathematical model provides the means of analytically evalua- ting the mean radiant terperature or black globe temperature as a function of solar radiation, orientation of the building, construction materials, and various structural design dimensions. Also, the model can be used to predict the index of comfort or discomfort of environmental conditions from the Temperature Humidity Index, THI, and/or the Black Globe Humidity Index, BGHI . 3.6 Computer Program Outline The model was programmed in FORTRAN IV language for operation on the Control Data Corporation model 6500 oimputer at the Dhchigan State University Computer Center. A complete listing of the model program as used in fine simulations is contained in Appendix A and a brief de- scription follow. The program first accepts data values for latitude of location, angle of roof orientation from the south, and angle of the roof slope from horizontal. A control loop steps the program through the hours of the day from 7 a.m. to 6 p.m. The program generates the sun hour angle, solar altitude, solar azimuth, and the angle of incidence for any specific hour of the day. Subroutine SRINTR, called from the interpo— lation routine, determines the extraterrestrial solar radiation, de- clination, apparent solar radiation at air mass zero, atmospheric extinc- -29- tion coefficient, and diffuse radiation factor based.on the twenty- first day of each month. Another control loop shifts the program through the 30-31 days of the month. The first major execution section of the program.generates direct normal solar radiation, diffuse radiation, and total solar radiation for the 12 one-hour time interval during the day. The day-hour and the generated data for total solar radiation are printed out on the line printer. TWo arrays of outside and inside air temperature are then generated for use in determination of the sol-air temperature and roof temperature. These values for outside and inside air temperature, roof temperatures, as well as wet-bulb temperature are used to calculate radiant heat load, Temperature Humidity Index, and Black Globe Humidity Index. Once the environmental conditions for a particular period of the year - months , day, hours - are determined, the program enters the control loop which steps it through the 12 hours of the day. .At the completion of the computation of a 12 hour day, hours, solar radiation, sol-air temperature, roof temperature, radiant heat load,:mean radiant temperature, globe temperature, temperature humidity index, and bladk globe humidity index were printed.- The process is repeated until the completion of the specified period of the year. -30- 4. EXPERIMENTAL DESIGN AND PROCEDURES 4.1 Belize's Central Farm Station Ebcperimental studies were conducted at Central Farm Research Station, Cayo District, Belize. Belize is situated on the eastern seaboard of Central America between latitudes 15° 53' N and 18° 30' N. The country is bounded on the south and west by the Republic of Guatemala and in the north by the Republic of Mexico. During the past three years, poultry and swine experimental feed trials have been conducted at the Central Farm as part of the Belize Livestock Feeds Project. This project was based upon an agreement between the Belizan Ministry of Agriculture and Land, Heifers Project International and the Animal Husbandry Department, Michigan State University . Previous research study done by Costa (1979) in the field of animal nutrition stressed the need to study further the effect of environ- mental factors on feed intake and production. Belize field studies indi~ cated that the position the animals were confined in the house affected feed intake and growth. The main purpose of the Belize field research was to investigate any possible relation between climatic factors and animal production ef- ficiency and verify the model. The effect of specific shelter modifications on weight gain and feed conversion was measured. -31. 4. 2 Construction Characteristics of Swine and Broiler Housing at the Central Farm 1. Feed Project and Experimental Hog Pens An experimental hog growing house was oriented east and west and had the following characteristics; zinc galvanized metal gable roof at an angle of 16° from the horizontal, 1.2 m high wood slat walls, and a con— crete floor. The building dimensions were 8 x 17 x 2.3 m. Environmental measurements were taken at east, middle, and west central positions in the building at 0.5 m above the floor (Fig. 4.1) . 2. Farrowing House An east—west oriented f arrowing house had the following character- istics; zinc galvanized metal gable roof at an angle of 15° from the horizontal, l. 30 m height concrete block walls , and concrete floor. The building dimensions were 8 x 20 x 2.3 m. Environmental measurements were taken at a central position in the building 0.5 m above the floor (Fig 4.2) . 3. Broiler House A north-south oriented broiler house had the following characteris- tics; thatched gable roof at an angle of 44° from the horizontal, screen wire walls, and a white marl stone floor. The building dimensions were 7.5 x 22 x 2.4 m. It consisted of 20 2.6 x 20 m pens, 10 on each side, separated by a 2 . O m central corridor. Environmental measurements were made in one pen on the east side and one on the west side of the house at 0.30 m above the floor (Fig 4.3) . The environmental factors measured were; ambient air temperature, black globe temperature , wet-bulb temperature, and air velocity. Environ- mental measurerents in the poultry and swine buildings were taken from -32— 7:00 a.m. to 5:00 p.m., at two-hour intervals from July 6 to July 22, 1979. The air and black globe temperatures were measured with copper-constantan thermocouples . The wet-bulb temperature was measured with a sling- psychrometer, and the air velocity was measured with a mechanical anemo- meter . 4. 3 Experimental Data A total of six different measurements were taken for 15 summer days in three buildings. These buildings differed in structural characteris- tics and orientation. Figures 4.1 and 4.2 show the east-west oriented hourse for growing hogs and farrowing, respectively. Figure 4. 3 shows the north-south oriented broiler house. All measurements of the environ- mental factors have been tabulated (Appendix B) . A summary of the means and standard deviations for the environmental parameters , for each type of building, is presented in Tables 4.1, 4.2, and 4.3. 4 . 4 Environmental Modification versus Feed Conversion for Broilers Environmental data (see Table 4. 8) provided information about dif- ferent microclimatic conditions in the broiler house throughout the day. The difference between the inside air temperatures and the black globe temperatures reflect the additional effect of solar radiation on an animal. Structural modifications were made on one pen each on the east and west sides of the broiler building to shield direct solar radiation from inside of the structure. The shades consisted of thatch material supported in lateral positions along the outside walls. Figure 4.4 provides a sketch of the structural modifications for the broiler building. -33_ .mmo manage How 850: ooucomuo umoslummo 05 mo moon ammo ofi ERG~ 33” H6 899m -34_ “a. Jm;:9.a.q. a”... . . . m . -35- Figure 4.3 View from the west side of the north-south oriented broiler house. Table 4. 1 Means and standard deviations of environmental parameters for 15 summer days, 1979, from 8:00 a.m. to 4:00 p.m., Lmder three positions in the fog house. Parameters Units Daytime Hours Position 8.0 10.0 12.0 14.0 16.0 East Side Inside Air Temperature 0C 29.1 31.0 32.1 30.6 32.0 Standard Deviation : .99 il.6 : .94 i1.8 :i.6 Black Globe Temperature 0C 33.6 33.0 33.6 32.0 32.2 Standard Deviation i3. 7 i1. 7 10.96 2.1 il.7 'Wet-Bulb Temperature 0C 24.4 25.5 26.1 25.9 25.6 Standard Deviation i. 79 i. 89 i1.2 $1.4 31.2 Air Velocity m/sec 0.31 0.50 0.69 0.62 0.73 Standard Deviation i. 11 i. 40 i. 39 i. 38 i. 38 - Middle Inside Air Temperature 0C 28.0 30.3 32.0 31.0 30.2 Standard Deviation i1 . 4 i1. 4 i1 . 3 i1 . 6 i1 . 5 Black Globe Temperature 0C 28.7 31.0 32.4 31.5 31.0 Standard Deviation i1 . 5 i1 . 6 ”£1. 3 i1 . 7 il . 6 Wet-Bulb Temperature 0C 24.4 25.5 26.1 25.9 25.6 Standard Deviation :t76 i;89 ii.2 11.4 31.2 Air Velocity ‘m/sec 0.34 0.45 0.48 0.60 0.61 Standard Deviation :t12 2:29 2:31 2:36 :;33 WEST: Inside Air Temperature 0C 28.2 30.3 31.6 31.1 32.1 Standard Deviation :1 . 5 i1 . 3 fl . 5 r1 . 8 r2 . 5 BlaCk Globe Temperature 0C 28.7 31.0 32.5 31.8 34.6 ( continued) Table 4 .1 continue Standard Deviation Wet-Bulb Temperature Standard Deviation Air Velocity Standard Deviation °C m/sec ...37- 24.4 l+ .88 0.44 .29 H- |+ .93 .41 .25 0.45 L32 0.55 i.33 0.57 i.24 Table 4.2 ..38— Means and Standard Deviations of environmental parameters for 15 summer days, 1979 from 8:00 a.m. to 4:00 p.m., under the middle position in the farrowing house. Parameters Units Daytime Hours Position 8.0 10.0 12.0 14.00 16.00 Middle Dry-Bulb Temperature 0C 28.4 30.1 31.6 31.0 30.2 Standard Deviation 0C il.4 :1.4 ”11.3 il.7 i 1.4 Black Globe Temperature 0C 28.8 30.7 32 1 31.5 30 6 Standard Deviation 0C 121.4 il.6 i1 3 421.7 i1 6 Wet-Bulb Temperature 0C 24.6 25.5 26.0 25.6 26.6 Standard Deviation OG :,77 3.93 :1.3 11.2 il.3 Air Velocity m/sec .044 0.52 0.50 0.59 0.52 Standard Deviation 0C :27 f .32 :24 L36 L34 Table 4.3 _39_ for 15 summer days, 1979 from 7:00 a.m. to 5:00 p.m., under two positions in the broiler house. Means and Standard Deviations of environmental parameters Paraneters Units Daytine Hours Position 7.0 9.0 11.0 13.0 15.0 17.0 East Side Inside Air Temperature 0c 28.0 29.3 31.0 31.2 30.0 29.7 Standard Deviation i1.7 i1.5 $1.3 11.6 i 2.1 il.3 Black Globe Tenperature 0c 30. 8 30.3 31. 8 31.7 30.2 30.0 Standard Deviation 353.0 i1.6 i1.2 :1.8 i 1.9 1’1.3 Wet-Bulb Terrperature 0c 23.2 24.3 28.2 25.6 25.0 24.7 Standard Deviation i.71 :t.88 :1.3 :1.4 :1.3i 0.84 Fir Velocity m/sec 0.26 0.59 1.05 1.30 1.08 1.2 Standard Deviation i.0 i.46 :.63 :.72 35.86 t .84 Inside Air Temperature 0c 26.0 28.6 30.8 31.1 31.5 32.2 West Side Standard Deviation fl.3 il.6 i1.1 i1.8 321.3 i0.5 Black Globe Temperature 0c 26.5 29.2 31.5 31.6 31.9 34.2 Standard Deviation :98 :1.9 :1.2 :2.1 :1.3 :0.78 Wet—Bulb Ilemperature 0C 23.0 24.5 25.5 25.3 24.9 25.4 standard Deviation :59 :80 :1.2 :1.5 :1.4 :1.2 Air Velocity m/sec 0.36 0.41 0.83 0.86 0.85 1.03 Standard Deviation 4:.27 :28 :.41 +.43 :.47 :.70 ...40— To document the effects of shaded/mshaded pens with respect to radiant heat load, and feed conversion, an eight-week feed trail was conducted in the broiler house from August 2 to Septenber 27, 1979. Four pens were used for the trial. Fifty broilers in each pen were all fed with the same ration. The feed consumption and animal weight were measured every two weeks. Black globe thermometers were installed in each pen: east, unshaded; east, shaded; west, unshaded; west, shaded; at 0.30 m above the floor. Measurements of the environmental factors were taken from 8:00 a.m. to 4:00 p.m. at two-hour intervals. Similar data were collected during the winter season from January 10 to March 6, 1980. 3.62m 2.1mm ~‘-‘-_—-_-d ><--—-—-—-—-————-— L v 2.75m 2.00m " 2.75m Figure 4.4 Structural modification for broiler housing. Ore pen each on east and west sides of the building was shaded. -41- The data summaries for both periods , for environmental measurements , are presented in Tables 4.4 and 4.5 Data summaries of feed conversion for snmuem'and winter trials are presented in Tables 4.6 and 4.7. 4.5 Computation of the Temperature-Humidity Index (THI) and Black Globe-Humidity Index (BGHI) An accepted equation for Temperature-Humidity Index is: THI = t + 0.36 t + 41.2 db dp where t.db is the dry—bulb temperature, °C tdp is the dew-point temperature, °C The Black Globe-Humidity Index, BGHI, was calculated by inserting the black globe temperature in the THI equation in lieu of the dry-bulb temperature. The values for the dew-point temperatures were computed by using the air psychrometric properties. Tables 4.8, 4.9, 4.10, 4.11 and 4.12 show the values for dew-point temperature, Temperature-Humidity Index, THI, and Black Globe-Humidity Index, BGHI. -42- Table 4 . 4 Means and standard deviations of environmental parameters for summer trials in broiler house frcm August 2 to September 26, 1979. . Daytime Hours . . Parameters Units Sition 8-0 10.0 124] 14-0 1610 East-Side (Shaded) Inside Air Tanperature °c 27.2 30.6 31.1 30.6 30.6 Standard Deviation 11.4 11.6 11.7 11.7 11.2 Outside Air Tarperature 0C 28.0 30.6 31.7 30.6 30.6 Standard Deviation 11.5 12.2 12.2 12.3 11.5 Black Globe Temperature 0C 27.8 31.1 31.7 31.1 30.6 Standard Deviation 11.6 11.6 11.7 11.8 11.2 Wet-Bulb Temperature oC 24.2 26.6 26.0 25.9 25.7 Standard Deviation 11.0 11.2 11.4 11.6 11.3 Air Velocity m/sec 0.31 0.87 0.82 1.07 1.09 Standard Deviation i.l3 1.49 1.50 1.47 1.60 East-Side Inside Air Temperature 0C 28.3 30.0 31.3 30.6 30.0 (“haded’ Standard Deviation i1.9 11.6 11.6 11.6 11.2 Outside Air Temperature 0C 28.0 30.0 31.3 30.6 30.0 Standard Deviatim $1.55 12.2 12.2 12.3 11.5 Black Globe Temperature 0C 29.0 30.6 31.7 30.6 30.6 Standard Deviation 11.9 11.7 11.6 11.7 11.3 wet Bulb Temperature 0C 24.5 25.6 26.3 25.3 25.7 SW Inflation $1.9 11.5 il.8 il.4 ilo3 Air Velocity W580 0.37 0.77 0.93 1.18 1.17 Standard Deviation $.26 i.60 i.53 1.61 11.77 Table 4.4 Continue -43.. 4 mfi-fidJ‘i Inside Air Temperature °c 27.2 30.6 31.1 30.6 30.0 (shaded) Standard Deviation 11.4 11.4 11.6 $1.7 ‘5 1.8 Outside Air Temperature 0C 28.0 30.6 31.1 30.6 30.6 Standard Deviation 11.5 12.2 12.2 12.3 11.5 Black Globe Temperature 0c 27. 8 30.6 31.7 31.1 30.6 smard Deviation fl.6 11.6 11.7 11.8 11.4 Wet Bulb Temperature QC 24.2 25.6 25.9 25.2 25.6 Standard Deviation 11.2 11.5 1 1.4 11.5 11.2 Air Velocity m/eeo 0. 31 0.54 0.59 0.76 0.90 Steward Deviation 1.16 1.42 1.37 1.44 1.63 west-Side Inside Air Temperature 0C 27.2 30.6 31.1 30.6 30.6 (unshaded) Standard Deviation ;11.5 11.4 11.4 11.3 11.3 Outside Air Temperature 0C 28.0 30.6 31.1 30.6 30.6 SW Deviation 11.5 12.2 12.2 12.3 11.5 Black Globe Temperature 0C 27.8 30.6 31.7 31.7 32.2 Standard Deviation 11.5 11.4 11.3 11.6 11.5 Wet Bulb Temperature °c 24.1 25.6 26.0 25.8 25.8 Standard Deviation 1.95 11.5 11.3 11.2 11.3 Air Velocity m/eeo 0.30 0.51 0.73 0.81 0.95 Standard Deviation 1.11 1.34 1.45 1.42 1.65 _44_ Table 4.5 Means and standard deviation of environmental parameters for winter trials in broiler house from January 10 to March 6, 1980. Parameters Units Daytime Hours tPosition 8.0 10.0 12.0 14.0 16.0 East-Side (Shaded) Inside Air Temperature 0C 19.7 23. 25.4 26.4 26.5 Standard Deviation 1.9 12. 13.3 13.5 12.8 Outside Air Temperature °c 19.7 23. 25.4 26.4 26.5 Standard Deviation 11.9 12. 13.3 13.5 12.8 Black Globe Tennerature 0c 22.3 25. 27.3 28.1 27.7 Standard Deviation 2.1 12. 13.3 13.1 12.9 met Bulb Temperature 0c 19.2 21. 22.3 21.8 22.7 Standard Deviation 12.1 a. 12.6 12.4 12.1 Air Velocity m/seo 0.26 0. 0.68 0.94 0.86 Standard Deviation 10.0 1.29 1.40 1.54 1.45 East—Side Inside Air Temperature 0c 19.7 23 25.4 26.4 26.5 (unshaded) Standard Deviation 11.9 12 13.3 13.5 12.8 Outside Air Temperature 0c 19.7 23. 25.4 26.4 26.5 Standard Deviation 11.9 12. 13.3 13.5 12.8 Black Globe Temperature 0C 22.2 25. 27.2 28.1 27.7 Standard Deviation 12.2 3 13.2 13.2 12.9 {let Bulb Temperature 0c 19.2 21 22.3 21.8 22.7 Standard Deviation 12.1 12 12.6 12.4 12.1 Air Velocity m/sec 0.26 0.47 0.68 0.94 0.86 Stardard Deviation i.0 i i.40 i.54 ”$.45 Table 4 . 5 Continue _45_ Inside Air Temperature °c 19.7 23.0 25.4 26.4 26.5 @232? Standard Deviation 11.9 12.5 13.3 13.5 12.8 Outside Air Temperature °c 19.7 23.0 25.4 26.4 26.5 Standard Deviation 11.9 12.5 + 3.3 13.5 12.8 Black Globe Temperature 0C 21.7 25.2 27.3 28.6 28.1 Stanaani Deviation 12.0 12.3 13.0 13.0 13.0 Wet Bulb Temperature °c 19.2 21.2 22.2 21.8 22.7 Standard Deviation 12.1 12.9 12.6 12.4 12.1 Air Velocity m/secO.26 0.47 0.68 0.94 0.86 Standard Deviation 1.0 1.29 1. 40 1.54 1. 45 Inside Air Temperature °c 19.7 23.0 25.4 26.4 26.5 Weigfiéggd) ,Standard Deviation 11.9 11.25 13.3 13.5 12.8 Outside Air Tetnerature 0c 19.7 23.0 25.4 26.4 26.5 Stanaaxa Deviation t1.9 i2.5 i3.3 13,5 i2.8 Black Globe Temperature 00 21.6 25.3 27.5 28.8 31.2 Standard Deviation 12.0 12.2 13.0 3.2 5.0 met Bulb Temperature 0c 19.2 21.2 22.2 21.8 22.7 Standard Deviation 12.1 fl.9 12.6 12.4 12.1 Air Velocity m/seoo.26 0.47 0.68 0.94 0.86 Standard Deviation :20 1.29 140 1.54 1245 -46 OMH. mHH. mmo. vmo. mm.H HN.H 0mm. mom. Nvo. om Aomponmabv mm.m em.m mm.H mo.H vmo. 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Units Position Daytime Hours 8:0 10:0 12:0 14:0 16:0 EaSt'Slde Dew-Point Temperature 0C 22.1 23.0 23.5 23.8 22.7 THI 78.3 80.5 81.8 80.4 81.4 BGHI 82.8 82.5 83.3 81.8 81.6 Dew—Point Temperature 0C 22.5 23.2 23.4 23.6 22.9 Middle THI 77.3 79.8 81.6 80.7 79.6 BGHI 78.0 80.6 82.0 81.2 80.4 [XEW‘POint Tmrature 22.5 23.2 23.4 23.6 22.9 West-Side THI 77.5 79.8 81.2 80.8 81.5 78.0 80.5 82.1 81.5 84.0 BGHI -49— Table 4.9 DEw-Point Temperature, Temperature-Humidity Index and Black Globe—Humidity Index for 15 summer days,1979 in the farrowing house Units Position Daytime Hours 8:0 10:0 12:0 14:0 16:0 Middle Dew—Point Temperature Ct 22.7 23.4 23.6 23.2 24.9 THI 77.8 79.7 81.3 80.5 80.4 BGHI 78.2 80.3 82.0 81.1 81.0 Table 4.10 DewePoint Temperature, Temperature-Humidity Index and Black Glcbe-Humidity Index for 15 summer days,1979 in broiler house. Units Position Daytime Hours 7:0 9:0 11:0 13:0 15:0 17:0 East-side DeWhPoint Temperature ob 20.8 21.9 22.6 23-1 22-7 22.4 THI 76.7 78.4 80.3 80.7 79.4 79.0 BGHI 79.5 79.4 81.1 81.2 79.6 79.3 0 Dew-Point Temperature C 21.3 22.6 23.1 22.7 22.0 22.4 west-Side THI 74.9 77.9 80.3 80.5 80.8 81.5 BGHI 75.4 78.5 81.0 81.0 81.3 83.5 -50- Table 4.11 Dew-Point Temperature, Temperature-Humidity Index and Black Globe-Humidity Index for summer trials in broiler house from August 2 to September 26, 1979. 0 Units Position. East—side Daytime Hours 8:0 10:0 12:0 14:0 16:0 (Shaded) Dewepoint Temperature 0c 22.6 24.8 23.8 23.8 23.5 THI 76.5 80.7 80.9 80.4 80.3 BGiI 77.2 81.2 81.5 81.0 80.3 o East-Side Dew-Point Temperature C 22.6 23.6 24.1 23.0 23.7 (Unshaded) THI 77.6 79.7 81.2 80.0 79.7 BGHI 78.3 80.3 81.6 80.1 80.3 o West-Side Dew-Point Temperature C 22 . 6 23. 3 23. 6 23. 2 23. 6 (Shaded) THI 76.5 80.0 80.8 80.2 79.7 BGHI 77.2 80.2 81.4 80.7 80.0 o West-Side Dew-point Temperature C 22.4 23.3 23.2 23.7 23.5 (Unshaded) THI 76.5 80.0 80.6 80.8 80.7 HSHI 77.1 80.2 81.3 81.4 82.0 -51- Table 4.12 DewePoint Temperature, Temperature-Humidity Index and BlaCk Gldbe-Humidity Index for winter trials in broiler house from January 10 to March 26, 1980. Units Position East-Side Daytime Hours 8:0 10:0 l2:0 14:0 16:0 (Shaded) Dew-Point Temperature 0C 18.5 19.9 20.5 19.3 20.7 THI 67.6 71.4 74.0 74.6 75.2 BGHI 70.2 73.7 75.9 76.3 76.4 o East—Side DewePoint Temperature (3 18.5 19.9 20.5 19.3 20.7 (Unshaded) THI 67.6 71.4 74.0 74.6 75.2 BGHI 70.1 73.8 75.8 76.3 76.4 Dew-point Temperature (33 18.5 19.5 20.5 19.3 20.2 siia:§?e THI 67.6 71.4 74.0 74.6 75.2 BGHI 69.6 73.4 75.9 76.8 76.6 West-Side Dew-Point Temperature 0C 18.5 19.5 20.5 19.3 20.7 (Unshaded) THI 67.6 71.4 74.0 74.6 75.2 BGHI 69.5 73.5 76.1 77.0 79.8 -52- 5 . MODEL VERIFICATION A model provides a tool for the investigation of variations in the design characteristics of the buildings as related to environmental conditions. This chapter presents the results of an investigation of three different building types. The buildings selected for further study were the swine and broiler structures as previously described in Section 4.2 5.1 Determining the Shape Factors of the Surrounding The total radiant heat load on the black globe thermometer is a function of the radiosity and surround shape factor of eaCh component. The surround for the eastewest oriented growing hog house (Fig. 5.1), was divided into two equal hemispherical sections. The lower hemisphere 'was composed of only shadow as there was no unshaded ground. The shadow thus had a shape factor of 0.50. The shape factor for the walls was the arctangent of 0.7/4.0 divided by l80-degrees. Thus, the shape factor for the walls was equal to 0.055. The lower horizon is the 10-degree band of the sky just.above the horizon. The shape factor of the surround with respect to the horizon zone is 0.087. Since the View angle for the walls was 0.055, the shape factor, 0.032, of the horizon was found by subtraction. The shape factor of the cool sky with respect to the globe _53_ was the arctangent of 0.5/4.0 divided by l80-degrees. Thus, the View angle for the cool sky was equal to 7-degrees, and corresponds to a shape factor equal to 0.04. As stated before, the shape factors of all segments of the surround must total 1.0. Similar to the lower hemisphere, the upper hemisphere must add up to 0.50. The shape factor of 0.373, for the shade with respect to the globe was found by subtration. This shape factor of the shade equalled 0.373, and corresponded to a View angle of 134-degrees. ‘ a \ l’ r‘ .------_-----_-__-----_-_.‘._ ‘ ....... --------_--_---°:I K} E SHADOW \\j HOT GROUND “Ofi L 30m Figure 5.1 Cross section of the east-west oriented hog growing house. The globe surround was divided into four components . The lower hemisphere for the east-west oriented farrowing house (Fig. 5.2) , was composed of only shadow as there was not unshaded ground. The shadow thus had a shape factor of 0.50. The shape factor for the walls was the arctangent of 0.8/ 4.0 divided by lBO-degrees, which resulted _54- in a shape factor for the walls equal to 0.063. The shape factor of 0.024 for the lower horizon was found by subtracting the wall shape factor of 0.063 from 0.087. The shape factor for the cool sky was the arctangent of 0.40/4.0 divided by l80-degrees. Thus, the shape factor for the cool sky was 0.032, and corresponded to a view angle of 6-degrees. The sum of the shape factors for the walls, horizon and cool sky, of 0.119 subtracted from 0.50 left a Shape factor for the shade roof equal to 0.381. I \ 2.4m 1r 9 O 3 Figure 5.2 Cross section of the east-west oriented farrowing house. The globe surround was divided into five components. Calculation of the shape factors for the north-south oriented broiler house were more complicated as the shadow moves from west to east , thus, the solar altitude angle and the unshaded ground factor increased as part of the lower hemisphere. In computing the shape factors for the various ..55.. N E N \O or; . i it .t I I - \ “‘~ I ' "”" I ‘5 \ \ i ' I I Fl \ ' I \\ \\ \' 4, / / IA \ "\ ’ SHADE I \ I SHADE ’ COOL Kv\ 'r”//\\" [00/01 v :5 x / ~1~\ HORLZON\.\\ I,/ u . ~\\ 311081 on “' ---- _____4.-.._--_.--L ..... ----.. m +401 6:200:10, ; snnnow i Q07 GRO :- (aiEernoonI L mornin [z \1/ .11 ( 9) Lug] [\ 2.75m 4‘ 2.00m 4‘ 2.75m ’1 Figure 5. 3 Cross section of the north-south oriented broiler house. The globe surround was divided into five components. _56- radiating areas, shadow locations were assumed for two different positions for each the morning and afternoon time. Utilizing the trigonometric functions in Fig. 5.3, it was found that the shape factor in the morning and afternoon of the unshaded ground.with respect to the black globe was the arctangent of 0.30/0.50 divided by 360-degrees. The View angle of the hot ground was 3l-degrees and the shape factor was 0.086. Since the lower hemisphere was made up of only the shadow and hot ground, the shape factor of the Shadow, 0.414, was found by subtraction. This value corresponded to a View factor of the shadow of l49-degrees. The shape factor of the 10-degree zone of the sky just above the horizon was found by geometry to be 0.087. The shape factor for the cool sky was the arc- tangent of 0.8/1.5 divided by 180-degrees. Thus, the shape factor of the cool sky was 0.156. It.was determined that the shape factor for the horizon zone was 0.087 and for the cool sky was 0.156. The sum of these two, 0.246, subtracted from 0.50, left a shape factor for the shade equal to 0.257. The three types of buildings used for verification of the model, generated the shape factors of the segments of the surround with respect to the black globe as presented in Table 5.1. In calculation of the radiant heat load for the north-south oriented broiler house, the shape factors for the shadow were considered 0.50 during the morning and afternoon for the west and east positions repectiv- ely. The shape factor for the directly radiated ground.was considered 0.50 after 3:00 p.m. for the west, and before 9:00 a.mu for the east position. -57- Table 5.1. Values for the shape factors used in the verification of the model, for three different types of housing. Segments Shape Factors for Shape Factors for Shape Factors for of the surround the surround the surround Surround sections sections sections (Hogs House) (Farrow House) (Broiler House) Shadow 0.500 0.500 0.414 Hot Ground 0.086 Walls 0.055 0.063 - Horizon 0.032 0.024 0.087 Cool Sky 0.040 0.032 0.156 Shade 0.373 0.381 0.257 5.2 The Radiosity of the Surround It was necessary to knon the shape factor and the rate of emission of energy from the various sections of the surround to compute the radiant energy falling on the globe. The rate of radiant energy emission from a surface is prOportional to the fourth power of the absolute temperature (Holman, 1976) . The emission rate also varies with the nature of the surface in ccnparison to a perfect black body. The ratio of the actual radiant emission to that of a perfect black body at the same temperature is called emissivity, 8. Thus, for any surface the rate of radiation emission is: R = 80 T4 where R is the rate of emission of energy W/ sq.m. o is the Stefan-Boltzmann constant, 5.67 . 10-8 W/sq.m. °K e is the emissivity -58- For verification of the model all the sections of the surround were assumed to be a perfectly black surface. Therefore, each component of the surround was assigned an emisivity factor equal to 1.0. The temperature value for each section of the surround was calcu- lated or estimated from measured environmental data in the literature. The shadow and wall temperatures were assumed to be equal to the inside air terperature . The shade or roof temperature was calculated using the sol-air temperature approach . The band about lO-degrees high above the horizon was assumed to have a temperature five degrees Celcius above the outside air temperature. Kelly _et 31; (1957) measured the cool sky temperature in the Imperial Valley of California and found it to be approxi- mately lSOC lower than air temperature, A cool sky temperature of 130C lower than air temperature was assumed for this study. The direct sunlight ground temperature was assumed to be 60C above the outside air temperature . 5.3 Validation Simulation studies were conducted on the three different types of building to validate the model . Orientation and structural characteristics were the major variable . For trial purposes environmental conditions were based on average climatic data from Tables 4.1, 4.2 and 4.3. A total of four different trials were performed using different buildings and loca- tions. A summary of the daily test conditions appear in Table 5.2. Structural modifications were made in the broiler house by shading one pen each on the east and west sides of the building. To validate the model, this modified structure was used for two periods: from August 2 to September 27, 1979, and from January 10 to March 6, 1980. Figure 5.4 -59- is a sketch of the modified shading system for the broiler house. This figure shows that the shape factors of the main segments of the modified surround were only shadow, horizon and shade which had the values of 0.500, 0.087, and 0.413, respectively. These two shaded pens were compared with two other unshaded pens. The shape factors for unshaded pens were assumed the same as calculated before. For test purposes environmental conditions were based on average climatic data from Tables 4.4 and 4.5. F x N E. ‘c. I M‘ . , as \\\ . ; “\ l \‘4 I |\\ v 5 I \\ I q. I ‘ \ SHADE ‘\ I k\ I I \\ .._-_Q.. _.___I_._--___.- --.‘s I l #6 ‘V “< 2.75m ’1‘ 2.00m '1 2.75m Figure 5. 4 Cross section of the north-south oriented and modified broiler house . The Globe surround was divided into three components . -60- >.vm o.Hm h.mm hH «.mm o.Nm N.Nm bH a.mm o.om 0.0m NH a.mm 0.0m 0.0m NH o.mm a.mm m.mN p.mm a.mm m.mm p.mm o.vm o.om 0.0m o.Hm N.Hm mH mH vH MH o.mm m.¢m o.mN m.mm o.Nm N.Nm p.mm o.vm o.Nm m.Hm m.Hm H.Hm pH mH vH MH o.mN o.om p.mm p.mm m.Hm m.Nm p.mm o.vm N.om m.om o.Hm m.Hm pH mH «H MH p.mm o.mm a.mm o.oN o.Hm m.mm p.mm o.vm N.om m.om o.Hm m.Hm pH mH vH MH m.mm o.vm o.Nm NH o.mN m.¢m o.Nm NH o.mN m.vm o.mm NH h.om m.vm o.mm NH N.mm a.mm o.Hm HH m.mm o.mm m.om HH m.mN o.mm o.Hm HH a.mm o.mm o.Hm HH o.mm o.mm 0.0m OH o.mm o.Nm o.om 0H m.mm o.Nm H.om OH m.mN o.mm m.om OH 03 $03 a.m.Sm m6 392 mad 8m? 3803/ .34 m . mm oo 8563989 glam: 0 .mm 00 muspmummaoe H2 @3350 a.mm oo mfiufimofie m2 momma e whom I minted coflHmom ummm I mmsom HoHHOHm 3 9”on mm8m mo £84 omm\E m>.o o ommxa >UHOOHm> see 0 . mm 00 mmfimumefie 83:3» 0 . mm 00 ouspmuonwfiwe H2 monuso o . mm oo mushmumefie H2 63min n musom I QEHuzoo 8368 “mm: I $58 “838m ofl 683 m Loom NO 394 omd com? 383$, a m . mm oo $538989 £5an 0 . R oo 8536969 u? 6338 o . hm oomHBmumxewe H2 835 e mason I 9&3 cofifimom 2632 I 853 mggm 03 68$ m..q_8m no 394 cm .0 08? 383$, 34 m . mm 00 8268989 bimbo: o . hm Downsumgma H2 oonuso o.hm oomHsumungoE.Hfle.mondH e .Som I maniac QOHaHmom oHooHE I 9303 mmom .mNaHHmm I g Hoficou .mosuflmq fihoz 05H no . $33 mhmo HmEBm. S.” @3903 m0 womb mossy How .mfiHmoQu one. “Emu on omm: gm Boo .N.m mHonB -61- 5.4 Results and Discussion The Temperature-Humidity Index (THI) and the Black Globe-Humidity Index (BGHI) were calculated by using the simulationzmodel. .Measured THI and BGHI, along with the model predicted THI and BGHI for a summer period in Belize, are plotted for different housing systems in Figures 5.5 through 5.12. Data for all predicted values are tabulated in Appendix C. No significant difference existed between dry-bulb air temperatures measured inside and outside the livestock houses. The housing structures thus had no effect on modifying ambient air temperature, which is in agree- ment with results from research done in California (Garret etnal., 1967, Kelly et 31., 1950). A summary of the climatological parameters measured during 15 days in July, 1979 in Belize for both swine and broiler houses, is presented in Tables 4.1, 4.2 and 4.3. For a period from August 2 to September 26, climatological parameters were measured in a modified broiler house and are presented in Table 4.4. Black globe temperatures were measured to determine hOW‘Well the globe temperature integrated the effects of dry- bulb temperature, air movement and radiation. Although the housing system.does not effectively reduce the ambient air temperature, it is effective in reducing the combined effects of dry-bulb temperature, air movement and radiation by essentially acting as a radiation shield. The combined effects of air temperature and humidity have been re- lated to animal comfort and performance by THI, as discussed before. To create an index integrating dry-bulb temperature, humidity, radiation and air movement the Black Globe-Humidity Index (BGHI) was developed by ~62- inserting the black globe temperature in the THI equation in lieu of the dry-bulb temperature. The significant difference between the THI and BGHI under a shade structure was tested by checking the level of difference between dry-bulb air temperature and.black globe temperature under similar conditions. By using the paired comparison, t-test (Bhattacharyya and JOhnson, 1977), bladk globe temperature was significantly higher at the 95% probability level than dry-bulb air temperature under the swine and broiler houses. No significant difference at the 95% probability level existed between dry- bulb air temperature and black globe temperature in the east side of the north-south oriented broiler house at 5:00 p.m. Thus, under some condi- tion, BGHI was found to be significantly higher at the 95% probability level than THI. However, no significant difference existed between the THI and BGHI at 5:00 p.m. in the east position of the broiler house, as there was no significant difference between the dry-bulb air tempera- ture and black globe temperature. The graphs (Figures 5.5, 5.6,.5.9,5.10,5.ll, and 5.12) show the THI and BGHI indices throughout the day from 8:00 a.m. to 4:00 p.m. Figures 5.7 and 5.8 show the indices in the broiler house from.7:00 a.mm to 5:00 p.m. .Measured values for THI and BGHI are plotted at two-hour intervals. Predicted values for THI and BGHI are plotted at one-hour intervals. Figures 5.5 and 5.6 present measured and predicted values for THI and BGHI in eastrwest oriented livestock houses at the middle position fOr the summer period. Minimum values for THI and BGHI were at 8:00 a.m., and maximum values were reached at 12:00 noon. The results from the north- south oriented broiler house are presented in Fig. 5.7 for the east posi- -63- tion and Fig. 5.8 for the west position. On the east side, the shape of the curve shows that the values for THI and BGHI spread more from 7:00 to 9:00 a.m., and reached the maximum at 12:00 noon. However, on the west side the maximum value for the THI was at 12:00 noon and the maximum value for the BGHI was at 4:00 p.m. The maximum value for BGHI at 4:00 p.m. was related to the effect of the direct sun radiation on the pens, and consequently, the animals or the black globe were exposed to a larger percentage of the hot ground, tending to decrease the shadow effect. Structural modifications were made on one pen on each the east and the west sides of the north-south broiler house to shield direct solar radiation from inside the structure. Figures 5.9 and 5.10 represent the results from shaded and unshaded pens on the east side of the house. The graphs show that the maximum value for BGHI for the unshaded pen was 81.6, compared with a value of 81.5 for the shaded pen. Figures 5.11 and 5.12 represent the results from shaded and unshaded pens on the west side of the broiler. house. The shaded west pen (Fig. 5.11) differed from the unshaded west pen (Fig. 5.12) in that during the afternoon the unshaded pen received direct solar radiation, thus increasing the values for BGHI which reached a maximum value at 4:00 p.m. Shading one pen on the west side of the broiler house reduced the value of BGHI by 2.0 at 4:00. This difference was important in considering animal stress as can be seen in the Conclusions . Higher prediced THI and BGHI than measured occurred during the high intensity solar radiation periods from 11:00 a.m. to 2:00 p.m. This indicated that the measured roof surface temperature of the house was _64... lower than the model predicted. There was some tendency for the model to predict higher THI and BGHI primarily during the highest outside air temperature hours of the day. The higher predicted values were more evident for houses with galvanized zinc type roofs (see Figures 5.5 and 5.6). The insulation of a thatch type roof along with the rough surfaces, prevented the solar radiation from having a noticeable effect on heat exchanged to the surroundings. Due to this factor, the model appeared to function equally well on any time of the day for thatCh roofing. The order of magnitude comparison of predicted Black Globe-Humidity Index and/or Temperature-Humidity Index with calculations using blaCk globe temperature, dry-bulb air temperature and wetrbulb temperature, and air velocity revealed no major discrepancies between.measured and model predicted values. INDICES 83 82 8] 80 79 78 77 -65- ‘_.____.Measured TH I—---—-——-—-« Predicted mm H—HlMeasured l -—4——-TPredicted HI 7 7 , _ 6:00 8:00 10:00 12:00 ih:00 16:00 Daytime - Hours Figure 5.5 - Measured and predicted values for THI and BGHI du the summer period at the middle position of the e west oriented hog house. ring as t’ INDICES 83 82 81 80 79 78 77 -66.. Measured T l _L Predicted HI r 4‘ Measured 8 HI L.-——L———-J| Predicted GHI 6:00 8:00 10:00 12:00 19:00 16:00 Daytime - Hours Figure 5.6 - Measured and predicted values for THI and BGHI during the summer period at the middle position of the east- west oriented farrowing house. INDICES -67- 82 81 80 79 / 78 . ;{ IV ' I, Measured Ttl / 11’ --...-”1Predicted THI 77 v ‘ Measured BfiHl -_+—-—+ Predicted BGHI 76 , 6:00 8:00 10:00 12:00 14:00 16:00 Daytime - Hours Figure 5.7 - Measured and predicted values for THI and BGHI during the summer period at the east position of the north- south oriented broiler house. INDICES (D L/J 82 80 79 78 77 76 75 -68- xi“ / —_1.—_ p 4 JMeasured THI ‘L__9?__4D9redicteo T'H'l is Measured BGHI 11L.— -4.--» Predicted BGHI 6:00 8:03 10:?3 12700 1b:OO 16:00 Davtime - Hours Figure 5.8 - Measured and predicted values for THI and BGHI during the summer period at the west position of the north- south oriented broiler house. lNDlCES -69- 82 .__ 81 80 79 P4 Measured THI 78 v +--_9__.49 Predicted THI iii 5. Measured BGHI IL- —A - --diPredicted BGHI 77 76 6:00 8:00 10:00 12:00 14:00 16:00 Daytime - Hours Figure 5.9 - Measured and predicted values for THI and BGHI for a period from August 2 to September 26, at the east- shaded position of the north-south oriented broiler house. INDICES 83 82 81 80 79 78 77 -70- 1 I” ’/ r———o——$ Measured TI'II I ’/ 1’, -—-0---1D Predicted THI I eA Measured BQHI __+__4rPredicted BGHI 6:00 8:00 10:00 12:00 14:00 16:00 Daytime -Hours Figure 5.10 - Measured and predicted values for THI and BGHI for a period from August 2 to September 26, at the east- unshaded position of the north-south oriented broiler house. INDICES -71. 82 81 \\‘ e\\ \ 80 y 79 I 78 .p p’Measured THI ---€>- ---<>Predicted THI 77 HA Measured BGHI A-——-—-e————45Predicted BSHI 76 6:00 8:00 10:00 12:00 19:00 16:00 Daytime - Hours Figure 5.11 - Measured and predicted values for THI and BGHI for a period from August 2 to September 26, at the west- shaded position of the north-south oriented broiler house. INDICES 83 82 81 80 79 78 77 76 -72- h ,4 / / i_1rf /' / -—-m‘ I, ,’// \\\ I 1’ 7“.“ / “19 I 1 I / I/I // ll / l T / // ‘ . ‘ Measured THI / é} ___G_.__0Predicted THI 3; Measured BGHI +-_+-_.‘ Predicted BGHI 6:00 8:00 10:00 12:00 14:00 16:00 Daytime - Hours Figure 5.12 - Measured and predicted values for THI and BGHI for a period from August 2 to September 26, at the west- unshaded position of the north-south oriented broiler house. -73- 6. SIMULATION STUDIES 6.1 Typical Layout of Tropical livestock Housing System The model was formulated to have a usefulness as a tool in the study of alternative structural design characteristics which affect the inside environmental conditions . This chapter presents the results of simulation studies of two typical tropical livestock housing systems . A proposed housing system designed to minimize radiant heat loads is presented. The typical livestock structure in Latin America has a gable roof; concrete floor; concrete block, bricks or slated wood walls. The availa- bility and cost of roof, wall and floor materials varies from country to country depending upon local resources and technology. In Belize the most common roofing materials were galvanized steel, thatch or wood. Walls were made of wood although the concrete block industry was developing. In Brazil roofing materials range from thatch to aluminium, galvanized steel, cement asbestos, plywood, several types of plastic, but clay tile dominates. Walls are usually constructed with bricks, concrete block or adobe. TWO typical layouts of tropical livestock housing systems that differ mainly in wall construction are shown in Figures 6.1 and 6.2 The total radiant heat load on the black globe is a function of the radiosity of the various segments of the surround. The structures selected for these studies were oriented east-west to provide maximum shading ef- ficiency. _74_ The first layout represents an eastewest oriented swine house whidh had: 3.0 m in. height, 1.5 m ridge roof, half walls, 1.5 m high, and concrete floor. Fig. 6.3 shows that the surround was divided in four segments: shadow, walls, cool sky, and shade. The second structure rep— resents a typical broiler house in tropical areas. The house character- istics were as follows: 3.0 m high with a 1.5 m ridge roof, 0.8 m high brick and 2.2 m high wire screen walls. Fig. 6.4 shows that the surround was divided into five setments: shadowy walls, horizon, cool sky and shade. The calculation of radiation from the surround was determined by using the same technique discussed in Section 5.1. The sumround for both types of houses was divided into two equal hemispherical sections. The lower hemisphere was composed of only the shadow as there was no hot ground. The shadow thus had a shape factor of 0.50. These two types of housing systems used for the simulation studies, had shape factors with respect to the globe as presented in Table 6.1. Table 6.1 - values for the shape factors used in the simulation stuiies, for two different housing systems. . Section Shape factors Shape factors surround for the surround for the surround sections sections *( TYpe I housing) **( Type II housing ) Shadow 0.500 0.500 Walls 0.089 0.024 Horizon 0.063 Cool Sky 0.161 0.146 Shade 0.250 0.267 * Type I housing - The east-west oriented swine house ** Type II housing - The east-west oriented broiler house -77- .mmsofi HwHHoun ooucwHHo pmozlumcm use .mchsos HH damp How “Bowed N . o 8de V \ J /// /// .mecwcomeoo Hoom oncH oQoH>Ho mm3_ocsonnsm onon use .mchsos H damn mo coHuumm mmono m.m mHsmHm -78- U190 3 8 < I <1) ‘I ‘l ‘ ‘8‘ W01 _1 2‘ 3 I I l I I {H 1| 1I II II lI Mail \I \l I I \ I‘D ’I l I I I I I I i 1 l 1 1 I I l I I I I I I 1 11108 >. X (I) § 0 \ \ \ I I AIZ -79- 98 8.5 833a was @8088 83m 9e. .mucoconwcoo .mchoos HH damp mo cofloom mmoso e6 magma ZONEOIII LUO'S {when ' >>OO an haemam Hove: Hmum cam Hue semumHeam manage no mmHeemxm .m.e mHhme _95_ 3) black painted under surface of an aluminum shades. At 1:00 p.m, under the same environmental conditions , the air temperature was 34 °C. Unpainted aluminum shade presented the highest radiant heat load on the globe, 590.0 W/m2 compared to 568.0 W/m2 for white tOp, plain bottom and 549.0 W/m2 for plain top, black bottom aluminum. These quantities of radiant energy resulted in a 4.6 difference between measured values for THI and BGHI under unpainted aluminum shade; a 3.4difference under white top, plain bottom aluminum; and a 2.4 difference under plain top, black bottom aluminum shade. Plain top, black bottom was shown to be more efficient in reducing radiant energy. The radiant heat load from the underside of an unpainted metal roof can be as high as 41.0 W/m2 of animal surface. The predicted values for BGHI, from radiation studies of livestock shades in California, have shown good results from shade structures, 16 x 24 x 10 feet high (See examples 1 through 4, Table 6.3) . Predicted values for BGHI were lower from shade structures , 8 x 8 x 4 feet high (See examples 5, 6 and 7, Table 6 . 3) . The lower values were attributed to the fact that the percentage of radiant energy leaving a surface per unit area was not well determined. Table 6. 3 presents the shape factors of 0.43 for shadow, 0.08 for hot ground, and 0.13 for cool sky. As the height of the shade is decreased the animals or globe in the shadow become exposed to a higher percentage of unshaded ground, which tends to decrease the cool sky effect (Kelly gt _a_l_., 1954) . lowering the height of the shade increases the proportionate value of radiant energy from the lower hemisphere . -96.. 7. SLMlARY AND CONCLUSIONS 7.1 Summary Field research was conducted during the sumer of 1979 at the Cen- tral Farm Experimental Station in Belize. Hot weather environmental conditions under different livestock housing conditions were evaluated. Three types of houses were evaluated. These buildings differed in structural characteristics, dimensions and orientation. The radiant heat load on animals in the houses was measured with black globe thermometers. The Black Globe-Humidity Index was utilized as an indication of the level of comfort or discomfort under various environmental conditions. Structural modifications were made on a broiler growing building to shield direct solar radiation from penetrating the inside of the structure. An eight-week feed trial was conducted to measure the effect of shaded/unshaded pens in terms of the Black Globe Humidity-Index and feed conversion. The results are summarized in Tables 4.6, 4.7, 4.11, and 4.12. A mathematical model was developed to simulate the radiant heat load, black globe temperature, Temperature-Humidity Index, and Black Globe-Humidity Index as functions of solar radiation, shade materials, walls, housing dimensions, air velocity, inside and outside air tempera— ture and wet-bulb temperature. Environmental data from field studies were used to verify the model performance. -97- Simulation studies were made to study the effect of alternative structural design characteristics on the inside environmental conditions . Two tropical livestock housing systems and four different roof materials were used in the simulation studies . The environmental conditions were based on climatic data at the Central Farm Station in the Belize Valley. A typical summer day for Central Farm was assumed for simulation. 7 . 2 Conclusions The following six conclusions have been formulated from the field research , and simulation and model verification studies conducted during this project: 1. The BGHI was reduced from 82 to 80 during the sumer in Belize by shielding direct radiation into one pen on the west side of the broiler house. However, similar shading the east side yielded no reduction of the BGHI. 2. Feed conversion for broilers in Belize in the experimental house was affected by the birds age and growth seasons. In summer, when the BGHI ranged from 77 at 8:00 a.m. to 82 at 4:00 p.m., feed conversion was 35% lower for the first four weeks than in winter when BGHI ranged from 70 at 8:00 a.m. to 80 at 4:00 p.m. (the birds suffered in cold weather) . From the fourth to sixth week there was no difference in feed con— version between seasons. Frcm the sixth to the eighth week the feed efficiency was 20% lower in winter than in summer (the birds suffered in hot weather) . 3 . The simulation model developed in this study predicted environ- mental conditions within an 98% range of measured values . 4. _9 8— The BGHI, both measured and predicted, were consistently about 0.5 higher than the THI under little or moderate heat load conditions. This difference increased to 4.0 under high heat load environmental conditions. The BGHI provided an indicator of comfrot which included the significant additional radiation heat load under hot.weather conditions. Galvanized steel roof with 3.0 cm of insulation beneath is com- parable to thatch and better than a1uminum.or clay tile in terms of reducing heat load on the animals under the shade. Thatch roofing reduces the radiant heat load by 10.0 W/mz of animal surface compared to plain galvanized steel, 5.0 W/mz to clay tile and 2.0 W/m2 to aluminum. Thus, thatch is a better shading material than galvanized steel, aluminum and clay tile for hot weather conditions. 7.3 Recommendations for Future Wbrk The results of this research suggest the need for additional work in the following areas: 1. Measurement of the inside roof surface temperature for different types of materials. These actual values are needed to further verify the predicted values from the sol-air temperature approadh. Investigation of the ground surface temperature at different conditions: before and after shading, with various types of floor and various times during the day. A detailed invetigation of the relationship of livestoCk _99_ production to the BGEH . This should include physiological response to environmental stress as a function of the animal age , weight , and breed . Determination of the economic benefits of environmental modification in preventing the decline of animal production . Reorganization of the simulation model so that it can be used to study the influence of the structural design characteristics on the inside environmental conditions in the sourthern hemi sphere . -100- REFERENCES American Society of Heating, Refrigeration and Air Conditioning Engineers. ASHRAE Handbook of Fundamentals. New York. ASHRAE, 1977. Bedford, T. and Warner, C.G. 1934. The Globe Thermometer in Studies of Heating and ventilation. The Journal of Hygiene. V01. 34 (4): 544-549. Berry, I.L., M.D. Shanklin and Johnson 1964. Dairy Shelter Design Based on Milk Production Decline as Affected by Temperature and Humidity. Transactions of American Society of Agricultural Engineers 7 (3): 329-331. Bhattacharyya, G.K. and R.A. Johnson 1977. Statistical Concepts and Methods. JOhn Wiley & Sons, New York, N.Y. 639pp Biana, W. 1965. Cattle in a hot environment. The Journal of Dairy Research. Cambridge - The University of Press. 291—345 pp. Biana, W. 1970. Animal Response to Meterorological Stress as a Function of Age. Bicmeteorology 4 (1): 119-131. Bond, T.E. and C.F. Kelly 1955. The Globe Thermometer in Agricultural Research. Agricultural Engineering V01. 36: 251-255. Bond, T.E., C.F. Kelly, S.R. Nbrrison and N. Pereira 1967. Solar, Atmospheric, and Terrestrial Radiation Received by Shaded and Unshaded Animals. Transaction of American Society of Agricultural Encineers 10: 622-627. Bond, T.E., C.F. Kelly and S.R..Morrison 1968. Influence of Surroundings on Radiant Heat Load of Animals. Transactions of American Societv of Agricultural Engineers: 246—248. Buffington, D.E., A. Oollazo—Arocho, G.H. Canton, D. Pitt, W.W. Thatcher, and R.J. Collier 1977a. Black Globe-Humidity Comfort Index for Dairy Cows. American Society of Agricultural Engineers, Paper No. 77-4517. Buffington, D.E., G.H. Canton, R.J. Collier 1979. Inspired - Air Cooling for Dairy Cows. American Society of Agricultural Engineers, Paper No. 79—4510. Cargil, B.F. and R.E. Stewart 1966. Effect of Humidity on total heat and total vapor dissipation of Holstein Cows. Transactions of American Society of Agricultural Engineers 9: 702—207. -101- Costa, M.A. 1980. The Evaluation of Indigenous Feedstuffs for Nutrition of Swine and Poultry in Belize. Master of Science Thesis, Department of Animal Husbandry, Michigan State University, East Lansing, MI. Esmay, M.L. 1969. Principles of Animal Environment. AVI Publishing Co., Westport, CT 325 pp. Garret, W.N., T.E. Bond and N. Pereira. 1967. Influence of shade height on physiological responses of cattle during hot weather. Transac- tions of ASAE 10: 433. Holman, J.P. 1976. Heat Transfer - fourth edition. McGraw-Hill Book Company, New York, N.Y. 530 pp. Kelly, C.F., T.E. Bond and N.R. Ittner 1950. Thermal Design of Live- stock Shades. Agricultural Engineering, Vol. 31, No. 12 601-606 pp. Kerslake, D. Mck 1972. The Stress of Hot Environment. Cambridge Univer- sity Press. Bentley House, london. 316 pp. Kelly, C.F., T.E. Bond and N.R. Ittner. 1957. Cold Spots in the Sky May Help Cool Livestock. Agricultural Engineering, Vol. 38 (10): 726-729. Lerew, C.F. and F.W. Bakker-Arkema. 1975. Guide to the Use of SYCHARP A FORI‘RAIN Psychrometric Package. Michigan State University, East Lansing, MI. 21 pp. Mackey, C.O. and L.T. Wright, Jr. 1946. Periodic heat flow—composite walls and roofs. ASH&VE Transactions, Vol. 52, 283-296 pp. Mackey, C.O. and L.T. Wright, Jr., 1944. Periodic Heat Flow - Homogeneou Walls or lbofs. ASH&VE Transactions Vol. 50, 293-312 pp. McAdams, W.H. 1954. Heat Transmission, 3rd edition, Chapter 2. McGraw Hill Book Company, New York, N.Y., 532 pp. I‘bntheith, J.L., L.E. Nbunt 1973. Heat loss From Animal and Man, Assess- ment and Control. Butterworth & Co., Ltd., london, 457 pp. Raber, B.F. and F.W. Hutchinson 1950. Panel Heating and Cooling Analysis. Chapter X, John Wiley and Sons, Inc. 117-138 pp. Reifsnyder, W.E. 1967. Radiation Geometry in the Measurement and Inter pretation of Radiation Balance. “gricultural Meterology 4 (1967) 255-265. Thom, E.C. 1958. Cooling degree—days. Air Conditioning, Heating, and Ventilation. July, 1958. U.S. Weather Bureau, 1959. Instruction to field stations from experimental use of discomfort index. March, 1958. -102- Vernon, H.M. 1932. Radiant heat in relation to human comfort. Journal of Industrial Hygiene. 14: 95-111. Yaglou, C.P. and D. Minard 1957. Control of heat casualities at military training centers. Ami Med. Assoc. Archs Ind. Hlth 16, 302-316. -103- APPENDICES -104- APPENDIX A COMPUTER PROGRAM LISTING | ' v I HUI bfAlrlR INDEX _~. o.‘ 1.!“ 1.0181091110 13 .‘|1 ‘01 \ Hurlhllv l . L X.‘ 1'“ 0’ firUlH fh x'lftvo.) TEMP-.V¥.I(Lo' lihfl q Ul'hP9(2“) THL P‘l-uli- L “If HPS‘U‘O)Q 89"VL1 L lHlJL Al I..; l 091 II/‘1.X.all(|'1~a,' g7 LHADO.‘I,aHr0N SULAP0(erUI.(UIlUI.ILP"=Ihful.lhr'c=gnlpu1) 7h/17H PWHW4H “OLARC (‘aaaaat'NVIK-(mHFNTAL CUH‘ 111')” (at... (aaaaaL PROGRAH lb -105- .. o 4 >4 A ‘ v— . J N ; o u- o q .1 u’; 4‘. O r —I O o J‘ N o x O 1 O o J) :1 A (‘1 w- (‘1 _a A 0 o If a g r A o 8 o o _,‘ : .n O l C —-1 O N a V. O C n ... o A - .. e A C a o n o g, t A v t. 'J) O o o t 3 _'. -..‘ v.1 \ "I .‘u o "4 .1 A ._ 3 O \L J h .. o i- D A ‘. L. I - “(I .1 9 "‘ h \ ", _J '— 6' I. II 1‘. ... u o "a 2 L; r- v .' > --. 39 u . - 9 v t u o g t v J -_ 7 .4 - o 1. ‘ "7‘ t' (. (C; U 2 .~ r o 4 7 v 4 k * z :1 d o o o a z :' 1 o c " d A A CIA L L . 0 an .. -‘ A .2 J a) .. A ..Jh- _- v— I , c 1 A ..', b '1 -. I a. l. 0" 3 -\ -\ . _I J __ 0 r1 ’- : z ... L) “Iv n P O o .7 F ._ a A ;_4 w .J A :3 A P ‘~ 40 a. ., o u v— ... A4 .L _-- t. t. \— J .. tr 2'. ..v. - .. 5 J l— P— I— ‘—'~ -- V'— ‘I Q "‘ L t V _J of.” - _ - c. . >-.. .AJI - q .. ... v .. - a _ 5 o o _. .. .. ..-—A}!- ~-— .L z. >- u- .. F'O ‘ i o o o 1 v u- -.VJG~: (C. 3 3 .Z Z .J a 0 v e .3 7 > HO_.>-".': '1 .‘. ‘ . tl j. 2 .. x t‘ ’. __. 7 av- «V 91 --s L) r- 3 .15 1 n. a— : o o\ '- L. Q _J Au”: J. L 1: Z r- 0- - ( u'. I“: >— ._‘ o\ o o 0 2 C‘ >< 'L '-_.‘~...—IZ£ A; t... .. d ( :r x 0'04 1‘ o o ‘\ . q . 7: o ' _at ”DC _ ‘d . .. — .1 __ o O. u . — ¢qrono » r a g LAJT~¢ bid 1 3 2 P 3 H v £0 a z... ‘. o '. o o .‘. .— r- -. - OQU“ul-I.L .‘LLC .— r— 4 Q o— r \ (A 7 — ooooo ,_ —- .1 .H. o~(\< _‘ I, h _, _1 u— < ... 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L0 dzwghroxhk _aIOLou u; uzuuwn- ”v-4--u0u|eed1mcugmohum ‘1:\ L;\:"'...‘-’...0 0..\r-t—\1\p- —“;v--r— qr—L'Akgv—vr—\r-~>- n—Jr—co— v r-c.’;r-g._.oe "r— o\Z>- Let. 4.] “.‘..-._.Ia..JH_.<-ourl_.._..l ..l .. _J—JCJ 1.1“ _l - . r . n — w : :. 1 2 ; J I - ou;'_u3 _~:i»: an-" h-ch—dcl- 4’.“ 0:41:44 d—dgzp- 4 dudumgzfiqdp L; ... u. uh s— oa—Caaxu r-a‘r- -—>- op—"v-t‘v—u-o—v—xt— r-_)C“ II_._b-.JH_Jt—v3>._.l-_Z'.J‘ _L .1 «II-pa-i..u._l.l lccquMZUC a c a c a c c a a. a a a c a c a a a a c a a a a c a a g a a a 0 a a a a a c a a I a a o a a c a a ' o a a a a c c c o c c a a a c a a a .. _aa a a a a a a a I c C I o C c I g i C c c c C I O C C L.) L, U k.- U U LU L. U LA. U U U L— ; U U p U . in ‘4 .0 “i In 3 in U n :D in N fl ” c c m m o a s p 1 “'0 'T=1 ()9 74/175 SOLARG PROGRAM v n + Li; CI. A :3 a- t- N <1 G a: A I I,“ (A A a G. 3 Lu A 2 H 2 0 Lu L) u—o ~1' #- ..J r— A c u D U. a LL. 0 C D A F— K H O D to cm L: CC .1 to D ..1 H A -O c: m u; 1'. N (I) u: u A 0 ct Lu 2 H c 4 <1 C. 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K o— -lO8- APPENDIX B VERIFICATION STUDY DATA -109- Table B.l Experimental sample data for hogs growing house at middle position, from July 6 to 22, 1979. Black Globe Inside Air 0 Wet-Bulb Air Velocity Hour Temperature C Temperature C Temperature C m/sec 8:00 30.0 29.4 25.0 0.26 28.9 28.3 23.9 0.26 30.0 28.3 23.3 0.52 27.8 27.2 24.4 0.26 29.4 28.8 23.9 0.26 29.4 28.9 25.0 0.26 32.2 31.7 26.7 0.52 28.3 27.8 25.0 0.26 28.3 27.8 24.4 0.26 27.2 26.7 24.4 0.52 29.4 28.9 24.4 0.52 26.7 26.7 23.9 0.26 26.7 26.0 23.9 0.26 27.8 27.8 23.9 0.52 28.3 28.3 24.4 0.26 10:00 28.9 28.3 25.0 0.26 30.6 30.0 25.0 0.26 31.7 30.6 25.0 0.26 35.0 33.9 26.7 0.77 32.2 31.7 26.7 0.26 31.7 31.7 26.7 0.77 31.7 30.6 26.7 0.77 31.7 30.6 26.0 1.03 30.6 29.4 23.9 1.03 31.7 30.6 25.6 0.52 29.4 28.9 24.4 0.52 29.4 29.4 25.0 0.26 31.7 30.6 25.0 0.26 29.4 28.9 25.0 0.26 -110- Table B.l (continued) Black Globe0 Inside Air Wet-Bulb 0 Air Velocity Hour Temperature C Temperature C Temperature C m/sec 29.4 29.4 25.6 0.26 12:00 33.9 33.3 26.7 1.03 31.7 31.1 26.7 0.26 32.2 31.7 26.7 0.26 32.2 31.7 26.0 0.26 33.3 32.8 26.7 0.77 33.9 33.3 26.7 0.26 33.9 33.9 28.3 0.26 33.9 33.3 27.8 0.52 33.3 32.2 26.0 0.26 31.7 31.7 23.9 1.03 32.2 31.7 26.0 0.77 32.2 31.7 25.6 0.77 31.7 30.6 25.0 0.26 32.2 31.7 25.0 1.03 28.9 28.3 23.9 0.26 32.2 31.7 26.0 0.26 14:00 32.2 31.7 26.7 1.03 30.6 30.6 27.2 0.52 28.3 27.8 24.4 0.26 31.7 31.1 26.0 0.77 33.3 32.8 27.8 0.26 33.9 33.3 28.3 1.03 33.3 32.2 26.7 1.03 31.7 31.7 23.3 1.03 32.2 31.7 25.0 1.03 31.7 30.6 25.6 0.26 32.2 31.7 25.6 1.03 28.3 28.3 24.4 0.26 -111- Table B.l (continued) Black Globe Inside Air 0 Wet-Bulb 0 Air Velocity Hour Temperature C Temperature C Temperature C m/sec 29.4 29.4 25.6 0.26 32.2 31.7 25.6 0.52 16:00 31.1 30.6 25.6 0.52 30.6 30.0 25.6 0.26 32.2 31.7 26.0 1.03 32.8 32.2 27.2 0.52 32.8 30.6 27.8 0.77 31.7 30.6 25.6 1.28 31.7 31.7 23.9 0.26 29.4 28.9 25.0 0.26 29.4 28.9 24.4 0.52 27.8 27.2 23.9 0.52 30.6 29.4 26.0 0.52 —112— Table 8.2 Experimental sample data for farrowing house at middle position, from July 6 to 22, 1979. Black Globe Inside Air Wet-Bulb Air Velocity Hour Temperature 0C Temperature 0C Temperature 0C m/sec 8:00 30.0 28.9 25.0 0.26 28.3 27.8 24.4 0.26 29.4 29.4 25.0 0.52 30.0 30.0 25.0 0.52 28.9 27.8 24.4 0.52 29.4 28.9 25.0 0.26 31.7 31.7 26.7 1.03 28.3 28.3 24.4 0.26 29.4 28.9 24.4 0.26 27.2 26.7 23.9 0.52 26.7 26.0 23.3 1.03 26.7 26.7 23.9 0.26 28.3 28.3 24.4 0.26 28.3 28.3 24.4 0.26 10:00 28.3 27.8 24.4 0.52 30.0 29.4 25.6 0.26 30.6 30.0 24.4 0.26 33.9 33.3 26.7 0.77 33.3 32.2 26.7 0.26 31.7 31.7 26.7 1.29 31.7 30.6 26.7 0.77 31.7 30.6 26.0 0.52 29.4 29.4 23.9 0.26 31.7 30.6 25.6 0.26 29.4 29.4 24.4 0.52 29.4 28.9 25.6 0.52 29.4 29.4 25.0 0.26 29.4 28.9 25.6 1.03 30.6 29.4 25.6 0.26 *113- Table 8.2 (continued) Black Globe Inside Air Net-Bulb Air Velocity Hour Temperature C Temperature C Temperature C m/sec 12:00 32.2 32.2 26.0 0.52 31.7 31.1 26.7 0.77 32.2 31.7 26.7 0.26 32.2 31.7 26.0 0.26 32.8 32.2 26.7 0.77 33.9 33.3 27.2 0.26 33.9 33.3 27.8 0.52 33.9 33.3 28.3 0.77 31.7 31.7 26.0 0.26 31.7 30.6 23.9 1.03 32.2 31.7 25.6 0.52 31.7 31.7 25.0 0.52 31.7 30.6 25.0 0.26 31.7 30.6 25.0 0.52 28.9 28.3 23.9 0.52 32.8 31.7 26.7 0.26 14:00 32.2 31.1 25.6 0.77 31.7 31.1 26.7 0.26 27.8 27.2 24.4 0.26 31.7 31.7 26.0 0.52 33.3 32.8 27.2 0.26 33.9 33.3 27.8 1.03 32.2 31.7 26.0 1.29 32.2 31.7 23.9 0.77 31.7 31.7 25.0 1.03 31.7 30.6 25.0 0.26 32.2 31.7 25.0 0.77 28.3 27.8 23.9 0.26 29.4 29.4 25.6 0.26 32.2 31.7 25.6 0.52 -ll4- Table 8.2 (continued) Black Globe Inside Air Wet-Bulb Air Velocity Hour Temperature C Temperature C Temperature C m/sec 16:00 30.6 29.4 25.6 0.52 32.2 31.1 26.7 0.77 32.8 32.2 27.2 0.52 32.8 32.2 27.8 0.52 30.6 30.6 25.0 0.52 31.7 30.6 23.9 1.03 29.4 29.4 25.6 0.26 29.4 29.4 25.0 0.26 27.8 27.8 23.9 0.26 29.4 29.4 25.6 0.52 -115- Table 8.3 Experimental sample data for broiler house at west side position from July 6 to 22, l979. Black Globe Inside Air Wet-Bulb 0 Air Velocity Hour Temperature C Temperature C Temperature C m/sec 7:00 26.0 26.0 22.8 0.26 27.2 27.2 23.9 0.26 26.0 25.0 22.8 0.26 26.0 26.0 23.3 0.26 25.0 23.9 22.2 1.03 26.0 25.0 22.2 0.26 26.7 26.0 23.3 0.26 28.3 27.8 23.3 0.26 9:00 27.2 27.2 23.9 0.26 28.3 27.8 23.3 0.26 34.4 33.3 25.6 0.52 30.0 28.9 25.0 0.26 28.9 28.3 24.4 0.26 28.9 28.3 25.0 0.26 31.7 30.6 26.0 1.03 29.4 28.9 24.4 1.03 29.4 28.9 25.0 0.26 28.3 27.2 23.3 0.26 27.8 27.2 23.9 0.26 28.3 27.8 23.9 0.52 27.8 27.8 24.4 0.26 28.3 27.8 24.4 0.26 11:00 31.1 30.6 26.7 1.03 33.3 32.2 26.7 1.29 32.8 32.2 27.2 0.26 32.8 32.2 26.7 1.03 32.2 31.7 27.2 0.52 ~116- Table 8.3 (continued) Black Globe Inside Air 0 Net-Bulb 0 Air Velocity Hour Temperature C Temperature C Temperature C m/sec 30.6 30.6 25.0 1.54 31.7 30.6 23.9 1.03 31.7 31.7 24.4 1.03 30.6 29.4 24.4 0.77 29.4 29.4 25.0 0.26 31.7 29.4 24.4 1.03 29.4 29.4 25.0 0.77 31.7 30.6 25.0 0.26 13:00 31.1 30.6 26.0 1.03 34.4 33.9 27.8 1.03 34.4 33.3 27.2 0.77 33.9 32.8 27.2 0.77 31.7 31.1 25.0 1.54 32.2 31.7 22.8 1.54 32.2 31.7 25.0 1.03 29.4 29.4 24.4 0.26 32.2 31.7 24.4 0.26 28.3 28.3 23.9 1.03 28.9 28.3 23.9 0.52 30.6 29.4 25.6 0.52 15:00 28.9 28.3 25.0 0.26 32.8 32.2 26.7 0.77 28.3 27.8 23.9 0.77 33.3 32.8 27.8 1.29 31.7 31.7 25.6 1.54 32.2 31.7 23.3 1.03 27.2 26.7 23.3 1.03 29.4 28.9 24.4 1.03 28.3 27.8 23.9 0.26 -117- Table 8.3 (continued) Black Globeo Inside Air 0 Wet-Bulb 0 Air Velocity Hour Temperature C Temperature C Temperature C m/sec 28.3 28.3 25.0 0.26 31.7 31.7 25.0 1.54 17:00 35.0 31.0 26.0 1.03 32.8 31.0 27.2 0.77 33.9 31.7 26.0 1.54 33.9 31.7 23.9 1.54 34.4 31.0 24.4 1.03 34.4 31.0 24.4 0.77 35.0 31.7 25.6 0.77 -118- Table 8.4 Experimental sample data for broiler house at east side position, from July 6 to 22, l979. Black Globe Inside Air Wet-Bulb Air Velocity Hour Temperature C Temperature C Temperature C m/sec 7:00 26.0 26.0 22.8 0.26 28.3 26.7 23.9 0.26 31.7 26.7 23.3 0.26 29.4 28.3 23.3 0.26 33.9 27.2 22.2 0.26 32.2 27.2 22.2 0.26 29.4 27.8 23.9 0.26 35.0 31.7 23.9 0.26 9:00 29.4 28.9 24.4 0.26 28.3 27.2 23.9 0.26 29.4 28.3 23.3 0.77 35.0 27.8 22.2 1.03 31.7 30.0 25.0 0.26 29.4 28.9 25.0 0.26 31.7 31.7 26.0 1.54 30.6 29.4 23.9 1.29 30.6 29.4 25.0 1.03 30.6 28.9 23.9 0.26 29.4 28.3 23.9 0.26 29.4 28.9 23.9 0.26 29.4 28.9 24.4 0.52 29.4 28.9 24.4 0.26 11:00 31.1 30.6 26.7 1.29 31.7 30.6 24.4 0.26 33.9 33.2 26.7 1.55 33.3 32.8 26.7 0.52 33.3 32.8 27.2 1.29 32.8 31.7 26.7 1.03 -ll9- Table 8.4 (continued) Black Globe Inside Air Wet-Bulb Air Velocity Hour Temperature C Temperature C Temperature C m/sec 30.6 29.4 25.0 1.29 31.7 30.6 23.9 1.29 31.7 31.7 24.4 1.29 31.7 29.4 24.4 0.52 29.4 29.4 24.4 0.26 31.7 31.7 22.8 0.52 30.6 29.4 25.0 0.52 31.7 30.6 25.0 0.26 13:00 32.2 31.1 26.0 0.52 31.1 30.6 26.0 1.29 34.4 33.9 27.8 1.29 34.4 33.3 27.2 1.29 33.9 32.8 27.2 1.55 31.7 31.7 25.0 1.55 32.2 31.7 22.8 1.55 31.7 31.7 25.0 1.55 29.4 29.4 25.0 0.26 31.7 31.7 25.0 0.77 29.4 28.9 24.4 1.03 29.4 28.9 24.4 0.77 30.6 29.4 26.0 1.03 15:00 28.9 28.3 24.4 0.26 32.8 32.2 23.9 1.55 28.3 27.8 27.8 0.77 32.8 31.7 25.0 1.55 31.7 31.7 23.9 1.29 31.7 31.7 23.9 1.55 28.3 27.2 24.4 0.26 23.9 28.9 23.9 1.55 -120- Table 8.4 (continued) Black Globe Inside Air Wet-Bulb Air Velocity Hour Temperature C Temperature C Temperature C m/sec 28.3 27.8 25.0 0.26 28.9 28.3 25.6 0.26 31.7 31.7 26.7 0.52 17:00 30.6 30.7 25.6 1.55 31.7 31.7 26.0 2.31 29.4 29.4 23.9 2.31 30.6 30.6 23.9 1.29 28.9 28.9 25.0 0.26 30.6 30.6 25.0 0.52 27.8 27.8 23.9 0.26 28.3 28.3 24.4 1.03 -121- APPENDIX C PREDICTED VALUES FOR THI AND BGHI -122- nAwu ..«1 work Co‘s 3.5» uoap noon w.v» 0.49 u._; a.ma con: oo—c coca u.o~ cohp vow» n;— "oan ..." u.~n o.— w.w «on 9.." —.mn comm o.cn motw ..xm '0 Ann» quJu coun son comm «can mo¢m axe» 2