d project of Volunteers irl Asia . 4 Design Concedzs by: The American Institute of Architects Research Corporation Published by: The United States Department of Housing and Urban Development Office of Policy Development and Research Washington, DC 20410 USA Paper copies are $ 2.30. Ask for stock number 023-000-00334-l when ordering. Available from: US Government Printing Office Washington, DC 20402 USA Reproduction of this microfiche document in any form is subject to the same restrictions as those of the original document. I U. S. Qepartment of Housing and Urban Development Office of Policy Development and Research MAY 1976 by The AIA Research Corporation Washington, DC for The US Department of Housing a.nd Urban Development Office of Policy Development and Research Contract IAA H-5574 The research and studies formlng the basis of this report were conducted by The AIA Research Corpora- tion pursuant to a contract with The Natlonal Bureau of Standards’ Center for BulldIng Technology, lnstltute fol Applied Technology. in support uf The Department ol- Hous:ng and Urban Development Office of Policy Developmellt and Research The statements and con- clus~ms contalned hereln are those of the contractor and de not necessarily reflect the views of The National Bureau of Standdrds or The Qepart,;lent of Housing and Urban Development . -- Fnr ealm hv thm C~mnrintnnrinnt nf l%w-~wnnnt~ 1 I C &wnmmnnt Printinrr nffirn -.. FOREWORD Solar energy has g-dptured the imagination of the American people. I? has done so for two good reasons. Frrst. the rising cost and uncertain avarlabrlr- tv of conventronal fuels has made the use of solar energy for space heating. cooling and domestic water heating an increasrngly attractive alternatrve. and second, the envrronm~ntal problems associated with most conventional fuels are not present with solar energy. The Department of Housing and Urban Development (HUD) In cooperation with the Energy Research and Development Administration (ERDA) and other federal agencies has undertaken an extensive program to demonstrate the economic and technical feasibility of solar heating and cooling. In response to the Solar Heating and Cooling Demonstration Act of 1974 and other federal legislation, HUD, ERDA and other designated agencies will manage a large scale research, development and demonstration ef- fort to remove the barriers. both technical and in- stitutional, to the widespread application of solar heating and cooling systems. One important component to the successful ac- complishment of these objectives is the timely dis- tribution of information. Therefore, as a first step to an increased awareness and understanding of solar heating and cooling and its application to dwelling design, HUD is making available this publication. It is a general resource document intended for use by designers, home builders, community leaders. local officials and home owners who are interested in the application of solar heating and cooling to resrdentral structures or are considering participatrng rn the federal solar energy program The publrcatron provides hrstoncal background rnfor- matron. a concrse report on existrrrg solar dwellrngs and systems, a list of design considerations and numerous dwelfrng and site design concepts It IS not the intent of this publrcatron to present housing nesrgns ready to build but to identify a basis for future solar design by professionals We encourage all interested parties to partrcrpate in the development and applrrarron of solar eneryy We hope this publicatron assists In that effort Charles J Orlebeke Assistant Secretary for Policy Development and Research Department of Housing and Urban Development PREFACE This pubiicatron IS about solar energy and how its use for heating and coolrng WIII effect dwelling design and site plannng. It has been prepared as a brief rntroductron for consumers, desrgners and builders interested In solar heating and coolrng Beginning with a bnef history of solar energy applications, a more thorough descriptron of solar energy components and how they are organized into heating, cooling and domestic ho+. water systems follows Next. factors which influence the design of solar dwellrngs and systems are drscussed. The remaining portion of the publication rllustrates dwell- rng and site design concepts responsrve to these fac- tors for varrous housing types. solar systems. and clrmates The document was prepared for The Department of Housrng and Urban Development’s Office of Policy Development and Research by The AIA Research Corporation under contract with The National Bureau of Standard’s Office of Housing and Building fechnology. Assistance was received from ten sub- contractors - eight architectural firms and two schools of architecture - who prepared the bulk of the research information and design concepts in- cluded in this publication. The architectural firms were: The Continuum Team, Bridgeport. Connec- ticut; Donald Watson, AIA, Guilford. Connecticut; Grffels Associates, Detroit, Michigan: Joint Venture, Boulder, Colorado; Massdesign. Cambridge, Massachusetts; RTL. Inc.. Paramount. Calrfornia; The Architects Taos, Taos, New Mexico; and Total En- vironmentai Action, Harrisville. New Hampshire. The two schools were The School of Architecture and AIA Research Corporatron. IS rcsponsrble for Chapter 5 Envrronmental Studies of the Unrversrty of Detroit. design concep!s. graphics and productron of thus and the College of Architecture of Arizona State publrcatron Peter Clemons. graphic designer University. Their efforts have added much to the ad- vancement of solar dwelling design John P Eberhard. President The AIA Research Corporation Charles McClenon and Gary Robrnette of the Amertcan Socrttv of Landscape Architects Foundatron with the assrstance of SIX consultants are responsrble for preparation of research rnformatron regarding site planning and solar energy utrlrzatron The consuliants were Sasakr P.ssocrates, Watertown, Massachusetts. Rahenkamp Sachs Wells and Associates. Philadelphia, Pennsylvanra. Sasakr. Walker Associates. Inc. Sausalrto, Calrfornra; Johnson, Johnson and Roy Associates. Anrr Arbor. Mrchrgan: Land/ Design Research, Columbra. Fnaryland; and Edward D Stone, Jr. Associates. Ft. Lauderdale, Florida. Numerous individuals. organizatrons. and federal agencies have contributed to the completion of this research undertaking. We would especially like to thank Charles A. Gueli. Prqect Director, and Director. Community Design Research Program, HUD; Joseph Sherman and David Moore, Division of Energy. Building Technology and Standards. HUD: and Thomas Faison and Robert Dikkers. Office of Housing and Building Technology. NBS. The AIA Research Corporation staff responsible for coordinating the research and organizing the final publicatron are; Mrchael Holtz, Project Manager and Author, Lucy Leuchtenburg. Research Assistant; and Jo Ann Masterson, manuscript typist. Massdesign Architects and Planners, inc., under sub-contract to the TABLE OF CONTENTS PAGE PAGE PAGE 9 11 17 17 20 27 30 31 FOREWORD 39 PREFACE AND ACKNOWLEDGEMENTS CHAPTER THREE SOLAR DWELLING DESIGN: INFLUENCING FACTORS lNTRODUGTlON 39 Solar Design Factors CHAPTER ONE THE EMERGING AGE OF SOLAR ENERGY 40 Climate The Given Condltlons 42 Climate and Solar Dwelling Destgn 144 REFERENCES Solar Energy An Old Idea Reborn Comfort The Desirable Condltlons 144 PHOTOGRAPH CREDITS Solar Heating and Cooling. A HIstorical Perspective 48 53 56 GulldIngs The Controlling Variable 144 BIBLIOGRAPHY CHAPTER TWO SOLAR HEATING/COOL!NG AND DOMESTIC HOT WATER SYSTEMS Archltectural Design lmpllcatlons of Solar Systems 64 Solar System Components Solar Collectors CHAPTER FOUR SITE PLANNING FOR SOLAR ENERGY UTILIZATION 64 73 81 The Site Planning Procet 5 Solar Hpat Storage Integration of the BulldIngs and Site Thermal Energy Distribution Collector-Storage-Dlstrlbutlon Component Interface CHAPTER FIVE IMPACT OF SOLAR ENERGY UTILIZATION ON TRADlTlCiNAL DWELLING DESIGN 97 CHAPTER SIX SOLAR DWELLING DESIGN CONCEPTS 141 CHAPTER SEVEN SOLAR DWELLING DESIGN: A SUNNY FUTURE? 146 CREDITS 5 INTROOUCTION The United States presently faces two interrelated problems. One, we are endangering our environment by polluting the atmosphere, ground. and water with the by-products of our technological society. Two, we are quickly running out of the fuels which have enabled uq to achieve a high standard of technologrcdi derelopment This perplexing dilemma has resulted in a nationwide investigation of energy choices. Among the many energy alternatives berng con- sidered is solar energy. Harnessing the sun’s power is con+ ’ #-.?red an attractive alternative because It IS a renewdole resource wh.ich does not pollute. In con- trast to conventional fuels, its use eliminates the need for refining, transporting, and conveying fuel and power over long distances. The use of solar energy for heating and cooling promises a more rapid payoff than other energy alternatives because the basic technology already exists and needs only minor refinements, Considerable research, development. and demonstration ar!ivities halve been initiated in the public and private sectors to facilitate the widespread utilization of solar energy. Everyday the sun showers the earth with several thousand times as much energy as we consume. The solar energy reaching the earth every three days is greater than the estimated total of all the fossil fuels on earth. In fact, the solar energy annually striking the roof of a typical residence is ten times as great as its annual heat demand. However, these figures assume a capture and utilization efficiency of 100 percent, while our present technology allows us to capture and ef- ficiently use only a small percentage of the sun’s energy. Nevertheless, the energy potentral of the sun IS great enough to warrant serious consideration and continuous development of ways to harness thus energy for man’s use. Why are we not maktng use of this tremendous source of energy provided by the sun? The answer, of course, IS that we are using it and have been for quite some time However. instead of directly using the sun’s power, we have been using stored or In- direct solar energy in the form of fossil fuels which were created by the sun and trapped In the earth ages ago and only recently reclaimed by drilling and mining. Because of industrial development dependent on fossil fuels, the costs associated with using stored solar energy became significantly less expensive than developing means to collect and utilize energy rcccived directly from the sun. However, as worid fossil fuel demand increases and conventional fuel supplies decrease, the direct use of the sun’s energy has emerged as a powerful alternative to man’s in- creasing energy and environmental problems. Although solar energy is available and free, the cap- ture and utrlizatron of It IS not. There are some very difficult technical, social and economic problems which must be resolved in order to change the ex- isting patterns of energy conversion and consump- tion. To deai with these problems, the Congress, In late 1974. enacted four laws which established a National Solar Energy Program. Overall ad- ministration of the program rests with the Energy Research and Development Administration (ERDA). ERDA and HUD have join! responsibility for the residential demonstration part of the program which is designed to Investigate the practical application of solar energy for heating and cooling of dwellings. The major elements of the National Solar Energy Program are: demonstrations of solar technology in both commercial ar,d residential butldlngs initially utilizing available systems; development of solar technology to support such demonstrations, initially using available sub-systems and components; Through these activities the major barriers to rhe use of solar heating and cooling will be identified and programs and incentives to alleviate these barriers proposed. There is, however, another stumbling block effecting the u;e of solar energy - one that thts publication hopes to remove - concerning the strong suggestion of magic or trickery Inherent with the idea that energy can be simply pulled out of thin air and sunbeams. A primary purpose of this publication is to renove the mystery associated with using the sun’s energy to heat and cool our homes and heat our water research and development of advanced heating and cooling technology; and dissemination of information The understanding of solar heating and cooling on the results of the above efforts. begins wi:h an appreciation oi the historical process by which solar energy utilization has evolved. The early uses of solar energy to power mechanical devices and to heat dwellings provide the As part of the National program. the residential dem- background from which the development of current onstration program will: efforts to harness solar energy emerge. 0 install solar systems In both new and existing dwellings; @ develop performance criteria and certification procedures for solar heating and cooling equipment; 9 undertake market development efforts to en- courage the rapid and widespread acceptance of solar heating and cooling technologies by the housing industry; and @ disseminate solar heating and coo!ing information. The focus of this publication is how the interaction of climate, comfort, buiiding sites, and solar systems influence the design of solar heated and cooled dwellings. The material is organized to illustrate and discuss these influences: first, as individual elements, and, second, as interrelated issues which affect design decisions. The emphasis of the publication is on new construction as opposed to the redesign of ex- isting dwellings for solar heating and :ooling systems. However, the major factors Tnfluencir new solar dwelling design are by and large tht ,ame as those affecting the redesign of existing dwellings for solar energy utilization. A major portion of the publication II- :ustrates a number ot solar dwelling and site design concepts. We hope that th? Ideas presented here will help to expand our knowledge of how solar energy works. how it can be adapted to our current architectural preferences, and how it may influence the shape of our homes In the future 7 ‘THE EMERGING AGE OF SOLAR ENERGY SOLAR ENERGY: AN OLD IDEA REBORN The Idea of using solar energy to heat arid cool our homes or to heat our water ;T, not new For crnturles man has made use of the SLI;I’S energy WIthout the sun’s energy manklnd cannot survive All c,ur food ;Ind ftle’ have beer1 made possible by the sun through the pho!osynthetlc comblnatlon of water and atmospheric carbon dioxide In growing pI;:nts Fuss11 fuels represprlt energy photosyntheslzed and stored In dead plant and animal matter mllllorlr of years ago The earth’s cllrndtc 15 also dependent on solar energy The winds. rides. rlvcrs and ocean currents dil rely on !he dally heat of ttle sun for their motlon Man has long mdde use of thA?se forms of solar energy He has used the wind and water cu-repts to move from place to place. and he has u;ed the sun to giovi PIIS food and VV~IIII tlls sheirer Early man knew of the advantages of flndtng a cave or placlng wall openings In the directjon of the sun’s path to zapture Its warmttl during winter days le also discovered the unique ability of certain materials to retain the sun’s *warmth aild release It later after the SUIT had set Man’s use of solar energy con- tinued and, Indeed. Increased as he became part of a tool and craft soclsty InFUllrnents which forllsed the sun’s energy to produce ilre or boil water became more sophlstlcated appllcatlons of his earlier experiences Since these simple beginnings man has continually explored new avenues of harnessing solar energy for the service of mankind. Man’s earliest attempts to harness the sun’s energy Include the fabled burning of the Roman fleet by Archimedes In 2 12 B C Archimedes reputedly set the attacking Soman fleet afIre by means of “burning glass composed of small sqllare mirrors mgvlng every \~dy upon hinges which when placed In the sun’s direct rays directed them L:pon the Roman fleet so as to reduce It to ashes at the distance of a bowshot ” ’ Reconstruct/on of Archirredes’ storied burning of an enemy fleet with a solar furnace Whether or nof Prchlmedes actually set fire 10 the salts of ttle attacking ships does little to dampen the faci that early In hlstory solar devices were being designed and i?ullt As the number and occurrence of these dsv!ces increased. man’s mythical relatlonsh!p wltL1 the sun changed Early rellglous and cultural at- titudes and beliefs towards the sun began to dls- appear and by 1600 A D. the attention of science was focured beyond superstlrlon and magic . References are presented on Fage 144 The marvelous Inventions of the Renaissance. an age of artistic and scientific revival in Europe lasting from the 14th Century A D to the 17th Century A D In- cluded many solar devices One of the most orlglnal Inventions of the period. however. was built by Salomon de Caus of France He used the sun to heat air In his solar “engine” which In turn pumped water Although a simple mechanlcal appllcatlon of solar energy. It IS remarkable In that more than two hundred years elapsed before the solar engine was reinvented The solar devices of the Renaissance were generally purposeless “qadgejs” with llttlc practical appllcatlon. other than provldlng a means of acaulr Ing knowledge about solar energy However. this trend was reversed during the later part of the 18th Century Durtnq this time solar furnaces capable of smelting Iron, copper and ether me:als were being constructed of polished-Iron glass lenses anti mirrors The furnaces were in use throughout Europe and the Mlddle East One fclrnace deslgned by rhe French sclentls+, Antoine Lavolsler. attained the remarkable temperature of 1750” C (3182” F) The furnace used a ftfty-two inch lens plus a secondary eight Inch lens to attain temperatures fat excecdtng those achieved by man up to that time and, cls It turned out, tr be achieved by man for the next one hundred years Lawmerk solar furnace Early In the 19th Century. numerous hot air engines were developed The famous Stlrllng two-piston air engine. although not designed to be operated by the sun. was ideally sulted for such use and later was adapted for solar power A curlous assortment of solar engines were built over the next hundred years. powering everythlng from prlntlng presses and elec- trlc lights to dlstlllatlon operations Sd~r unwered pr/nr/ng press ar Pans Worlds Far 1889 One unique varlatl,)n which occrrired durtng the late 1800’s and early 1900’s was the use of “flat-plate” collectors to lntarcept the sun’s rays and power equlprnent Ur,til :hl< rlrne most so!ar devices used what IS called a “focustnp” collertnr ~~~ one tha! iocuse.j the sun’s rays upon a single area where the energy IS collected The “fiat-plate” type collector, however. does not focus the sun’s rays to a single point but collects the solar energy over a uniform horizontal surface Flat-plate collectors had the ad vantage of belny less expenstve and simpler to con- struct and opern!e than the focusrng type collector Also. whereas focuslnq cnllectors require clear skies for operation. flat -plate collectors could function ~111~ der cloudy cOndltlOnS Several solar powered yurrl- ping facllttles were constructed during the early 1900’s In the Unlted States which Illustrate both forms of solar collectton A G Eneas In 1901 Installed a thrtythree foot dtameter focusing collector whlrh powered a water pumping apparatus at a Pasadena. Callfornla ostrich farm The device conslsted of a large umbrella-Iike structure open and Inverted at an angle to receive the full effect of the sun’s rays on the 1.788 mirrors whfch lined the InsIde surface The sun’s rays were concentrated at a focal point where the holler was !>cated Water wlthln the holler was heated to produce steam which In turn powered a conventlonal compound engine and centnfugal pump Dunng the next 50 years many vanatrons of this process were deslgned and constructed using focusing collectors as the means of heating the transfer or working fluid which powered mechanlcal equtpment The Pasadena sumhear absorber of 1901 Frank Shuman. an inventive engineer. however, fowled iiie more economical flat-plate collector Us- ing twelve hundred square feet of collector area. his test engine produced 3 5 horsepower The flat-plate collector. constructed In 1907. was used to heat water which. In turn, boiled ether The ether vapor was then used to drive a vertical steam engine which pumped water Although Shuman’s sold: engine did not develop dnythlng near the 100 10 Shuman’s flat-plate collector and pumping operavon horsepower predicted. In part due to the polluted air and cloudy conditions of Tacony. Pennsylvania. the process and technique of collecting and utlllzlng solar energy were slgnlflcantly advanced Despite the Increased sophlstlcatton and reliability of solar powered devices. none of these early appllcatlons of sclar energy survived competltlon wtth the emerging use of cheaper fossll fuels For although solar energy was free and readily avallable. the capttal Investment was so high for the necessary solar collectors and associated equipment tt,dt It cost much rnore to run a solar engine than a con- ventional type For hundreds of years man has attempted to harness the sun’s energy After slowly accumulating know- ledge about the nature of the sun’s energy and developtng a simple technology to capture tt, solar pioneers came sup against the most frustrating of roadblocks - the apathy of ttlelr fellow man However, the completely different energy and en- vironmental sltuattcn which we now face has made solar energy ar. Idea whose time has come and gone - and come agaln - this time to stay SOLAR HEATING AND COOLING: A HISTORICAL PERSPECTIVE Dwellings which nave used the sun’s energy to heat or cool have been constructed for thousands of years Although perhaps inmally stlmclated by a necessity for survival. solar dwelling design has become an expression of man’s attempt to harness solar energy for his benefit and advancement The marvelous tools and devces lust discussed are testament to man’s Intellectual curiosity and unceas Ing quest for knowledge abcut the world around him Using solar energy to incrnase crop VIeIds. to power needed mechanlcal equipment. to heat and cool bulldings and to heat water IS a natural progression of an intellectually rest&s rnan fascinated with the sun Intuitively. man’s dwellings have responded to the beneflclal effects of proper building exposure to the sun and lccal climatic condmons Indigenous Amerlca;l Indian and colonial drchitecture -- the Pueblo structures of the Southwest and the Nti\v England “s;!libox” -- are both good examples of dwelling; responsive to the demands of sun and climate The Pueblo Structures of the Southwest The ilot-and climate of the Southwest IS character- Ized by high daytime temperatures and uncomfor- tably low ntghttlme temperatures The solution best sulted to such a wide temperature fluctuation IS delaying the entry of heat as long as possible so that tt will reach ttie Interior late In the day. when It IS needed The Pueblo Indians achieved this desired Taos pueblo. New Mexico. therrnal performance by using materials of high heat capacity. such as adobe. mud and stone tiblch provide a “heat sink.” absorhng heat from the sun during the dav and reradlatlng !t Into the dwelltny during the night Also by crowdlng their dwelllc3 spaces togtther. side by side and one on top of another, the Pueblo’s achieved maxlmum volume with the mInImum su:face area exposed to the out- side heat. thereby reducing the area exposed to the sun while Increasing the mass of building as a whole, thus increasIng the thermal time-lag * Another Important conslderatlon for hot-arid climates IS to avoid Interior heat build-up during the day The Pueblo’s accompllshed this by separating the cook- In4 space from the llvlng spaces, bv reducing the number and size of windows and placlng them high on walls to reduce radlatlon gain. by palntlng the dwetilng white or r,ome other light color to reflect a maxlmum of radla:lt heat, and by mlnlmlzlng ven- tllatlon during the hottest portlon of the day A untque example of these prlnctples pf solar desgn 1s to be found In the cliff dwellings of the Slnaqua and Anasazl Indians In Arizona The cliff dv,elllngs. called Montezuma’s Castle. built in 1 100 A D made Montezuma’s Castle. 1100 A D l Thermal Time Lag IS a time function relating to the transfer of heat through a material Section Detail N Thick Adobe Walls - Small Openings use of the heat capacity of mud, rock ;Ild other In- digenous materials to absorb dtr?ct solar radlatlon on the south facing ,vertlcal walls The heat was then rerad!a?ed ?o the In!er!er spaces during the evening The compactly grouped dwellInns were light In color and had small wall openings to reduce direct and reflected radlatlon heat gain The cliff dwelllnq also had one tnterestlnq feature which dIstInguIshed It from the Pueblo structures of the surrounding area Recanse ihe dwell~r~qs we-e built under an extended portlon of the mountain. the overhang blocked the high summer sun, thereby providtng natural coollnq !or the dwellings The New England “Salltbox” A!though there are dtfferent degrees of cold, both In duratlor! and Inte,- ‘1, the prlnclples of keeping warm are the same ana are related closel; to those ,. ^., ture heat given off by cooklng and space heattng Reducing heat loss IS achteved by a compact plan, a mInImum surface area exposed to the outslde. rnaterlals of good Insulating CharacterIstIcs and the prevention of drafts and air leaks Also, by sloping the rnof on the north side of the dwelling toward the qround. shelter frorn the wind and a reduction of surface area exposed to the cold IS achieved This allows snow to build up on the roof and thus further to Insulate the dwelling frorn heat loss Another difference from hot-arid areas IS the destre to cap- ture as much soiar radlatlon as possible during cold wedther Therefore. the wlndowed two-story portlon of the dwelling faces south and the dwelllnq IS painted a dark color (dark colors absorb more solar energy than light colors) Pueblo and colonial archltectutti are representative of the Intultlve responses to local climatic condltlons and the heneftclal effects of proper h ,:ldlng r.xposure to solar radtatlon that were develop! ,I ‘. -, I“V parts of the world The lntultlve approach B :-I ,: heating and cooling has lald the ground wo!: :r, ; which a sclentlflc understandlng of solar radS.‘:.llr r id its cor- responding climatic Impact on hulldtng has recently develooed Crysfa: Horise. Worlds fa/r ‘934. Chica,& ////no/s collect store and dlstrlbute solar energy as a prlnci ple heat source for human comfort The Crystij! House at the 1933 Chlcago World’s Fair IL c:ltc?d as an early example of the direct “qrc:enhollsr:” effect whereby glass wzlls or wtndows were used JS heat collectors George and Wllllani Keck. architects for the Crystal House. began to Incorporate the Ideas developed from th’s design Into other dwellngs Their designs used large expanses of south facing glass which allowed the low winter s*.ln ‘0 hoar the Interior masonry floors asld wails cf the buildtng dur lng Ihe day (In much the same way as the Pueblo structures!. which In turn radiated the stored heat to the spaces durinq the evening A reporter for the Chicago Trtbune began to describe houses with these features as “solar houses” and since that time there has been a rekrndlrng of In terest In usrng the sun’s energy to heat and even cool burldrngs The houses burlt by M I T as part of the Cabot Solar Energy Conversron Project between 1939 and 1956. and the Peabody/Raymond/Telkes house bull: Ii1 1949. were the frrst fully documented solar dwellrng designs where a major portron of the heat re- qurrement of a dwelling was obtained by a formal solar collector and storage system In the case of t!-1e latter, the entrre heat requtrement was obtained by solar collector and storage systems In all. f[JUr solar-heated dwerr!ngs wt?re hurlt by M I T The frrst two burlt In 1939 and 1947 were MI T Solar Home No 3. Camhndge. Massdchuretts more experrmental laboratorres for evaluatrng solar equrpment than actual dwellrngs for famrfy lrvrng The third dwellrng, remodeled In 1949 from the shell of the second. however, was desrgned to house a student family wnh one chid The solar heatrng system consrsted of a south-facing flat-plate collector mounted on the roof wtth a large water storage tank located directly behrnd It. Solar radratron. collected by water clrculatec! through the flat-plate collector and drstrrbuted by copper tubing mounted In the cerlrng. provrded for more than three quarters of the dwellrng’s heating load. The large wrndows along the south wall of the dwelling provided heat rn excess of need for several hours of the day in sunny wrnter towards the south and covered wrth two panes of weather and as a consequence had to be released qlass Water was heated by the sun as 11 crrculated bv vcntriatron D:~r~ng the hot sumnltir fnL)r-tih> through the collector dnd was stored In a 1.500 however the south facing wrndows were shaded by qallorl insulated storage tank located In :he an overhang b,jscment Heat from the water storage tank was rrdnsfe:red to arr by a heat exchanger and drsrrrbured rhroilohour the house bv blower ,lnd d11c ts This - -. -. Telkes Raymcx~tl’ Peahod\ Hoose Dorcr A.Yilssachti.sc~ri.\ Also durlngl 249 d solar heated hoilsr, was blcl!t 111 Dnvrr Massachusetts Independent :,f thn M I T 5oldf housing program The house wds enqlne?rtrc:d desrgned rind sponsored by the Mrsses Telkes Rrlymond and Peabody respectrvely The: ma~nr oh fectrves were to prove II-,e feaslbllrtv of cnmplrte solar heating ;n the Roston area desprtc thij chance af three to five consecutrve sunless days WII~ no cuilectron. ana to demonstrate the merits oi usrng the heat of fusron of Gtauber salt’ as a means of storrng heat The dwelling used both south facrnq wrndows and vertrcal collectors to capture direct and ref!ected soiar radratton from the lsw winter sun The hot air removed from the solar collectors was used to heat five gallon storage cans frlled with Glauber salts When heat was needed, arr was circulated around the cans by small fans, heated and drs trrbuted to each room The technIcat feasrbllrty of total solar heating In the Boston area and the use of the heat of fusron of Glauber salt as a storage medrum were both adequately demonstrated by the Dover house The fourth and frnal solar house built by M I T under the Cabot Foundanon Project ‘was constructed In 1956 at Lexrngton. Massachusetts The house had both solar space heatrng and solar domesttc water heating The dwelling used a flat-plate collector tilted * See Page 29 fc,r more detalled mformatron ~~ -D y-g= .,- - _-b-- _ M / T Solar Hnr~se No 4 Lexington Z/la.s.~at:h~lse:ts Wrth the exceptron of an astrve. but relattvely un heralded cornmunrty of solar researchers who built upon the M I T work. an Interruptron of almost 10 to 15 years occurred In the applrcatron of solar technology to burldIngs Two notable exceptrons are the work of George Lof and Harry Thomason George Lof. a chemrcal engineer from Denver, Colorado. who has been Involved In solar energy research and apptrcatrons srnce 1944, constructed a solar house In Denver In 1957 The solar heating system. which IS stall In operatron. consrsts of two arrays of south-facing flat-plate collectors and two vertical storage cyltnders filled wrth granrte rock A blower draws air through the rooftop collectors to the storage cyttnders and drstrrbutes the heat through floor ducts to the tndrvrdua! rooms 13 Ldf House. Denver. Colorado Domestlc hot water IS preheated by running the hot water piping through the IncomIng heated air duct from the collectrr Harry Thomason, a lawyer from Washington. D C constructed three solar dwveiiln?s In the Washington area between 1959 and 1963 A slmllar solar energy system IS used In each dwelling The collec- tor IS made of blackenL c:nrrlugated aluminum covered wtth a single pane of g!ass p!aced on either a sloping roof or wall facing south or slightly west of south Solar radlatlon IS collected by water “trlckllny” down the open channels of the corrugated aluminum The heated water 1s transferred to a storage tank surrounded by fist-size rocks The rocks which are heated by the water In the tank provide an addItional storage media and the mechanism for transferring the heat from water to air To heat the Thomason Solar House No 3. Washmgton. DC house. air IS drawn from the house through the rock bed. ptcklng up heat frotr, the tar& dnd rocks and blown through ducts Into the lndlvlduais rooms Thomason’s last two solar dwellings have Incor- porated a compresslon refrlgeratlon system for cool- ing Operated at night. the system chills air which cools the rock storage for dlstrlbutlon during the day Early In the 1970’s. the econom!c and environmental cost of conventlonal fuels brought attention back to solar energy as an alternative energy source for ilcatlng and cooling Although the earlter solar houses at M I T and Dover have all mr?t various fates (they are either demolIshed or arc operating without their solar equipment) they nonetheless proved that solar heating was possible with exlstlng technology Gtven sustalned technical refinement. ap propnate archltectural design. and industry and marketing economies. solar energy could possbly become a major source of energy for the heating and cooling of bulldings The concerns of solar designers II: the early 1970’s were practical .~- “plumber’s work” as It IS called ~~ In contrast to the theoreilcal research conducted and refined during the pre\iiotis three decades In !he last five years. the number of operating solar dwellings has Increased to approximately sixty Although this amounts to a mlnlscule percentage of the total United States housing market, tt does represent an Increasing energy. economic and environmental awareness Addltlonaliy the growing numher of solar dwelllnys reaffirms the feaslblllty of solar heating and cooling with exlstlng technology The solar dwellings built over the last several years range from those that require no mechanlcal equlpment for their operation to one which generates its own electricity from solar energy as well as coilectlng and storing radiation for heating and coolmg. The following solar dwellings built between 1972 and 1974 represent a variety of solar dwelling designs lllustratlng different ways of collec- tlng. storing and dlstrlbutlng solar energy for space heating and cooling and domestlc water heating rhe first example, the David Wright residence of Santa Fe. New Mexico. built In 1974. Illustrates a modern adaptation of the Pueblo lndlan structures The design IS extremely simple and opera 011 first II)- spectlon the only “collector” vlslble IS a 32 square foot solar water heater on the ground. and some might questlon the use of the terminology “solar dwelling ” However. the sun dictated the desgn of the house from the very begInnIng The solar aspects are so well Integrated :hat the house actually becomes the solar collector and the heat storage system The south wall of the house IS constructed Dav/d Wright House. Sante Fe. New Mexfco entirely of Insulating glass and serves as the snlar heat collector Adobe II, the exterior walls and beneath the brick floor provides heat storage by ab- sorbing Incident solar radiation Several 55 yailon drums filled with water are burled beneath an adobe banco along the south wall to provide addItional hedt storage insulation IS located aroulid the en- tire outside of the adobe walls. and beneath the adobe floor The lnsulatlon mlnlmlzes the flow of heat from the walls and floor to thr: colder outslde air and the ground Thus the heat IS stored until the temperature Inside the house drops and then the stored heat IS radiated and convected into the space The fabric of the building IS capable of storing enough heat to keep the home comfortable for three or four sunless days The solar house of Atascadero. Callfolnla. Illustrates another variation In solar ccllectlon and storage design The Atascadero solar house uses horizontal water ponds (In plastic bags) located within the roof structure for solar collectlon. storage. and distrl-