THE USE OF DOUBLE-FAME WINDOWS FOR UTILIZING SOLAR ENERGY IN SWINE HOUSING Thesis for the Degree of M. S. MICHIGAN STATE COLLEGE Maurice Wayne Brandt I954 ...... THESiS This is to certify that the thesis entitled "The Use of Double-pane I-indows for Utilizing Solar Energy in Swine Housing” presented by Maurice It . Brandt has been accepted towards fulfillment of the requirements for _£°_.§_9__ degree in W «'5 1 Eng inee ring (Mam/y. m arm. Major professor Date September 114, 153-51; 0—169 THE USE OF DOUBLE-FARE WINDOWS FOR UTILIZING SOLAR ENERGY IN SWINE HOUSING 3:7 Maurice Iayne Brandt THESIS Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Agricultural Engineering 1951; TH F95 fir i .1 «-~ u AOKNOWLEDGMHTS The author expresses his sincere appreciation for the counsel, guid- ance. and interest of Dr. James S. Boyd, under whose supervision this work was done. I Be is also deeply indebted to Professor Arthur I. Iarrall. Head of the Department of Agricultural Engineering. Iichigan State College. for his interest in the project. and for assigning the assistantehip without which this program could not have been carried on. Grateful acknowledgment is also due to Dr. J .A. Reefer for his help- ful suggestions and cooperation in the use of the facilities of the col- lege swine farm. Appreciation is expressed to Dr. LI. Carleton, Professor 1‘.J. Brevik and others of the Department of Agricultural Engineering. Itichigan State College. for their helpful advice during the course of the study. The author appreciates the financial support of the Libbey-Owens- l'ord Glass Company and the interest shown in the project by Ir. l. lverett lakin, Director of Yarn Research. The author extends his gratitude to Dr. G.A. Crabh for making avail- able solar radiation and relative humidity data recorded by the Iichigm Hydrologic Research Station, lichigan Agricultural lsperiment Station in cooperation with the Bureau of Plant Industry. Soils. and Agricultural Ingineering of the United States Department of Agriculture. 34445-30 w THE USE OF DOUBLE-Pm WINDOWB FOR UTILIZING SOLAR ENERGY IN SWINE HOUS IHG By laurice Iayne Brandt Al ABS mcr Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER 01' SCIENCE Department of Agricultural Engineering 195It Approved iv MAURICE IAYNE BRANDT ABSTRACT his study was carried out during the sumer of 1953 and the winter of 195” to determine the differences in the environmental conditions be- tween three types of experimental hog houses as compared to a conventional house and the effect they had on the hogs in each house. be three experi- msntal houses were solar orientated on an east-west axis and were of iden- tical construction. in. only difference between the three houses was the mount and type of glass used on the south wall of the structures. One house was equipped with double-pane windows. a second house was equipped with single-pane windows. and a third house was equipped with double- pane windows half the height of the windows in the other two houses. lach house was divided into two pens. The fourth house of conventional con- struction was located on a concrete slab. this house was used as a con- trol for the study and did not contain any windows. Each experimental house contained two lots of four pigs each. These pigs were kept in the houses all the time while those in the conventional house were able to go outdoors at will. it intervals of two weeks they were weighed and the total amount of water and feed consumed for the period was recorded. The average weight of the hogs was about 97 pounds at the beginning of the sumer study. Conditions in the houses during I the smear study were very uncomfortable for the hogs and they were re- moved after six weeks. his average weight of the hogs was about 35 pounds at the beginning of the winter study. They were kept in the houses until the heaviest ones reached a market weight of 200 pounds. MAURICE WAYNE BRANDT The total feeding time was 16 weeks. An automatic potentiometer, was set up to measure and record tem- peratures. The outside temperature and the wet-bulb and dry-bulb tem- peratures inside of each house were recorded. The operation of ventil- ating fans and heat lamps was recorded by means of zh-hour on-and-off recorders. Inter consumption of the hogs was determined by a gage located on the side of the water tank kn each pen and feed consumption was re- corded. Data from the stunner study indicated no advantages in housing hogs in solar orientated houses. The winter study indicated that there was a statistically significant advantage in housing hogs in solar orientated houses having double~pane windows. The investigation should be continued to verify these results. vi TABLE OF CONTENTS INTRODUCTION 0 I I O O I O 0 O O O O O O 0 C O O - O O O O O O O I O 0 History of the Project . . . . . . . . . . . . Description of the Project . . . . . . . . . . Objectives of the Project .. . . . . . . . . . ' Reasons for the Study . . . . . . . . . . . . e The Practicality of Solar Heating of Reg Hous s va E' or H ”mm . . . . . . . . . . . . . . . . . . . . . . . . 801‘, Inangy e e o a o e e o e s e o e e s e o o e o e e o e o o Solar radiation . . . . . . . . . . . . . . . . . . . . . . Factors affecting the amount of solar energy reaching the 'urf‘c. 0‘ ‘h‘ .‘rth e o o e e e o e e e o e o o e e e e e 8°1.r heating Of housa. e e e e o e o o o o o e e o e a e e The transmission of radiation through glass . . . . . . . . The transmission of heat energy and solar radiation through double-panowindews............ Heat losses through glass . . . . . . . . . . . . . . . . . Comparison of single and double-pane windows . . . . . . . . $.1‘r1G‘t1.‘ e e e o o o o o e e o o o o o o o o s o o o e o The lffects of Temperature. Relative Humidity, Air lotion. andSelarRadiatienonSwine ................. The effect of temperature . . . . The effect of relative humidity . The effect of increased air motion The effect of solar radiation . . “Pam m “THO mm! C O . D O I O O C O C O O O I C O C O O C Construction and Equipment . . . . . . . . . . . . . . . . . . . Inl‘rumflnt.‘1nn o e o e e e e e e o e e e e e e e e e o e e e e Procodur. .e e e o o e o e e e e e e o o o e s o o e o e e e e e PmsnTATIon AND ANALYSIS a “TA- . O O O Q 0 C O O I O O O O O O . Part I - Analysis of the Summer Study. . . . . . . . . . . . . . Temperature . . . Relative humidity . Ventilation . . . r..d1n8 trial s e Conclusions . . . an OR 09 0Q Sr¥rfl)*‘h‘ IO 11 18 18 19 at 21 22 22 23 23 32 37 33 33 33 39 39 39 I O O I O 0 I O I O I O I I O O O O O “1 vii Part II - Analysis of the Winter Study . Temperature Relative humidity Ventilation Heat lamps . . . . . . . . frost and moisture condensation Quality of the air . . . . . . . Sun patterns . . . . . IIIding trill o e e e The conventional house Chewing the gates . . Conclusions- . . . . . Part III - Analysis of the the houses '1ntor e e e o e e e a Spring . . . Conclusions . . . . . CONCLUSIONS SUGGESTIONS FOR FUTURE STUD! omens m1: Barons m smsms STUD! or 1951; without APPERDIX.A - The Temperature. Relative Humidity. tion Dots for the Summer Study and Solar in Radia- lnplanation of the relative humidity data for the summer study . Explanation of the temperature and solar radiation data for the summer study APPENDIXLR - The Temperature. Relative Humidity. Solar Radiation 69 59 71 71 73 7h 76 77 78 79 and Ventilation D.t. for th. 'intIr Stn¢y e e e e e o e e o e e e e 90 Explanation of the relative humidity data for the winter study . 91 Explanation of the temperature. solar radiation and ventilation at. for the untor study I I I I I I I I I I I I I I I I I I I 92 Gmsw I I I I I I I I I I I I I I I I O I I I I I I I I I I I I BIBLIOGRAPHY s a e e 0 e e e e e o e e o e e e e e o e o a e e e e 117 118 viii LIST OF fiaBLES Table 1. Summary of the results for the hog feeding trial of the summer study of 1953 . . . . . . . . . . . . . . . “0 Table II. Summary of the results for the hog feeding trial of the winter study of 1953-5M . . . . . . . . . . . 1 . . 59 Figure ligure Figure Figure Figure thurO figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure 9. 10. 11. 12. 13. 1h. 15. 16. 1?. ix LIST OF FIGURES The two eXperimental houses used for the summer study . The three experimental houses used for the winter study, The conventional house located on a concrete slab . . The intensity of solar radiation at different wave length.OOOOoeoeeeeeeeeeeeeeeose Transmission of solar radiation by a single sheet of 81". I I I I I I I I I I I I I I I I I I I I I I I I I Transmission of solar radiation by two sheets of glass . Absorption of solar radiation by a single sheet of glass . . . . . . . . . . . . . . . . . . . . . . . . . Absorption of solar radiation by two sheets of glass ‘ 'hIn thI XL 0! IhI innIr IhIIt IqualI 0.05“. o e e e e e The plan for the framework of the three experimental hon. °. I I I I I I I I I I I I I I I I I I I I 0 I I I I The framework of the houses with the blanket insulation inIIIllId e o e e e e e e e o o e e o e e e o e e e e e The four stages of the construction of the roof and floor panels . . . . . . . . . . . . . . . . . . . . . . A view showing the windows installed and the sun shades. Th. erd ItorIgI box e e e a e o a o e e e o e e e s e a The section of the feeder that is located inside the hula“ I I I I I I I I I I I I I I I I I I I I I I I I The automobile gasoline tank and the type of automatic watersr used in the summer study.. . . . . . . . . . . . The type of automatic waterer used in the winter study and the position of the heat lamp . . . . . . . . . . . A rear view of one of the houses showing the air intakes 2 12 15 15 16 '16 2h 25 25 27 27 28 29 29. and th‘ Imust met throng th. 1.0th e e e e e o o o e 30 Figure Figure Figure Figure Figure thure figure Figure figure Figure Figure Figure 18. 19. 20. 21. 22. 23. 2M. 25. 26. 27. 28. 29. Figure 30. Figure 31. Figure 32 . thure 33- Figure 3“. The electrical wiring system for the three experimental houses and the instrument box . . . . . . . . . . . . . The instrument box for housing the potentiometer, the time clock and the connecting plug . . . . . . . . . . . The placement of the thermocouples in the walls of the 11011803...o.....oo.o............ The placement of the thermocouples in the floor and roof Ofthohoulel.......o............. The box containing the plugs for connecting the thermo- couples in the walls to the potentiometer . . . . . . . The recorder which kept an on-and-off record of the Operation Of the Ventilating fan. e e e e e e e e e e e The maximum.daily temperature in the four test houses from December 15. 1953 to April 6. l95u . . . . . . . . The minimum daily temperature in the four test houses from December 15. 1953 to April 6. 195k . . . . . . . . The mean daily temperature in the four test houses from December 15. 1953 to April 6. 1951; . . . . . . . . The difference between maximum and minimum daily tem- peratures from December 15. 1953 to April 6. 195“ . . . The total amount of solar radiation for each day from December 15. 1953 to April 6. 195% and the normal amount of solar radiation for each day of the same period . . . The distribution of the air as it enters the house through one of the air intakes in the rear wall . . . . The distribution of the air as it moves across the front of the house towards the air intake of the fan . . . . . A typical view on cold mornings showing how the single- pane windows frosted over while the double-pane windows didnotQCoro-I-IIIIIII-I'IIII'IIIIIII The single-pane windows were covered over with frost up to one-eighth inch thick on nights when the temperature outdoors went below 25° F. . . . . . . . . . . . . . . . The double-pane windows never had any frost on.them but moisture did condense on the inside surface . . . . . . The sun pattern in House 0 on January 21. 195M . .p. . . 31 32 3k 3k 35 36 1*3 nu xi5 M7 52 52 5h 55 55 5s Figure 35 . Figure 36 . Figure 37 . Figure 38. Figure 39 . Figure 140 . Figure 1&1 . Figure 142. Figure )43 . mm. Me Ifigure 1&5. Figure ’45 . l'i-g'tiu‘e 1+7. The sun pattern in House D on January 21, 19514 . . . . . The sun pattern in House 0 on February 17. 1951+ . . . . The sun pattern in House D on February 17. 1951+ . . . . The sun pattern in House 0 on March 17. 1951+ . . . . . . The sun pattern in House D on March 17. 19514 . . . . . . The average daily gain per hog for each two week period Ofth0'1nterstweeeseeeeeeeeeeeeee The average daily feed consumption per hog for each two week period of the winter study . . . . . . . . . . . . The amount of feed consumed per pound of gain for each two week period of the winter study . . . . . . . . . . The average daily water consumption per hog for each two week period of the winter study . . . . . . . . . . The average amount of water consumed per pound of gain for each two week period of the winter study . . . . . . A typical sight in House A during the winter study showing how the hogs all huddled together to keep warm . The gate in House 0 was all chewedup . . . . . . . . . The gates in both Houses B and D were only chewed a small mm‘ I I I I I I I I I I I I I I I I I I I I I I I I I 58 58 58 58 58 63 67 68 68 INTBDWOTION History of the Project In 1952 a study was made on the effect of environmental conditions on the growth rate and efficiency of gain of hogs in two different types of swine housing. hiring the study there were variables which could not be controlled or evaluated. It appeared necessary to use smaller houses in which some of these variables could be eliminated and others controlled and evaluated. In 1953 plane were fomlated for construct- ing three identical houses. except for the type and amount of glass used. Deseription of the ProJeet his project was sponsored Jointly by the Iiehigan Agricultural preriment Station and the Libbey-Owens-l'ord Glass Company. Coast rue- tion was started on three experimental houses in April. 1953. Two of the houses were completed in July. 1953 and were put into use during the following month. ihe third house was completed in lovember. 1953. All three houses were used for the winter study starting in December. 1953. The first phase of this project which was a study of the environ- mental conditions in two experimental hog houses differing only in the type of glass used was completed in the sumer of‘l953. Figure 1. Out- side air taperature. wet-bulb and dry-bulb temperatures in the houses. and the mount of ventilation in the houses were recorded. The amount 51 solar radiation and outdoor relative humidity were obtained from the Figure 1. be two experimental houses used for the miller study. Michigan Hydrologic Research station. The second phase of the project eves completed in the winter of 1953-5”. his phase was a study of the environmental conditions in three experimental hog houses differing only :in the type and mount of glass used for windows. he houses used during the winter study are shown in Figure 2. Tnperature. relative huidity. ventilation and solar radiation data were also collected for the winter study. A house of conventional construction and located on a concrete slab. as shown in Figure 3. was used as a control for the studies. Objectives of the Project be objective of this research project was to obtain data which can be used to evaluate the thermal advantages and disadvantages in a given locality for a given type of hog house. has rate of gain in weight and the feeding efficiency of the hogs raised in the houses and outdoors were compared. be water sonsmption of the hogs in the experimental houses " raw...” " J.‘ ' u I 5. 2 ” e __ V , ,I ‘ ," .’ _ 4' '~ p139”: 51 a . 5:. }’ ‘ "' ’ ‘~_" V . ‘ . W- :;__._n,- 1, Figure 2. be three experimental houses used for the winter study. as «Nth. . ‘ - ..... - L , hue." wf‘fl‘rfi; d Figure 3. he conventional house located on a concrete slab. was also compared. An attempt was also made to determine differences in the quality of the air in the houses. Reasons for the Study For the past thirty years there has not been a significant develop- ment in the design of hog houses. Fifty years ago the half monitor de- sign was used extensively for hog houses. The loss of heat through the top windows of this type of house was excessive. The usefulness of the sun's energy was realised at that time but efficient methods of utilisa- tion were not available. As a consequence emphasis shifted to a hog house design with a minim amount of glass area. The data from this study will be useful in the desip of hog houses where solar energy can be utilised with larger areas of glass. According to information attributed to D.S. Soutar (510" of the lorth of Scotland College of Agriculture. 'a happily-housed hog costs far less to fatten than a hog in a hovel." Poor housing may be costing Britain approximately $9.50 more per head to fatten hogs in shabby pens than it costs'to fatten those which were well-housed. The Practicality of Solar Heating of Hog Houses Solar heating of homes was first started in the U.S.A. about 1930. However. up until the present time (1951:) a satisfactory method of uti- lising solar energy to the fullest extent has not been deve10ped. Solar houses have been built which use the principle of large south-facing ‘indows. Fuel savings in these homes have mnounted to 18 to 30 percent “embers in parenthesis refer to the appended bibliography. (57) in some instances while in others, losses up to 16 percent (58) have been reported. This raises the question as to whether or not solar heating of hog houses can be accomplished efficiently. Hog'houses have an advantage in that a constant temperature does not have to be maintained. although temperatures between 50° and 70° F. are desirable. Therefore. the advantage of using solar energy for heating hog houses should be greater than for heating homes. The purpose of a solar type hog house is to obtainumore efficient utilisation of the sun's energy for light and heat. This can be done by using large areas of glass on the south side of the houses. The use of double-pane windows is necessary to eliminate excessive outward heat transfer through the glass. The maximum gain from solar energy is entirely independent of the outside temperature at any'particular latitude. However. the amount of solar energy and outside temperature vary in relation to the latitude. Heating with solar energy will have the least not effect where heat trans- mission losses through the glass are greatest. that is, where the outside temperatures are low. Solar heating of hog houses will have an advantage in this respect because the temperature difference between the outside and inside temperatures will be less than the temperature difference in a.home. Therefore. transmission losses will be less in.a hog house while solar gain remains constant all other conditions being the same. Solar heating has the greatest advantage in relatively cold climates where there is a large amount of solar radiation available at the earth's surface. In areas which have very cold weather the advantage of solar heating will be decreased and.mmy even be eliminated entirely. Solar construction will be the most economical in a cool climate where there is a large quantity of solar radiation available. Solaréheating of hog houses creates a complex problem. The energy gain depends upon the transmissivity, the absorptivity and the reflectivity of the glass. It is a function of geOgraphical location and climate. the outside air temperature during the winter months. the amount of solar energy and the time of day. Other factors such as wind velocity, type of glass. thermal conductance of the walls of the structure. and amount of ventilation required and the heat produced by the animals also play an important part in the problem» All of these factors must be considered in determining the practicability of using the solar principle for heat- ing of a hog house. The hog houses that were constructed should not only permit more effective utilisation of solar energy. but should accomplish the short- time storage of the energy for use during later hours after the sun sets. They were designed both to capture a maximum quantity of solar radiation and to utilise it for heating purposes. The affect of solar radiation in reducing the heating requirements for the hog houses should be the same as far as all foams of construction other than the glass are concerned. Both single and double-pane windows have a relatively small effect in intercepting solar radiation through the glass. Approximately ten percent of the solar radiation incident upon each pane of glass may be intercepted. This means that approximately 90 percent of the solar radiation incident on the single-pane windows should pass through. while approximately 80 percent will pass through the doubledpane windows. Therefore. it would be expected that the effect of solar radiation should be greater in the single-pane houses. How- ever, a double-pane window is a better heat trap than a single-pane win- dow. Consequently. while slightly less solar radiation will come through a double-pane window. considerably less heat energy can get out by con- duction so the net heat gain is greater with double-pane windows. RFVIEI 0F LITERATURE Solar Energy §olar radiatigg. Solar energy is emitted by the radiating isothermal layer or photoephere of the sun which has a temperature of 60000 C. ac- cording to Koller (‘00). Outside the earth's atmosphere at the mean so— lar distance which is the arithnetical mean distance between the greatest and least distances of the earth from the sun. the intensity of solar radiation is 1.5 horsepower per square yard. Approximately two thirds of this energy reaches the surface of the earth after being absorbed. reflected and scattered by the atmosphere. The intensity of solar radia- tion is primarily a function of the height of the sun above the horison. The intensity is also affected to a lesser extent by the distance of the earth from the sun and the clearness of the atmosphere. The amount of radiation which the sun emits varies as much as five percent. Hienton. liant and Brown (20) state that from one to five percent of the sun's energy reaching the surface of the earth is in the ultra- violet region (2900 A. to 3800 A). Approximately 1‘0 percent of the sun's energy reaching the surface of the earth is in the infrared region (7600 A. to 150.000 A.) which is readily absorbed by many objects. This absorp- tion or heating effect makes infrared radiation very useful for solar mating e Factors affectng the amount of solar eneggy reaching the surfacg gf thg garth. Pamelee (It?) reports that the loss of direct solar radi-' ation in the atmosphere is caused by: (l) Atmospheric scattering by air molecules. water vapor and dust (approximately 16 percent) and (2) Atmos- pheric absorption by oxygen. osone. water vapor. carbon dioxide and dust (approximately 12 percent). Laurens (hi) states that the intensity of solar radiation at the earth's surface varies chiefly according to geographical position. the season of the year and the time of day. The amount of radiation at the earth's surface is also dependent upon momentary changes in atmospheric transparency. cloudiness. dustiness and humidity. Three general factors therefore determine to a great extent the quantity of solar radiation received at the earth's surface. namely. altitude above sea level. the average degree of cloudiness. and the average purity of the atmosphere. The depletion of solar radiation due to the longer atmospheric path in winter is approximately offset by the shorter distance between the sun and the earth according to Hutchinson (30). The sea level intensity is almost the same for all seasons of the year. The scattering effect of dust and water vapor in the atmosphere in winter is greater since the winter solar altitude is less. Therefore. the amount of diffuse or sky radiation is considerably greater at sea level in the winter. Sinner sky radiation is about one half as reach as that in the winter. A statistical analysis by Olough (12) indicates: (1) that fluctua- tions in daily. monthly. and yearly mean values of the solar constant are so dependent on the transparency of the atmosphere that they cannot be regarded as even approximate values of changes in solar intensity. and (2) that as short-interval changes in the solar constant become smaller. the dryer. clearer and shorter the air mass through which solar radiation met pass. 10. Frits (16) States that the depletion of solar radiation by the at- mosphere in the Great Lakes region amounts to 20 to 30 percent of the radiation through a clean atmosphere in the winter. while in the summer it is about 10 to 15 percent. his is caused mainly by large industrial activity in the whole area together with increased hasiness due to the lakes. Radiation during cloudless days in the United States decreases in December to about 20 percent of the mar value in the north. and to about 50 percent of the summer value in the south. gglar heating of hougel. Studies made by Hutchinson (28. 30) at Lafayette. Indiana indicate that the performance of a solar house depends upon the construction of the house. the range of outside temperatures. the amount of direct solar radiation and the quantity and quality of in- direct or sky radiation received on days when the sun is obscured. he results of a nine week study using two identical houses. except for the areas of glass in each house. show an average reduction of nine percent in the heating requirements for the solar house as compared with the heating requiruaents for the orthodox house. However. the solar gain in I house of solar construction should not be attributed entirely to the construction since an appreciable amount of the heating effect would be realised even if the glass area of the house was no greater than that in in orthedox house. An analysis of double-pane windows in south walls (30) shows that the available gain from solar radiation in most cities of the United States is more than enough to offset the excess transmission losses through the larger windows. 11. The transmission of radiation throygh glass. Windows differ from most structural elements of buildings in that the principal component. glass. is used in a thin sheet which. in itself. affords very little resistance to heat flow. Glass also transmits large quantities of solar radiation. Miller and Black (1th) have found that glass is transparent to solar energy in the visible region but is opaque to all other wave lengths except a narrow band of the longest of the ultraviolet and the shortest of the infrared. The ultraviolet and infrared radiation that is transmitted to some extent is cut off entirely by thick glass and even relatively thin glass cuts off a large part of it. The amount of radiation transmitted is selective for different wave lengths and there- fore is not uniform and it never reaches 100 percent. as shown in figure 14. Approximately five percent of the incident visible light and as much as 19 percent of the invisible infrared radiation is reflected from each surface of the glass. Glass does not tranmit any appreciable amount of long wave radiation. his characteristic of radiant energy makes possi- ble the use of solar radiation for heating houses. The short waves of solar infrared radiation pass freely throng: the glass. are absorbed within the house and are reradiated as low temperature long wave length rays which are trapped within the house. Miller and Black (M) also fotmd that only about 0.0523 percent of low temeratue radiation is transmitted by glass. An investigation made using a test house with south-facing windows (2h) lists several sources of heat entering and leaving a house through the windows. Solar and sky radiation impinges on the surface of the Glass at various angles throughout the day. Part of this energy passes émmm. rmaocmég vac #ch do .08 .E< .mcofi £02m .>J ecu $2.22 <5 «£32 26; Emcmtfi 6 c2868 .28 do bacon; of .c 959“; mzomoi Z_ Ibozuq m><>> n v m N _ O __ i _q o m _ _ _ l. m _ 3 _ _ N W _ _ _ B _ -_- _ a o M 3.3-3.- ---- , -- L, 3-34!- _ o _ . m _ _ O _ 5:: 5.5 843 main _ _ _ .3 _ >mm OMPEZmzn‘mP .Eda MI... _ _ W _ * _ _ 10.. .3 --.--33--- .1- - ; : 4 - :1 -, I J... . _.-- - - -MI1 08 V H _, N A D H. a a _ u _ we a . m . . V 8 V . a _ B 1 M _ a a m. 3 m P: .- - - - - M - - - g- - - 3- - z-Ti- - - lei-,3. + , B 1 00m «cu. _ m . _ _. W a n _ _ .w . d /..V. _ a _ a _ s _ u _ a _ _ w - - 4-; - - - -- - - .. --_- 4-3-8. « _ m a _ 0 a _ _ _ _ .m. a _ a _ _ .- w h w _ _ con m (a 13. directly through the glass into the room. part of it is reflected and the remaining part is absorbed by the glass. 'nie absorbed energy raises the temperature of the glass so that heat is transferred from both surfaces of the glass to the surrounding air. The temperature of the glass and the air determine the division of heat energy. Heat transfer also takes place between the inside and outside air through the glass depending up- on the temperature difference. Indications are that the increased ab- sorption caused by increasing the angle of incidence of the sun's rays is due to the greater thickness of the path of the rays rather than from reflection. Reflection is not an important factor in heat transfer through a window by solar radiation. Measurements made of solar heat transmission through glass (51) show that the transmittance of normal incident radiation through different glasses may vary as much as 10 percent. These differences are believed to be caused by atmospheric conditions that change the energy distribu- tion of the solar spectrum. Other factors such as wind velocity. low temperature radiation exchange between surrounding buildings and the glass. reflected radiation from the ground and nearby buildings. and radiation exchange between the glass and the atmosphere also affect the heat trans- mitted by or conducted through the glass. In an analysis of heat flow through glass windows exposed to solar radiation. Pamelee (it?) shows that the important preperties of glass are the index of refraction and the absorptivity of the glass. These two properties are functions of the wavelength of the incident radiation. Specific heat. specific weight. and thermal conductivity are of secondary importance. ihe chemical constituents of glass determine its absorption 1%. characteristics. According to Parmelee (M7) ferric oxide is strongly absorbent in the ultraviolet region and ferrous oxide in the infrared region. various degrees of absorption can‘be obtained by varying the quantities of these two compounds. Pamelee (147) has also studied the effect of the angle of incidence of the sun's rays on the transmission and absorption of glass. The re- sults of the investigation are shown in Figures 5 through 8. The figures show the transmission and absorption expressed in.percentages as func- tions of both the angle of incidence and the absorption characteristic. IL. of the glass. IL is the product of the absorption coefficient. K. and the thickness of the glass. L. The term is dimensionless. since I is expressed as absorption-per inch and L is in inches. The percentage of absorption for any type of glass is seen in Figure 7 to be practically constant between the incident angles of O and 70 degrees. Figure 8 gives the fractions absorbed for one particular case. that in which the inner glass has a KL of 0.05”. The outer glass may have any character- istic. In a study with single-pane windows. Boughtan and Outberlet (2H) found that window glass placed so that the sun's rays must pass through it before impinging on another surface. reduces the heat absorption of that surface by from 9 to 17 percent when the rays are nonmal to both. the glass and the surface. For smaller angles the glass retards a greater percent of the radiant energy. The effect of the angle of incidence on the absorption of radiant energy was also studied and they found that the langer the angle of incidence. the greater the reflection and the lower the intensity of impingment of radiation per unit area of the surface. . { i [ Z 9 . U) 5 ANGLE OF INCIDENCE 4 0° E 40" 50° F / 10: ___.._____. 2 80 U U E- l \ W ft.“ 5 \ ; \a 00 ' 025 0.50 0.75 I.00 |.25 l.50 l.75 KL OF GLASS Figure 5. Transmission of solar radiation by a single sheet of glass. (G.V. Pormelee, Trans. Am Soc. of Heat. and Vent. Engrs., l945.) (M _ \ i ‘ l i 0 O _ .fikgl_____a - 5 . g ‘ 5 ANGLE OF INCIDENCE E I ‘35. 60° 40 I / 70° "'" I- 90° 3 . 2 \~\_ 3 2° \ ” “‘ cz: . b i \JWK: 00 0.25 0.50 075 I00 l.25 L50 l.75 SUM OF KL FOR THE COMBINATION Figure 6. Transmission of solar radiation by two sheets of glass. (G.V. Pormelee, Trans. Am. Soc. of Heat. and Vent. Engrs., l945.) l6. I00 30 - .. ___..7.- ANGLE 0r INCIDENCE %/ 0° . Q 2%.}. / . g 60 M —“—“*'_"‘W “‘i—’ 80.34 m \ CD 4 /)/ I'- g 40 - /.___.___.-_-__IM_ -— 3L _ __._. h? if 20.—____ e--- _— .——-——-—I»A——— _ —_ _-— -___._J-_..-_.— .— .. O . 0 0.25 0.50 0.75 I.00 l.25 I50 L75 KL OF GLASS Figure 7. Absorption of solar radiation by a single sheet of glass. (G.V. Pormelee. Trans. Am. Soc. of Heat. and Vent. Engrs., l945.) ANGLE OF INCIDENCE £7 00 o 52.32%” 3 6° ““* aorT‘j fly 9 % E 40 L-.. - -. __---.+--—.—- .—-~.I-~»--—« ——-—-~L~—-—-~-—-——+—— -~-— Lu 0 0: Lu 0. 2° ABSORPTION ' av ““ ”_‘*’V:.T'”“ THE INNER GLASS /( 0' 0 _ / 0 0.25 0.50 0.75 I.00 L25 L50 7775 KL OF THE OUTSIDE GLASS Figure 8. Absorption of solar radiation by two sheets of glass When the KL 0f the inner sheet equols 0.054. Trans. Am. Soc. of Heat. and Vent. Engrs.. l945.) (G.V. Pormelee, fall: thro rite of; 1H. “61 17. This is represented by Q = H sin It. where Q is the intensity of radiation falling on the surface at an angle 0 with the surface. and H is the inten- sity of radiation on the same surface normal to the direction of radiation. In their work with shaded windows. Houghten. Gutberlet. and Black- shaw (25) showed that five percent of the solar radiation transmitted through a bare window was transmitted throw a window completely shaded with a canvass hung directly in front of the window and 28 percent through an awning. A standard window shade fully drawn on the inside of the win- dow truismitted 53 percent while the same shade outside transmitted only 30 percent. Hutchinson (30) reports that the quantity of solar energy transmitted through a south exposed window on an average sunrw day in winter is con- siderably more than that received throudi the same window on an average sunny day in the simmer. One reason for this is that there are more hours of possible sunshine in a south-exposed window in winter than in the sun- mer. If the sun is shining. south wall irradiation is possible on the average. for 142 percent of the time during the seven month heating sea- son but only for 37 percent of the time during the three summer months. Another reason for this increase is the fact that the sun is closer to the horizon and as a result the rays strike the window more nearly at right angles. A third reason for this increase is that more than twice as much solar heat enters a south window during a clear winter day than enters during a clear sumer day. If the window has a solar designed roof overhang the reception of solar radiation during a winter day will be almost three times as great as during a comparable average summer day. 18. The transmission of heat engggy and solar rggiatiggrthrough doublg- page windowg. Results of tests on the transmission of heat through dou- ble-pane windows (10) indicate that double-panes with a one~quarter inch air space reduce heat losses by about No percent compared with the losses through single-panes under the same conditions. The rate of heat trans- fer decreased as the air space was increased up to three-sights of an inch. variations in both solar and sky radiation distribution affect the transmittance of doubleepane windows according to Parmelee and Aubele (”8). This causes the transmittance of double-panes to be equal or greater than the product of the transmittances of the two panes separately. The trans- mittance was about five percent greater for standard double-pane glass and about 20 percent greater for standard single-pane glass plus a heat-- absorbing glass. -A heat-absorbing window outside of a regular single- pane window reduces the transmitted solar radiation considerably. Parmelee (A?) has found that the order in which the sheets of a dour ble-pane window are placed.has no bearing on either the amount of solar enengy transmitted or the amount absorbed by the combination even if they are of different characteristics. However. the heat flow frdm the indoor surface of double-panes is complicated by the fact that each pane of glass absorbs ariifferent percentage of the incident radiation. Heat losseg thrgggh glgss. The chief factors which govern the heat flow through glass windows. as stated by Pamelee and Aubele ('49). are the indoor and outdoor surface conductances and the conductance of the air space or spaces of multiple windows. The indoor surface conductance amounts to about 7k percent ef the total thermal resistance and the 1:9 . outdoor surface conductance amounts to about 21+ percent for a single- pane window. The thermal resistance of the glass accounts for only two percent. They also state that part of the heat loss from outdoor glass sur- faces is due to nocturnal radiation. 'niis radiation exchange between the glass and the atmosphere causes a cooling effect since the incoming low temperature radiation frmn the sky is insufficient to balance the outgoing radiation from the glass surface. During the day this cooling effect is unnoticeable because short wave solar radiation more than coun- terbalances the effect. in increase in wind velocity increases the heat flow through windows by increasing the outside film coefficient according to Carr. Killer. and Shore (ll). The increase in wind velocity causes a smaller increase in heat flow through a double-pane window than through a single-pane window because the outside film coefficient is a smaller portion of the overall coefficient for the entire window. Iind velocities beyond 8 miles per hour do not increase the heat flow through glass windows appreciably. Omrisgn 9f siglg and $92“ng windowg. A stuchr by Carr. Killer. and Shore (11) revealed that a double-pane house required from 70 to 80 percent as much heat as a single-pane house of identical construction. mess figures were affected somewhat by wind velocity, temperature diff- erence and sun intensity. ihe average temperature of the indoor surface of the single-pane windows was about half-way between the inside and the outside temperatures when there was little or no sunshine and wind. The teqerature of the indoor surface of the double-wane windows was about one-quarter of the way between the inside and outside temperatures under the same conditions. Therefore. the occupants of a doubleopane house will feel more comfortable than those in a singledpane house under conditions of identical inside air temperatures. This also means that frost will form more readin on the inside surface of the glass of the single-pane house. §glarigstiop. Solarisation is the result of photochemical stabili- sation in.glass due to exposure to radiation from.the sun. Laurens (H1) states that transmission of ultraviolet radiation by ordinary window glass is decreased by the effect of solarisation. It is caused by the presence of iron in the glass. It takes place rather rapidly at first. then the rate decreases as the exposure is continued until all of the chemically active material has combined. Solarisation.is attributed to the reoxida- tion of ferrous to ferric oxide. It causes coloration and spots to devel- op in the glass.. The magnitude of the effect depends upon the kind of glass. the temperature. the time. the wavelength. and the intensity of exposure. The Effects of Temperature. Relative Humidity. Air lotion. and Solar Radiation on swine The design of solar hog houses requires a knowledge of the heat and lloisture losses from swine as well as environmental requirements. These factors are all affected by weight. age. and feed consumption of the swine. i scientifically designed.hog house utilises animal heat to help maintain building temperature; while at the same time. providing adequate ventila- tion to remove products of respiration (especially water vapor). to con- trol relative humidity and aid in maintaining health and sanitation. 21. The effect of temperature. A study of the effect of ambient tem- pereture on swine (19) revealed that fattening hogs weigiing about 200 pounds reach a peak in their average daily growth rate at about 60° 1‘. Pigs that weighed about 100 pounds reached a peak at about 70° 1'. Both below and above these temperatures efficient utilisation of feed declined. High ambient temperatures cause the average daily gain to drop more read- ily than feed consumption. and therefore. the amount of feed required to produce a certain gain increases rapidly. his is due to the fact that as ambient temperature rises it becomes harder for a hog to lose heat by conduction. radiation. and convection. has the animal must rely more heavily on evaporation. it an ambient temperature of 100° F. virtually all of its heat is lost by evaporation. A hog cuts down on feed consup- tion in order to maintain a normal body temperature. Howover. if it is unable to dissipate excess heat. body temperatures rises. Iitchell and Kelly (’45) suggest that temperatures in a farrowing house should not be lower than 50' to 55. r. Somewhat lower temperatures are permissible for fattening hogs because of their higher level of nutrition. However. temperatures near freesing should be avoided in an case. Physical regulation of the body tanperature of a hog is not sufficient above a temperature of 79° 1'. he desirable envirounental temperature for an average hog is about 68° F. and varies with the level of nutrition. being lower for large hogs. h! gfgct gf relgtive hmifltz. for hogs weighing over 200 pounds. Heitman and Hughes (18) have found that only their respiration rate in- creases when the relative humidity is increased except at high temperatures union their body temperature also increases slightly. at high temperatures and low relative humidities. hogs do not become distressed. However. as the relative humidity is increased from about 30 to 90 percent the respira- tion rate more than doubles and body temperature increases from two to three degrees. The effect of inggggggd git motion. Heitman and Hughes (18) also report that at high temperatures an increase in air motion'will lower the respiration rate and body temperature of a hog if he is wet. However. if the hog is dry an increase in air'motion is of no benefit. This is to be expected of a non-sweating hog when the air temperature is higher than his surface temperature. Th3 gffggt gf sglar rpdiatigg. Information is not available on the effect of solar radiation upon swine other than he fact that infrared raditien exhibits a heating effect upon man and animals (20). However. Abbott (1) states that a narrow band of rays in the extreme ultravielet region is necessary for the good.heslth of growing chickens. This group of rays is cut off by glass. APPARATUS AND METHODOLOGY Construction and Equipment The experimental hog houses were constructed according to the plan shown in Figure 9. The only difference in the three houses was in the type and amount of glass installed in the removable window frames. Two of the houses were completed in the summer of 1953 and the third house was finished in the following fall. ‘ The walls of the houses were constructed of 2' x h“ studs 16 inches on center and insulated with one-inch blankets of balsam wool. as shown in Figure 10. Both surfaces were covered with one-quarter inch exterior plywood. The roofs and floors were built as shown in figure 11. Strips l" x 3' were nailed and.g1ued.to three-sights inch exterior plywood sheets with.waterproof glue. i.vapor barrier of to pound roofing felt was placed between the ribs. Two and one-half inches of rock wool insulation was then placed on top of the \epor barrier and another sheet of three-sights inch exterior plywood was glued and nailed to the ribs so that both sides were covered. These prefabricated panels were then nailed into position with the vapor barrier towards the inside of the structure. Caulking compound was placed around the edges of both the roofs and floors to pre- vent water leakage and air infiltrationc The floor panels were placed on k” x 6‘ skids to facilitate moving. 21+. menses 8:58:83 8...: 2: he {0225: 9: .6.— coa 2:. .m 2:9“. 25. Figure 10. The framework of the houses with the blanket insulation installed. figure 11. The four stages of the construction of the roof and floor panels. 26. A 2" x 6" post was placed in the middle of each house. This post supports the ventilating fan and air duct. a shelf for the necessary in- struments. and two gates which divide the house into two pens approxi- mately 7' x 8'. The doors of each house were made of two-inch lumber. covered with one-quarter inch exterior plywood. and filled with rock wool insulation. A vapor barrier was placed under the inside sheet of plywood. Later all the doors were converted to dutch doors. by cutting them in half hori- sontally. no window frames were made of two-inch framing lumber. The glass windows are held in place by 1" x 1" strips and glasing compound. The total glass area of the houses with full sise windows is approximately 38 square feet. This is equivalent to 36 percent of the floor area. One house has double-pane windows and the other has single-pane windows. The third house has double-pane windows half as high as the full sise windows with an area of 18 percent of the floor area. A view of the installed windows is shown in Figure 12. me sun shades were made of sheets of exterior plywood and are also shown in Figure l2. The adjustable supports allow the shades to be changed as desired. The shades were removed during the winter study ex- cept for the last two weeks in late March and early April when the tem- peratures inside the houses became too high. A self feeder and an automatic waterer were installed in each pen. Both the feeder and the waterer can be filled from outside. The feeder has a storage box on the outside of the building as shown in Figure 13. 'hich can be emptied from the bottom if necessary. his part of the feeder 27. R; 4, air; V Figure 12. A view showing the windows installed and the sun shades. 28. that is inside of the building is shown in Figure 1h. The adjustable plate shown is on hinges and is attached to a heavy wire frame which agi- tates the feed in the storage box so that it will keep moving down with- out bridging. The watering system consists of an automobile gasoline tank which holds approximately 17 gallons and an automatic waterer as shown in Figures 15 and 16. The waterer on the left permitted excessive spillage and was replaced by the type shown on the right. To insure against freezing the water. 250-watt infrared heat lamps were placed above each waterer during the winter study as shown in Figure 16. A six volt transformer was used to provide a control circuit for turning on the heat lamps. One thermostat in the house with single-pane windows controlled the operation of the heat lamps in that house and a‘ relay switch was located in each of the other two houses. The thematat would turn on the heat lamps in the single-pane house while at the same Figure in. no section of the feeder that is located inside the buildings. 29. Figure 15. The autombile gas- Figure 16. no type of automa- olins tank and the type of auto- tic waterer used in the winter matic waterer used in the manner study and the position of the study. heat lamp. time it would energies the six volt transformer which would close the relay switch and turn on the heat lamps in the other two houses. Ventilation for each house was provided by a centrifugal fan with .11 air (low rate of approximately 60-75 cubic feet per minute. The fans OIhaust the air through the roof as shown in figure 17. The air intakes “to first installed above the doors but were later moved to the back wall. rigure 17, to permit better circulation of the .air. The total area of tho air intakes was 30 square inches. mring the sumer study each fan “a controlled by a separate thermostat. However. during the winter study 30. figure 17. A rear view of one of the houses show- ing the air intakes and the exhaust duct through the roof. all the fans were controlled by the same thermostat located in the house with single-pans windows. its electrical wiring system for the three houses and the instru- ment box is shown in l'igure 18. The system is divided into four cir- cuits so that each house and the instrument box all have a separate cir- cuit. However, there are two additional circuits cannon to all three houses which permits the use of one control for regulating the ventilat— ing fans or the heat lamps. three drains were provided in each house at the beginning of the winter study to eliminate the accumulation of water and to help keep the litter dry. n1. houses were sloped slightly so that the water would run tewards the drains. 31. Figure [8. The electricot wiring system for the three exper— imentol houses and the instrument box. VTi r_u.._ _. _____ L___I CF r r—-- l L___ I PFZ : ~ Ian ”5 l W /220 volts : i—KL HTZ ' I I CD bib—‘— Tc I z 34 h r E,_/i:2 7“, I FUSE _:___1I Box ”IE I I I I I ' k l,__f _____ I L__..__ I I I l I {_ _____ t __ __ *INSTRUMENT BOX LEGEND ©~LAMP HOLDER CF - CENTRIFUGAL FAN 4 i-‘RECEPTACLE PF - PROPELLER FAN -SIX v0I_T TRANSFORMER HT - t-EATING THERMOSTAT —--GROUND WIRE VT- VENTILATING THERMOSTAT QD-CONVENIENCE OUTLET Rs - RELAY SWITCH i. Disconnected during the winter study. 2. Added before the summer study of l954. 32. Instrumentation The eight point Brown recording potentiometer used previously for the project was used for both summer and winter studies. The time con- trol for the potentiometer as described by Hinkle (21) was also used. This made it possible to take an hourly temperature record of eight thermocouples . The potentiometer, the time clock. and the plug for connecting the thermocouple wire to the potentiometer were all housed in an instrument box shown in Figure 19. This box was thoroughly insulated and heated with two electric light bulbs to insure against damage to the standard cell in the potentiometer. The thermocouple wires were suspended from a pole to the potentiometer (Figure 2) from each house. The thermocouples were made by a method similar to the method used T‘ t Figure 19. The instrument box forvhousing the potentiometer. the time clock and the connect— ing plug. 33- by Hinkle (21). A comon constantan wire was used for each set of ther- mocouples. During the summer study the eight thermocouples were used as follows: one was placed underneath the instrument box to record the out- side temperature; two were placed in the conventional hog house at heights of three feet and five feet; three were placed in the hog house with full». sise double-pens windows. one for dry-bulb temperature and two for wet- hulb temperatures; and two were placed in the hog house with full-sise single-pane windows. one for wet-bulb and one for dry-bulb tenmerature. During the winter study the placement of the thermocouples was the same except that the two previously used in the conventional hog house were used in the third house for wet-bulb and dry-bulb temperatures. The thermocouples in the houses were all lecated about five feet above the floor. . At the time of building the first two houses "-2 thermocouples were placed in the walls. roof. and floor of each house. A sectional view of the placement of these thermocouples is shown in Figures 20 and 21. The thermocouples are numbered from one through forty-two. the lowest number of each set being towards the inside of the building. The thermocouples were connected to plugs in a small box on the end of each house. as shown in Figure 22. in order that they could be connected to the potentiometer. one or two sets at a time. The numbers and location of the thermocouples are indicated in the box. Relative humidity measurement was also accomplished with the use of thermocouples. The relative humidity unit used was very similar to that used by Hinkle (21). However. a fan was not used to provide air move- ment across the wet bulbs since it was found that air movement was 51$. Figure 20. The placement of the thermo- couples in the walls of tne houses. a““‘\‘\\\\\\" } ‘ ‘\\\\\\\\\\“\' Figure 2|. The placement of the thermo- couples in the floor and roof of the houses. LOOSE FILL INSULATION 35. ligure 22. The box containing the plugs for connecting the thermocouples in the walls to the potentiometer. unnecessary for accurate results. The relatiVe humidity units were placed on a shelf in the center of each house approximately five feet above the floor. The operation of the ventilating fans and the'heat lamps was mea- sured by a 'Thmpscribe' recorder shown in Figure 23. This instrument kept an on-and-off record for a 2% hour period. They were wired in parallel with the thermostats which controlled the operation of the ven- tilating fans and the heat lamps. During a period of three weeks at the beginning of the winter study a Brown two pen dial temperature recorder was used to record the opera- 36. figure 23. the recorder which kept an on—and-off record of the operation of the ventilating fans. tion of the ventilating fans and the heat lamps. One thermometer bulb was placed next to a 25 watt electric bulb which turned on when the fans were on and the other was placed under a heat lamp. Therefore. when-A» over either lamp was turned on the temperature of the corresponding thor- mometer bulb went up which in turn was recorded on the chart. The recorder was unsatisfactory because it required a seven day chart which did not , permit accurate recording of the time of operation. As a result. no accurate record of the operation of the ventilating fans was available for the first three weeks of the winter study. At the beginning of the winter study there were long periods of time when the thermostat did not call for ventilation. During these per riods there was a considerable buildup of moisture and amnia fumes in the houses. In order to eliminate this situation a time clock was in- stalled which turned on the ventilating fans for a desired period of time. 37- once every half hour even if the thermostat did not call for ventila- tion. Procedure At the beginning of each study the hogs for each lot were selected at random. Following this some of the hogs were moved to other lots so that there would be more uniformity between the hogs in each lot with re- gard to their weight. sex. and breed. The feed ration fed to the hogs was the some for all the lets. it intervals of two weeks the hogs were weighed to determine their progress. The total amount of feed and water consumed for the two week period was determined at the time of weighing. bed and water were available at all times. Ihenever feed or water sup- plies were low the necessary amount was added and recorded. he houses were cleaned and bedded every morning. n1. operation of the instruments was checked daily and necessary changes such as new charts. additional ink or water for the wet-bulbs. were made and all irregular conditions recorded. The hourly temperature data was plotted on weekly charts along with solar radiation data re- corded at the lichigan Wdrolgic Research Project. The operation of the ventilating fans was also indicated on the weekly charts. The wet- bulb temperature data was converted to relative humidity readings and also plotted on weekly charts. laxinnm. minimum. and mean daily tem- peratures were plotted on charts that covered the whole 16 week period of the winter study. lardmn daily variation in temperature and total daily solar radiation were also plotted on similar charts for the winter Itudy. Rate of gain and water and feed consumption data for the hogs was computed and plotted. 38. PRESENTATION AND ANALYSIS OF DATA In the following discussion the four types of housing used in both the sumer and winter studies are referred to as: House A, the conven- tional house on the concrete slab; House B. the house with double-pane windows; House 6. the house with single-pans windows; and House D. the house with double-pane windows half as high as the other windows. The hogs in House A were used as controls for the studios. Part I - Analysis of the Sumner Study he smer study started on July 214. 1953. but due to a difficulty with the recording potentiometer correct temperature recordings were not available until August 3, 1953. The study was discontinued on September 2. 1953 when it was determined that sufficient data was available so that continuation of the study was unwarranted. The temperature. relative humidity and solar radiation data for the sumer study are shown in Appendix A. The missing data on August 26 and 27 was caused by a failure of the printing mechanism of the potentiometer. The temperatures recorded in House A were essentially the some as the outside temperatures. Appendix A. and were not plotted separately. Temperature. he difference between the inside temperatures in House B and that in House 0 was not significant. However, there were slight temperature differences for short periods of time but a definite trend was not noticeable. 39. Relative humidity. The relative humidity in House A and House B was not appreciably different throughout the summer study. However. on a few occasions there was an appreciable difference in the relative humidity readings. This was due to the improper functioning of the wet- bulb. The main factors contributing to the high relative humidity were the large amounts of water spilled from the waterer onto the floor and insufficient ventilation. Vgntilation. 'me ventilating fans in both House B and House 0 ran almost continuously throughout the entire length of the summer study. They stopped for short periods of time on five occasions in both houses. Observations made during the sumer study indicated that it was too warm and humid in both houses. Nearly every morning there was condensa- tion on all the windows. ‘mese conditions were caused by inadequate ventilation and circulation. It was very apparent that a good ventilat- ing system was necessary to maintain comfortable conditions. legging trial. The results for the feeding trial of the mar study are compared in Table I. The water consumption data was not reliable be- cause large amounts of water were spilled on the floor by the hogs. later consMption data was not obtained for the hogs in House A. The results from the sumer study show very little difference in the rate of growth and the feed consumed per pound of gain between the hogs in House B and House C. fibers was however, appreciable difference between the hogs in Houses 3 and C and the hogs in House A. The hogs in House A made slightly better average daily gains and they made greater gains per pound of feed consumed. SUMMARY OF THE RESULTS FOR THE HOG FEEDING TRIAL OF THE SUMMER STUDY OF 195} TABLE I Treatment House A House B House 0 lumber of pigs 16 (in two lots) 8 8 Average initial 98.2 95.8 95-7 weight in pounds Average final 171.1 155.5 158.“ weight in pounds Average daily 1.9 1.6 1.? gain in pounds Pbunds of feed 3.7 9.2 3.9 consumed per pound of gain Total amount of -- 900.0 825.0 water consumed in gallons 1:1, Conclusions. The results from the susmer study indicate no apparent advantage in housing swine in a solar orientated house with large areas of double-pane windows. However. the conditions under which the study was made did not use the double-pane windows to full advantage although they were completely shaded. his can be corrected by improved ventila- tion or by opening the upper parts of the dutch doors at night and closing them during the day in order to maintain lower inside temperatures. The lower rates of gain for the hogs in House B and c as compared to the hogs in House A can be attributed to poorer living conditions re- sulting from higher temperature and relative husidity in Houses 3 and C. Table I. These conditions can both be traced back to improper ventilation. The houses were entered for short periods of time each day for pur- poses of cleaning and to check the operation of the ventilating fans and the wet-bulb apparatus. Part II - Analysis of the Iinter Study The winter study started on December 15. 1953. continued for a six- teen week period and ended on April 6. 195% Several of the hogs had reach- ed market weight by the end of the period. The winter study was an inves- tigation of the effect of two types of window glass on the rate and effi- ciency of gain of hogs and the effect upon their environment. House A. House B. and House 0 were again used for the winter study. In addition. House D. the house with double-pane windows only half as high as the other windows was also used. Each house contained eight pigs divided into two lots of four pigs each. M2. The temperature. relative humidity, ventilation. and solar radiation data for the winter study are shown in Appendix B. The relative humidity data was plotted for only eight weeks because there was not enough varia- tion to warrant plotting the data for the entire sixteen week period. The missing data was caused by failures of the potentiometer and the wet- bulb apparatus. The daily maximum. minimum.and mean temperatures are shown in Figures 2h, 25, and 26, respectively. The maximum daily varia- tion in the temperatures inside Houses B. C. and D are shown in Figure 27. The daily total amount of solar radiation and the normal‘amount of solar radiation is shown in figure 28. The missing temperature and relative humidity data was due to instrument failure. Temperaturg. The inside temperatures of Houses B. C. and D followed certain definite patterns during the winter study. In House 0 the maximum difference in daily temperatures was usually greater than in either House B or House D on the days when there was a large amount of solar radiation as shown in Figure 27. On these same days the maximum.temperature in House c was essentially equal to or slightly higher than the maximum temperature in House B. lhen there was a large temperature rise inside House 0 due to the reception of large quan- tities of radiation from the sun the rate of increase in temperature was usually greater than the rate of increase in temperature for either House B or House D. However. the temperature usually decreased faster in House C than in either Houses B or D. The minimum temperature at night and on cloudy days in House 0 was usually lower than the temperature in either House B or House D except when it was relatively warm outside. This was especially true when the ventilating fans were not running. 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Jill} - 1.1: i fi,1,3117-11%.! .om _ H new” vll’- - IvITlutl'L‘lutt I? .1! .., -3. Li: L I. I If! T -lth-‘ i ..n..u.a(..uvoovuc n a i H .2 s, n @330: .om .1 5 < $30: .00. w. v. N. mxmw? z. O. m .emm. .m E3 2 mom. .9 .3588 Set 8.20.3.5. 36c E:E.EE 96 £35.35 5253 855:6 on... SN 050E mg... w v _ Till. . lll‘livlill . . O '--- -——4 .h—h _.....____~ A . fill .oifitll'l.1. l 000 m n - .i! :T..-il u no: -IJIIII u no: --- u so: o0. o0 oON oOm 90¢ oOm do " HONBBBASIO BHOlVUBdWBJ. 1+7. 65:38.56. mo EcEtonoo 335 note: 9: mo octoofiocw "ecnzaotod. use 628 .3335 621 no 335 9.: .53 323308 E .8205 EoEtoaxm _E=::o_._o< 5922.2 625$ 563$. 93.831 59:22 or; ._ cocoa oEom 2: mo zoo zoom .8 20:22: 53 mo anEo BEE: on. .25 mam. 6 End. 2 mom. .9 conEoooo :5: >8 coco .8 5:22: 5.8 do EsoEe .22 och .8 23¢ mxmm? 2. m2: o. 3 N_ o. m o o n E n o v _ L _ c .y W . n __. 3.33 .w . 3_ . 3 oo_ 3 m \ ‘ V 1 _ 9 _ O a . \ m _ m _ fl ... 3 :- .\.\\ . . S ,_ e. a -. 3 3333 3 on d _._ A w \ \ m , 8 xx. _ k m m I \v “33 3 3 3 3 3 e, 3/ 333333 2.3. 3 3 a : 3 3 33333333303 V .\3 , A _ m w ammm Sm. :8» 3 2m: .haxm co< :22 .595? E «8:04.535 m 3 33 3 3 3 33 33 3 BEEP. 6.833.220 «393 wo<~+m><+m _ #655 >9 ,zofisoé mfiom mice 33 H . _ . _ _ , _ . oom 148. range in maximum and minimum temperature in House 0 was caused by the ability of the single-pane windows to transmit greater quantities of both short wave-length radiation and heat energy through the glass. There was more heat trapped in House C even though there was greater heat losses through the single-pane windows as compared to Houses B and D. However. when the source of incoming radiation was eliminated the heat losses through the single-pane windows caused the temperature to be lower when there was no solar radiation and when the temperature differences between outside and inside was large. When the ventilating fans were off there was no heat loss by ventilation. ‘Ihe conditions inside the houses were such that heat was lost only through the walls. roof. floor. and the glass windows. The heat losses were about the same except for the losses through the windows. Since the heat losses were greatest through the glass in House 0 the temperature was usually several degrees below the temperature of the other two houses when the ventilating fans were off. In House B the maximum difference in daily temperatures was less than in House C and greater than in House D. me daily fluctuation in temperature in House B was very similiar to that in House 0. The max- immn daily temperatures were usually higher than in either House 0 and D except on the days when large quantities of solar radiation were re- ceived and then the temperatures in House 0 were higher. The mean daily temperatures were also slightly higher in House B as shown in Figure 26. 'hen there was a large temperature rise inside the house due to the re- ception of large quantities of radiation from the sun the rate of increase was greater than the rate of increase in temperature for House D. the rate of decrease in temperature was also greater than that of House D. M9. These trends were caused mainly by the greater insulating value of the double-pane windows. The heat trapped inside House B was not lost as readily as in House 0. As a result the temperatures remained higher at night time causing less temperature fluctuation throughout the dw. In House D the maximum difference in daily temperatures was usually less than in either House B or House C. lhen ever there was an appreci- able increase or decrease in the temperature in either of the other two houses the temperature in this house lagged behind. 0n the days when large quantities of radiation were received from the sun the maxim daily temperature was always lower than the maximum daily temperature in either House B or House C. The minimum daily temperature was usually slightly below that of House B and slightly above that of House 0. These condi- tions can be attributed mainly to the fact that there was a smaller aroa of glass in House D. Consequently. less solar radiation was allowed to enter the house and be utilized as heat ensry. This kept the tempera- tures lower than those in Houses B and D. On the other hand. the smaller glass area maintained more uniform temperatures than in the other houses. Also. the total insulating value of the glass and the wall section that took the place of the larger windows was higher. thus causing smaller overall heat losses in the house. However. House D was at a disadvantage because the heat losses were not small enough to offset the decrease in glass area. As a consequence. when Houses B and D were at higher tem- peratures and the temperatures began to drop. the temperature in House D also dropped considerably and of ten remained below the temperature in Houses B and C. Eventually the temperature in House 0 would go lower than the temperature in House B. 50. A positive correlation was found between the inside temperature in Houses B. C. and D and the temperature in House A or the outside temperature. An analysis of the regression lines showed no marked diff- erence in slope. however. 3 Relative humidity. The relative humidity inside Houses B. C. and D did not vary according to any specific pattern as shown in Appendix B. There was. howéver. a tendency during the nhght time for the relative humidity in Houses 0 and D to be higher than the relative humidity in House B. During the day time the relative humidity in Houses B. C, and D was not appreciably different. The higher relative humidity in Houses 0 and D as compared with the relative humidity in House B was caused mainly by differences in the tem- perature in the houses. Dower daytime temperatures in House D did not permit as much evaporation of the moisture fromitho floor and litter as in Houses B and O. This caused the relative humidity to be higher in House D during the night because of the greater quantities of moisture being evaporated than in Houses B and C. Lower night time temperatures in House 0 caused the relative humidity to be higher than in House B. Vgntilation. At the start of the winter study the thermostat which controlled the operation of the ventilating fans was set at 50° 1. At this setting the fans were shut off for as long as 16 hours or more on a few occasions. During these long periods there was a large moisture build- up in the houses. In some instances the walls were completely covered with moisture. The ventilation was therefore. inadequate and the setting was gradually lowered to “0° 1. Ventilation was still inadequate. but 51. “0° F. was considered to be a practical minimum; so. a time clock system of control was preposed. On February 3. 195M. a time clock was installed to control the opera- tion of the ventilating fans when the thermostat did not call for ventila- tion. The time clock turned on the fans for a desired period of time from 0 to 30 minutes once every half hour. It was first set so the fans oper- ated for seven and one‘half minutes once every half hour. This did not provide enough ventilation so the setting was changed after two weeks to operate for ten minutes once every half hour. This period of operation provided a sufficient change of air when the thermostat did not call for ventilation so this setting was maintained throughout the remainder of the study. During the winter study there were a number of days when the tem- peratures in Houses B and 0 reached 700 to 80° I. even though the out-- side temperatures usually remained below 50° 1. These high temperatures were undesirable because a maximum temperature of 60° - 650 F. is do- sirod for hugs. The hogs would lay in the shade at these temperatures while at lower temperatures they would lay in the sun light. It was ap- parent that the capacity of the ventilating fans was inadquate even under winter conditions. A very important part of ventilation is proper circulation. A van- tilating system with inadequate circulation does not take full advantage of the ventilation. In order to determine whether or not there was good circulation in the experimental houses a smoke bomb test was made. The results of this test are shown in Figures 29 and 30. ‘mese pictures show that there was fairly good circulation in the houses. However. 52. I 3 3 ~ , .3 3 ' . . ,, - r 3 . .,:.:’- »‘ ~ 3. . ..- _ p a ‘ -, ,3 l 3 ”I" '3 . Li ' > JR}: Figure 29. no distribution of the air as it enters the house through one of the air intakes in the rear wall. .,: a ‘ - I. “ JMWL figure 30. The distribution of the air as it moves across the front of the house towards the air intake of the fan. 53. there is clearly room for improvement so that the air will circulate more uniformly through the houses. Heat 122 . The heat laxnps placed above each waterer were not turned on by the thermostat during the whole winter study. The heat produced by the hogs and the heat stored from solar radiation was sufficient to main- tain the temperature in House 0. the house where the thermostat was lo- cated. so that heat from the infrared heat lamps was not required to keep the water in the drinking fountains from freezing. frost and moisture accumlation, frost and condensation on windows is very comon in farm structures. This is particularly true of single- pane windows. However. moisture does not condense on double-pane windows nearly as soon as it does on single-pane windows. This was particularly noticeable in the winter study. There was frost formation on the single- pane windows whenever the outside temperature went below about 25° 1'. The frost usually was melted by noon of the following day. . However. there was never any frost formation on the double-pane windows. A typical in- stance of when this happened is shown in figures 31. 32 and 33. There was moisture on the double-pane windows but the inside surface temperature was not low enough to cause frost to form. loisture condensation and frost formation are very objectionable. The moisture will cause wood window frames to rot. It will also elimi- nate sale of the radiation which would otherwise be transmitted through the glass. The condensed moisture on the windows cannot be eliminated by ventilation. The moisture within the houses cannot be entirely elimi- nated. These factors make it almost impossible to completely eliminate condensation on the windows. The moisture content of the air can be 51$. figure 31. A typical view on cold mornings showing how the single-pane windows frosted over while the double-pane windows did not. reduced only by replacing the moisture laden air in the houses with re- latively dry air from outdoors. Double-pane windows have definite advantages with high moisture conditions such as prevail in hog houses. They are the most effective means of increasing the inside surface temperatures by increasing the resistance to heat flow through the glass itself. Leonhard and Grant (H2) State that the prevention of frost and condensation by constructional Means is more applicable where high relative humidities prevail. The benefit derived from even a few degrees increase of the inside surface 1iunperature of the glass is very great considering the fact that con- densation and frost appear on the coldest days of winter. Ventilation and circulation are also a partial answer to this prob- l’nl. When condensation and frost formation are the greatest the outside 55- E Figure 32. he single-pane windows were covered a with frost up to one-sight inch thick on ni ts when the temperature outdoors went below 25 I. Figure 33. The double-pane windows never had any frost on then but Ieisture did condense en the in- side surface. 56. temperature is low. thereftre the moisture content of the outside air is also low. Drawing this air into the house will lower the inside relative humidity and help prevent condensation on the windows. However. if the incoming air is very cold and the inside relative humidity is high. the incoming air will immediately condense and there will be rain in the house. This condition will have a detrimental effect on the environment in the house by making the litter and floor very wet, causing the rela- tive humidity to eventually increase. On several mornings during the winter study this happened but it only lasted for a short period of time as it was cold and clear outside. The morning sun sooniheated the houses and corrected the situation. Air circulation over the inside surface of the glass reduces the inside surface resistance and-the inside surface tem- perature is increased thus permitting a higher relative humidity without condensation on the windows. however. there is also an increase in the heat loss through the windows resulting from the increase in air'motion. The chief factors influencing the deposition of moisture and.the formation of frost are the dew-point temperature of the inside air and the temperature of the inside surface of the glass.(h2). The dew-point tanperature is determined solely by the moisture content of the air. It varies directly with the change in moisture content. If it were possi- ble to keep the dew-point temperature of the inside surface of the glass above the dew-point temperatures of the inside air. frost or condensation would never form on the glass. Qgglitz of the air. Observations made during the winter study indi- cate that the quality of the air in House 0 was usually better than the quality of the air in either House B or House 0. Ammonia fumes were not 57. as strong in House 0 as they were in the others. In some instances no difference could be detected between House B and House C. However, the quality of the air in House D was usually inferior to thequality of the air in both House B and House 6. The fact that the quality of the air in House D was inferior to the others may be due to the decreased amount of radiation available to heat up the house and help vaporise the moisture in the litter so that it could be removed by ventilation. This would allow greater quantities of male fumes to be formed. The differences in the quality of the air of the houses was also due in part to the different amounts of water consumed. and excreted by the 11038. The hogs in both House B and House D consumed more water and therefore excreted more water which increased the forma- tion of amonia fumes. Also, differences in the amounts of straw in each house would have an effect on the moisture in the litter and may have caused some differences in the quality of the air in the houses. Sun patternl. During the winter study a series of three sets of pictures were taken at intervals of four weeks to show how the sun pattern changed in the houses. All the pictures were taken at noon. One series was taken in House 0 and the other series in House D. These pictures are shown in Figure 31$ through 39. lbs sun patterns in House 0 are on the left and the patterns in House D are on the right. It is evident that there was a much greater area exposed in Houses 13 and 0 than in House D for reradiating long wave infrared radiation to heat the houses. Feeding trig . The results for the feeding trial for the winter study are compared in Table 11. These are average values for the entire 16 week period. The data for each weigh period is shown in Figures ‘40 through m4. 58. Figures 3’4 and 35. January 21. 195 . figures 36 and 37. De sun patterns in Houses 0 and D. respectively. on )‘sbruary 17. 195%. Figures 38 and 39 “rah 17a 195k. 59. TABLE II SUMMARY or THE RESULTS FOR THE HOG moms TRIAL or THE Hum STUDY or 1953-5h Treatment House A House B House 6— House D number of pigs 8 8 8 8 Awerage initial 3u.2 3h.6 3u.6 3N.6 weight in pounds Average final 175.5 202.h 17h.7 199.6 weight in pounds Average daily 1.26 1.50 1.25 . 1.1t8 gain in pounds Average daily food 5.33 6.00 5.11 5.81; consumption per pig in pounds Pounds of feed 11.23 11.01 n.09 3.97 consumed per pound of gain Arerage daily - 1.68 1.36 1.5% water consumption in gallons Gallons of water - 1.13 1.08 1.0% consumed per pound of gain Gallons of water - 0.28 0.26 0.27 consumed per pound of feed 462m .253 of do noted see; 02:. zoom .8 mo... Lea Sow 26v 3055 en... do 959... mxmm; 2. 92:. w. v. N. o. m w v N O a a a m _ O _ d O n 0.. N O S .d 3 no a. d 9. {I}- 3 on a mono: Illllll 0 owner m manor 4 8:0: 61. do notea x83 02: zoom c8 mo: Lea cozaeamcoo coma mxme 2. msE. m. e_ N. o. m m .32»... LEE; 9.: .366 3226 of. z. 8:9... Old 83:! SONnOd ((000 meOI mmDOI O. 62. 462w 82:; of .6 voted x83. 9.: zoom no“. Eco do ucaoa .3 35:28 38 .6 2525 on» No 8:9... mxmm; 2. mi:- N d O m .. m 0 VVI... S \\ d . \ 3 H. .d v 0 .n N O m o wmnox lllll Ill 0 Manor -;..--..1...- m umaor < meOI. 63. .255 .253 a... do cocoa x09... 95 zoom .0. mo; .3 cozaEamcoo .20; 2.8 omega och .me 839.... mxme 2. mi... w. v. N. o. m m e N o 0 m6 ... . \\. W - .\.\\ .l - \\\\ o. .I \\\ m \ S tw\ \\\ 3 L... \ kl ?. no .....\\ U H \\lfi\\ [\ \\\ \ 0 Manor Illl.|..- \ o wmzox m. mwaoz 0N 6h. .32.... SEE of mo uotma .33 03. none. .8 Eco no 958 .8 3532.8 .203 cc .5660 00990 on... we 8:9... mxmm? 2. m2...- m. e. N. O. m w v N O 5 . Omd 55555555- 5-5555551 NJ-- ..5 5 mad . \w I I I I I I L K. \ n I- - - -55----5- 5 5 555,..- 2m II‘ III In... lllll I I .7.“\\ 4% O .525 l/ \ - ..- . u- . ..J’Jfi _ d x . . 3 \ . 5 U \ \r 55.5. 5 -. ..5\ \ - 5 -455 5.5.4-.. . .fi 5 -55- , .-5I5.-5 555 I5 wN. % ..\ ,6. .H ..\ 1. N x . 0 5.5555... 5.555 -5.5-+-55,55555 .. 1. 55,5 I5-5515 5-- -5 , 5.7! 5. 55155 5.5 5 .. I 5- 5.5.55. I 5.5 00.— D mmDOI 555.555 0 mmDOI .1: m uwDOI 65. The hogs in Houses 13 and D made faster gains than those in either of the other two types of housing for the entire study period except during the eleventh and the twelfth weeks when the hogs in House A made about the same gains as those in Houses 13 and D, as shown in Figure ho. Table 11 shows that the hogs in House B made the highest daily gain of 1.50 pounds while the hogs in House 0 had the lowest average daily gain of 1.25 pounds. The final average weight figures in Table 11 show that for the entire period the hogs in House 0 gained no more than those in House A. The increase in the average daily gain per pig as the study progressed was due to the increase in the size of the animals and the higher temperatures which prevailed in all the houses. No direct rela- tionship was found betwoen the variations in gains and the temperatures in the houses. The difference between the hogs housed in the houses with double-pane windows and the others amounted to about 25 pounds or about two weeks growth. In other words. the hogs in Houses 3 and D reached market weight two weeks earlier than the hogs in Houses A and G. 5 The final weights were analyted statistically by an analysis of covariance. There was a significant difference between the means of the weights of the hogs in House B and House D and the hogs in House A and House 0. The difference was significant at the five percent level. the least comon difference found to be significant was 21.03 pounds. There was no significant difference between the hogs in House B and those in House D. Likewise. there was no significant difference betwoen the hogs in House A and those in House 0. Ho definite pattern was found for the efficiency of gain. The hogs in Houses B and D consumed more feed per pig than did the hogs in both of the other two types of housing except during the thirteenth and fourteenth weeks when the average daily feed consumption per pig for the hogs in House A was higher. Figure 541. The feed consumption per pound of gain as shown in Figure 1&2 did not follow any certain trend. The differences during the first two weeks of the study were due primarily to excessive wastage of the feed. After this was corrected there was little variation between the hogs with different types of housing except during the last four weeks of the study when the hogs in House A showed a large increase in the mount of feed consumed per pound of gain. This was also due to excessive feed wastage. hence this part of the feed data is not reliable. The high amount of feed consulted per pound of gain by the hogs in House A was also due to the increase in the amount of feed necessary to maintain body temperature under the cold- or conditions that existed in this house. The hogs that made the greatest gains consumed the greatest quanti- ties of water per day as shown in Figure 553 and Thble II. This was also partly true for the average amount of water consumed per pound of gain especially for the hogs in House B as shown in Figure 11-h. The average amount of water consumed per pound of gain by the hogs in House D was less than that consumed by the hogs in House 0. Table 11. the average amount of water consumed per pound of feed was practically the same for the hogs in Houses B. C. and D. This indicates a direct relationship be- tween the amount of feed consumed and the amount of water consumed. Ho water consumption records could be made for the hogs in House A. 6?. The conventional house. The hogs in House A were hardly ever as active as the hogs housed in the experimental houses. Many times they were observed all huddled together. as in Figure N5. in order to keep warm. In contrast. the hogs in the other houses were very active and were obviously much more comfortable. Chewipg the at”. hiring the winter study a very marked difference was noticed in the tendency of the hogs in Houses H. C. and D to chew at the gates which divided the houses into two pens. his hogs in House 0 showed a such greater tendency to chew the gates than did the hogs in either of the other two houses. This is clearly shown in Figures 116 and 5+7. The hogs in House 0 nearly chewed through parts of the gates whereas the gates in the other two houses were virtually untouched. .A' - . , . _.. '. . Figure 1&5. A typical sight in House A during the win— ter study showing how the hogs all hudrned together to keep warm. 68. figure ’46. 'lhs gate in House c was all chewed up. Figure ‘47. its gates in both Houses 3 and D were only chewed a small amount. 69. Conclusigng. The results from the winter study indicate a defi- nite advantage in housing swine in solar orientated houses with large areas of double-pane windows. It was clearly evident that the hogs in both houses with double-pane windows made better gains than those in either of the other two types of housing. The hogs in House 0 did not gain any more than those in House A. we environmental temperatures in House B and D were less vari- able than those in House 0. This was especially true of House D. Further more. the minimum temperatures in House 0 were usually lower than mini- Imas temperatures in either House B or House D. The differences in the gdns of the hogs in the experimental houses can be attributed to these facts. The hogs in House A were definitely at a disadvantage. The tempera- tures outdoors and in this house were considerably lower than those in the experimental houses. Therefore. it was necessary for the hogs to utilise more feed to maintain body temperature and consequently they were unable to make gains in weight as fast as those in the other houses. As the outside temperatures became wamer the hogs made better gains but the gains were still less than the gains of the hogs in Houses 3 and D. Part III - Analysis of the periods without any animals in the houses. _l_1_._n_t_e£. Prior to the start of the winter study a two week study was made using the three experimental hog houses without any animals. During this period the houses were tightly closed and neither mechanical ven- tilation nor sun shades were used. let-bulb temperatures were not taken due to the possibility 6f freezing-and because the relative humidity was not considered to be important in such a study. 70. Several very noticeable trends were observed during the two week period. On the days when there was an appreciable amount of solar radi- ation the temperature in House 0 was four to seven degrees above the tem- perature in House B. On these same days the temperature in House D lagged behind the temperature in House B by as much as 12 degrees. The tempera- tures in Houses 3 and C rose as much as 30 to 35 degrees above the temp peratures outdoors. These trends were somewhat reversed when the tem- peratures began to fall in the afternoon. The temperature in House 0 was as much as five degrees below the temperature in House B. The tempera- tures in all the houses gradually dropped until they were the same as the outside temperature. It took from six to ten hours for the temperatures in.the houses to return to the outside temperature. The differences in the temperature inside the houses depends mainly upon the outside temperature and the quantity of solar radiation. The smaller the difference between inside and outside temperatures the greater the difference in the rate of heating and the smaller the difference in the rate of cooling and vice versa. The effect of nocturnal radiation was noticeable on clear nights. On these nights the radiation exchange with.the atmosphere made the inv side temperature of both.Hbuse B and House 0 drop below the outside tam- perature as much as three degrees. No detectable effect was noticed in House D. During four days of the study without animals in the houses. a trial run was made in House D with the heat lamps that were placed above each waterer. The inside temperature remained from ten to fifteen degrees above the outside temperature during the daytime as well as at night. 71. m. A second study without any animals in the houses was also made prior to the summer study of 1951i. During this three week period the houses were completely closed. no mechanical ventilation was used and the windows were shaded. Wet-bulb temperatures were not recorded during this period. A few noticeable trends were also observed during this period. The temperature fluctuation which occured in the winter when no animals were in the houses and the windows were not shaded was eliminated. When the outside temperature dropped the temperature lagged behind about the same in all three houses. The temperature difference was about eight degrees. lhen the outside temperature increased it was as much as eight degrees above the inside temperature of House 0. the temperature in House B was usually one to two degrees lower than the temperatures in House 0 and the temperature in House D was usually one to two degrees lower than the temperature in House B. A thermocouple was placed about an inch above the floor in House B to determine the difference. if any. in the temperatures at different heights above the floor. It was found that the temperature next to the floor was as much as five degrees below the temperature at a height of five feet above the floor. W. The differences between the amount and type of glass used in the houses as it affected the temperature in the houses was very noticeable. Both the differences in the insulating values and the dif- ferences in the transmission of radiant energy were also very noticeable. The single-pane windows transmitted more radiant energy than did the double-pane windows and they also caused greater heat losses. The mailer 72. area of double-pane windows excluded a large amount of solar radia- tion which occured in the other houses. 73- CONCLUSIONS Since the data reported in this thesis is based on only one years results, the following conclusions must be considered tentative and sub- Ject to revision when additional data has been collected. 1. Double-pane windows used in solar orientated houses for winter housing of hogs. provided a more favorable temperature environment which was more conducive to higher rates of gain in weight. 2. Double-pane windows utilise solar radiation more efficiently than do single-pane windows for use in heating hogs houses by conserving more of the long wave radiation that is trapped in the houses and con- verted to heat energy. 3. Single-pane windows cause wider fluctuations in temperature in the hog house than do double-pane windowsbecause they transmit more solar radiation during the day and cause greater heat losses at night. M. Ventilating fans in solar hog houses should have enough capac- ity to keep the temperature below the maximum desirable.. This will permit the use of a maximum amount of solar energy. 5. ‘Jhe area of double-pane windows on the south wall of a solar hogs house should be a maximum for any particular design in order to take advantage of. as much solar radiation as possible. 7h. SUGGESTIONS FOR FUTURE STUDY 1. The recording of temperature and relative humidity data in the three experimental hog houses should be continued for at least three years since one year's data does not represent a sufficient sample of climatic variability. A longer period of record is needed before recomnendations for the use of double-pane windows in a solar hog house can be developed. 2. A study should be made using large areas of tripledpane win- dows in hog houses. Miller and Black (M) state that a triple-pane win- dow with the glass spaced one-half inch apart is equivalent to a 12 inch brick wall in insulating value. A window such as this would conserve a greater percentage of the heat trapped in a hog house from solar radia- tion than conventional windows. 3. Heat-absorbing glass used as the outside pane of a double-pane window with ordinary window glass for the inside pane reduces the summer cooling load considerably. Shaver (52) states that a heat-absorbing glass will transmit only 1&2 percent of the incident solar radiation as compared with 88 percent for ordinary window glass. The amount of visible light transmitted and the amount of solar radiation reflected is approximately the same for both types of glass. Heat-absorbing double-pane windows of this type would reduce the summer cooling load in a hog house consider- ably, especially if some type of mechanical cooling is used, while the mount of visible light would be the same. An investigation should be made using this type of window in the experimental houses during the Elm-nor. 1+. Ultraviolet rays are not transmitted through glass. However, beneficial effects have been observed on some animals from ultraviolet rays. The use of ultraviolet light from a low pressure mercury vapor lamp should be investigated to see if there are beneficial effects on hogs. 5. The orientation of solar houses has been in every case. south- facing. A study of heat gains through walls and roofs as affected by solar radiation (26) has shown that the heat inflow through the east. south. and north walls was 83. 75. and 186 percent. respectively. of that for the west well. That is, the heat gain due to absorption of solar radiation by the outside surface of the structure was greatest in the west orientation. This should also be true of the transmission of solar radiation through glass. merefore. a west or southwest orientation for solar hog houses should utilise more solar radiation for heating the houses. A study should be made to see if this is true. 6. The windows of the experimental hog houses were all set in a vertical position. This made it impossible for the sun's rays to be nor- mal to the glass surface. The greater the angle of incidence the smaller the amount of solar radiation transmitted through the glass. A study should be made with the windows at an angle which will decrease the angle of incidence of sun's rays. The windows could either be adjust- able or set at an angle which would allow the maximum tranenission of solar radiation for the period under study. 76. amass um 132mm: THE svmn STUDY or 1951: At the end of the winter study it was found necessary to make sev- eral changes in the houses. A new floor was required because the three- eighths inch plywood would not last for another study. Vertical grain tongue and.groove fir flooring was laid in all three experimental houses. A tar paper vapor barrier was placed underneath.the flooring. The floor was covered with a non-skid floor mastic which was put on with a trowel. A ten inch propeller fan with an air flow rate of about 300 cubic feet per minute was also installed in each house. The air intakes in the rear wall of the houses were enlanged and two more were added. The air in! takes above the doors were reopened. This gave a total area of 100 square inches for the air intakes in each house. The section of the-feeder that was inside of the houses was made one and one-half inches deeper in order to help eliminate some of the feed wastage. House D, the house with half-sise double-pane windows. was changed so that there was no light coming into the house except through the air intakes and exhaust. This Ia! done by placing a panel of insulating sheathing next to the inside surface of each window. A sheet of aluminum covered roofing was placed between the glass and the sheathing with the aluminum.next to the glass to reflect the radiation incident upon it. 77. APPENDIX.£ The Temperature. Relative Humidity. and Solar Radiation Data for the Summer Study é tsosg. 'Nmruowfiv :0 swam-radon “was warm on: so Burnout?“ Ivmztmwfiv pus 'suo‘ flhssnpsr tufltd JO neean sq: Qttl sorgszsdooo at UOIQRQS guemraedxm {sinstuorafiv nsfirqorn ‘aorsseg qnxseseg stBOIOJpAH uefirqorw qu mom; psi Temperature in Hones C, the house with single- pane windows. Temperature in House B. the house with full size double-pane windows. Temperature outdoors or 7ko the temperature in House» A on the concrete slab. ..... 100 80 a - m Ogle/[comb 0 Daily total of direct and and sky radiation received sky radiation received on on a horisontal surface A, ~ .. a horizontal surface at at East Lansing. Michigan! ‘ i~ :1 : East Lansing, Michigan! —IO°' 1; f7 20 Hourly totals of direct 4 8 SC 4 8 AM PM AN RM MON: .‘1' TUESDAY TEMPERATURES AND SOLAR RADIATION °Kpngs zemmns aqq so; asap uoxssrpns autos pus exnssxedmeq sq: go norqeustdxa '61 o/‘loo‘wb 8 A 02‘“ AM I0 AM " AM PM AM PM AM ‘ AM PM M 0NDAY T UESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY SUNDAY WEEK OF AUG' (3‘9) TEMPERATURES AND SOLAR RADIATION p I. I T Iqr . .OO_ _ MEVH—H.u.~w-~de_sflru L.A.r.,w. ..s H ._.-F.u .._ . .2. .u... I z. « °\08‘ AM PM MONDAY TUESDAY WEDNESDAY WEEK OF AUG. (IO-I6) AM AM THURSDAY FRIDAY SATURDAY TEMPERATURES AND SOLAR RADIATION I A SUNDAY 80 A - - m I Ozwo/loewoo ) ( 20 PM h >._._D_23I u>_k> >135: 11 :4 !< In 24 In 14 11 —m.HI~__I—_H_H~—P~__~*Ha4_fiH—I_WW~4—H~_A4—~H_HAAHH14HHHHHHJHHH_HHFH~_~_fiHH~Hp~—_fi~_I_I-_H__Fhfloo_ >._._O_ZDI Mahdi—mm >._._Q_ZDI u>E.<-.mm guns: .2; to 3mm: >495: .3 In. !< 24 0/103 396 8 .b 03‘” AM MONDAY TUESDAY WEEK OF AUG. (I7- 23) AM- AM PM AM WEDNESDAY AM THURSDAY FRIDAY SATURDAY PM SUNDAY TEMPERATURES AND SOLAR RADIATION '92 >4023m 3m 34 >295me u>_h<4wm >> It 893.3 .22 do gum; 20mm? 3202 24 (O . ls. . s‘. Rs. AM AM MONDAY TUESDAY WEDNESDAY WEEK OF AUG. (24-30) PM AM THURSDAY FRIDAY TEMPERATURES AND SOLAR RADIATION H SATURDAY SUNDAY 80 . . m o/loewb O .h 02‘” 20 PM MONDAY TUESDAY WEEK OF AUG. 3I- SEPT. 6 AM AM PM AM WEDNESDAY THURSDAY FRIDAY TEMPERATURES AND SOLAR RADIATION PM AM ~ SATURDAY H AM SUNDAY PM 0/103 3116 8 4;. 02‘" '63 Id ma .2335 5:3 . er .. .'-|".lx_.sn... . st....u....r§IIIll—.?u8 ..oo. hamstealllllleEI 'Illw'l' 1. ll.“ 3.6.... ..ll 52.... 2...... .2... . .v ‘ ... ... .o . . gigafiasls..- dune... . - =7. :5 5.. as . . ..nnnnnfimru. ..5; . "..i:§ #196...» i ..I... .\°....4 90. APPENDIXIB The Temperature. Relative Humidity. Solar Radiation. and ventilation Data for the linter Study 91. Explanation of the relative humidity data for the winter study. >P_Q_ZDI m>_h<.._wm Squaw“: .1355 .21. In 7d . 34 .333 a: nuisances page on» 3 Eocene on» as AME as :3 .33... 3.9.3.6. 5.3 semen e5 .o easem S 5.3.5.. .523. Seconds seen negooe e:- Hdc our. 3qu 2.3 .n eecem 3 3.3.55 eeaasaem Jeep-«e sedated»:- A»: e26: e5 .0 sad—om a. 5.83.5 .5238 .3333 3333 33:5 ’leceised from the Michigan Hydrologic Research Station, Michigan Agricul- tural Experiment Statics in cooperation with the Bureau of Plant Industry. Soils. and Agricultural Engineering of the United States Department of Agriculture . \svfI‘...L..III rLI.Ih . rILII TIF- _ . p I n r b .. g a. L w. h . h . h fl “.1.th “I; H . . . ~.£.1l - r III‘II Ir 'axngtnoxxfiv JO quequedoq seqeag pezrun sq: 50 Surxeeurfiug {sznqtnorzsv pus '91102 migsnpux sustg go naaxng sq; qgra uorgsxedooo n1 uorgegs quemrxedxg {exnatnorxfiv uafirqorw ‘sorsasg qsxaeeeg ogfiotoxpxn uefiruorw sun mos; DGAIBQGE. Ventilating fans on for 7% minutes once every Ventilating fans "off“:/// 7 I half hour. Ventilating fans “on”f/ Ventilating fans on for minutes once every half hour. Temperature in House 0, the house with single- pane windows. Temperature in House B./ the house with full size double-pane windows. Temperature outdoors or the temperature in House L. A and on the concrete H slab. Temperature in House D, the house with double- windoWs half as high as the windows in the other experimental houses. 4> on C)éu3/1001u6 (3 Daily total of direct and sky radiation received on a horizontal surface at East Lansing, Michigan? Hourly totals of direct and sky radiation received on a horizontal surface at East Lansing. Michigan? 10 ' TEMPERATURES AND SOLAR RADIATION °£pnqs saints sq: so; snap uorietziuei pus uorqerpea IBIOS ‘exnisxedmeg sq; ;o uorgeuetdxa >._._D_ZDI u>:to=231 nah/Bum ENLN. duo no xuma >> >403: >> >._._O_S.DI m>_._.<0Eu >._._Q_S_DI u>:.<:_mm :75 .25. no xmwi ><9mu >> >é“ MONDAY ' TUESDAY WEEK OF MAR. (I5-2l) AM AM PM WEDNESDAY THURSDAY FRIDAY TEMPERATURES AND SOLAR RADIATION PM , AM SATURDAY .' ‘ AM SUNDAY PM o/‘Ioo two 8 A 02w o/103'wb 8 A 02‘” AM AM PM AM PM AM M p“ MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY SUNDAY K OF M . 22-23 ' WEE “R I ) TEMPERATURES AND SOLAR RADIATION 60 9/103'wb A 02‘“ IO AM AM PM AM PM AM , ~AM ., p” MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY SUNDAY WEEK OF MAR' 29'APR'L 4 TEMPERATURES AND SOLAR RADIATION a ‘dwal .30 80 00 (D O 0 so ‘dwu 0/1033115 A 02‘“ 20. AM AM PM AM PM AM AM MONDAY TUESDAY WEDNESDAY THURSDAY PM FRIDAY SATURDAY WEEK OF APRIL (5-II) .’ ‘ SUNDAY TEMPERATURES AND SOLAR RADIATION ' 91'! 117. GLOSSARY Angle of Incidenc - The angle between the direction of the rays of the sun and a perpendicular to the surface under consideration. Atmospheric Eggsorptigg - The absorption of solar radiation by the components of the atmosphere such as oxygen, ozone. carbon dioxide and water vapor. Direct Solar Radiation - The radiant energy received directly from the sun. . Doublgggane Windows - Two panes of glass separated by an air space and fastened together around the outer edges with a strip of lead which forms an air tight metal to glass bond. Grg-calorig - The amount of heat energy required to raise the tem- perature Of one gram of water at 15° 0. one degree centigrade. In rect Difms or atio - The scattered solar radiation received by the earth from the atmosphere. leg; Sglgr Distggcg - The mean distance of the earth from the sun. It is an arithmetical mean distance between the greatest and least dis- tances between the earth and the sun. Nocturnal figdiation - Radiation exchange between the earth and the atmosphere at night. Normal Incident agatiga - The impisganent of solar radiation on a flat surface at 1‘1ng angles to the sun's rays. ghetonhere of the Sun - me layer from which most of the sun's light is emitted which reaches us directly without absorption and re- enissioa before leaving the sun. The photosphere may be regarded as the layer which is the limit to which we can see into the interior of the sun. filar Altitude - The angular elevation of the sun above the true horizon. §glgr Congtan - The rate at which solar radiation is received out- side the atmosphere on a surface that is normal to the incident radia- tion. at the earth's mean solar distance from the sun. The value of 1.9” gram-calories per square centimeter per minute is the common one used. Etal Incident Solar Radiation - The total direct plus diffuse solar radiation measured perpendicular to the surface under consideration. Transmitted Solar Radiation - The portion of the total incident rad- iatioa which passes directly through the glass. 117. GLOSSARY Angle of Incidence - The angle between the direction of the rays Of the sun and a perpendicular to the surface under consideration. Atmospheric Absorption - The absorption of solar radiation by the components of the atmosphere such as oxygen. ozone. carbon dioxide and water vapor. Direct Solar adiation - The radiant energy received directly from the sun. Dggblggane Windows - Tho panes Of glass separated by an air space and fastened together around the outer edges with a strip of lead which foms an air tight metal to glass bond. W - The amount of heat energy required to raise the tem- perature of one gram of water at 15° 0. one degree centigrade. In rect Diffus r ati - 'lhe scattered solar radiation received by the earth from the atmosphere. 8 r t - The mean distance of the earth from the sun. It is an arithmetical mean distance between the greatest and least dis- tances between the earth and the sun. Nocturnal gdiatign - Radiation exchange between the earth and the atmosphere at night. [gm Inciggnt gflgtign - The impinganent of solar radiation on a flat surface at rigit angles to the sun's rays. ghgtolphere of the E2 - me layer from which most of the sun's light is emitted which reaches us directly without absorption and re- usission before leaving the sun. The photosphere may be regarded as the layer which is the limit to which we can see into the interior of the sun. glar Altitgdg - The angular elevation of the sun above the true horison. §glar Congtant - The rate at which solar radiation is received out- side the atmosphere on a surface that is normal to the incident radia- tion. at the earth's mean solar distance from the sun. The value of 1.9“ gram-calories per square centimeter per minute is the cannon one used. gotgl Incident Solar Radiation - The total direct plus diffuse solar radiation measured perpendicular to the surface under consideration. Trangittejfi 803L111: Mails; '- The portion of the total incident rad- iation which passes directly through the glass. 118. BIBLIOGRAPHY l. Abbot. C.G. (1926). Influences of sun rays on plants and animals. Annual ngort‘gg the Smithsonign Institution. pp. 161-173. U.S. Gov't. Printing 0ff.. Washington. 551 pp. 2. (1933). How the sun warms the earth. Annual Report lg§.§hg Smithsonian Institution. pp. 1h9-179. 0.8. Gov't. Printing Off.. Washington. E75 pp. 3. .Alford. J.8.. J.l. Ryan. and 1.0. urban (1939). Effect of heat storage and variation in outdoor temperature and solar intensity on heat transfer through walls. erican ciet g;_Hg§tigg‘;g§,V.gtilatigg Eggiggggg. Transactions. E523b9-39 . h. Anonymous (19N6). Hbat gain from winter sunshine. 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'~' in.“ _ --—*———~k, N21 .5 ‘54": XL “.‘ M'°I’iifi1@fuilfl@fl7uflfiflfljflfifliwflffllfiih'fl