South-facing Windows Research Articles

Daylighting performance of an electrochromic window in a small scale test-cell

In this paper, the results of an experimental investigation aimed at assessing the performance of electrochromic (EC) windows with respect to daylighting control in buildings are presented. The research is performed under real weather conditions by a small scale test-cell equipped with a small area double glazing unit (DGU) where one pane consists of an EC device with visible transmittance τ v ranging from 6.2 to 68.1% and the other of an ordinary clear float glass ( τ v ≈90%). Experimental tests are carried out as a function of time, weather conditions, test-cell orientation and switching strategies. These data are integrated with spectrophotometric measurements. Results show that the angle selectivity of the glazing combined with its active switching effect allows a wide range of selectable transmission states to suit the latitude and orientation of a building in relation to the local climatic conditions. For south facing windows and under the involved climatic conditions EC glazing driven by a dynamic control strategy can be very effective in reducing discomfort glare caused by high window brightness. Glare reduction can be realized contemporarily maintaining the work plane illuminance to adequate level for computer based office tasks so without compromising much of the available daylight. Furthermore, since EC glazing is never switched to heavily darkened states ( τ v >20%), colour rendering of inside objects should be always acceptable, although internal illuminance level could be slightly lower than to what users prefer in relation to the correlated colour temperature of the incoming light. These results change when considering west orientation for which high-luminance direct sunlight patches are registered on the work-plane even for EC glazing switched to its lowest transmitting state letting suppose that EC windows cannot provide full control of uncomfortable direct sunlight effects without integration of additional shading devices.

Effect of switchable glazing on discomfort glare from windows

In this paper we report the results of experimental tests carried out to study the effect of electrochromic (EC)-glazing on discomfort glare from windows. The research is performed by a small scale test-cell equipped with a small area double glazing unit (DGU) where one pane consists of an EC device with a visible transmittance τ v ranging from about 7 to 70% and the other of an ordinary clear float glass ( τ v ∼ 90%), the overall DGU transmittance dynamic range resulting about 4–58%. The performance of the device is investigated under real sky conditions as a function of time, solar radiation intensity, test-cell orientation and switching strategies (static and dynamic). The evaluation methods adopted for assessing the discomfort glare degree are the “New Daylight Glare Index” (DGI N) and the “Glare Subjective Rating” (SR). Results deriving from application of these two methods are compatible and show that for south facing windows and under the involved climatic conditions EC-glazing can be very effective in reducing discomfort glare caused by high window brightness originating from diffuse skylight. This glare reduction can be realized without compromising much of the available daylight so without necessarily increasing the need for artificial lighting and, at the same time, preserving an unobstructed outside view. Occurrence of glare effects from west (or east) facing windows is more difficult to be controlled due to the lower sun angles which entail the use of EC devices switchable to very low transmittance states ( τ v < 7%) and/or integration of traditional sun protection devices. This would probably compromise indoor daylight availability (and potential energy savings associated to reduced use of artificial lighting) as well as exterior view although the positive effect of the EC-glazing could be a substantial reduction of the frequency of use of these additional shading systems.

Bringing Green Homes within Reach: Healthier Housing for More People

Gaze upon the Helliers’ half-built house in Bristol, Vermont, and you might think you’re looking at an ordinary home construction project. Table saws, building materials, and piles of earth lie around the newly framed dwelling, while a crew of carpenters mills around the site, dressed for warmth in the chilly fall air. But look closer, and some unique features emerge. The exterior frame is wrapped in an outer layer of heat-trapping insulation. Sunshine streams in through large, south-facing windows, flooding the interior living spaces with light. Once the house is completed, solar panels will supply the family’s hot water and much of its electrical power. And indoor finishes, paints, rugs, and fabrics will be nontoxic. In short, the Helliers’ house is being built to be green. And that puts it in good company; new green homes jumped in number by 30% between 2005 and 2006 and could include up to 5% of the entire U.S. housing market within five years, predicts McGraw-Hill Construction, an industry information provider, in its June 2006 Residential Green Building SmartMarket Report. That makes green homes bright spots in an otherwise dismal housing market facing its worst slump in decades. To everyone’s benefit, green homes link sustainable materials and practices with better human and environmental health. “You’re really looking at a tripod of components,” says David Johnston, president of green building consultancy What’s Working and author of Green from the Ground Up, a forthcoming book on sustainable residential design. “First, energy efficiency has to be above minimal code requirements for your climate. The second component has to do with improved water and resource efficiency, and the third concerns indoor air quality. If your design doesn’t address all three of these issues, then you don’t have a green home.” According to the U.S. Environmental Protection Agency (EPA) Office of Air and Radiation, indoor air is typically 2–5 times more polluted than outdoor air, owing to the presence of asthma-inducing agents such as mold and toxic chemicals in carpets, paints, and other synthetic materials. In fact, the EPA ranks indoor air as one of the top five human health risks, says agency spokesperson Dave Ryan. By requiring nontoxic materials, green designs limit indoor exposure to carcinogens such as formaldehyde in manufactured wood products including sheathing and particleboard, and to volatile organic compounds (VOCs) in finishes. Home energy uses also contribute to global warming. The Energy Information Administration (EIA) in Washington, DC, estimates that domestic power demands account for 21% of all the greenhouse gases emitted in the United States. The construction industry as a whole accounts for 48% of U.S. greenhouse gas emissions, according to advocacy group Architecture 2030. And by optimizing insulation, green designs save on oil and gas bills, which are (quite literally in poorly insulated homes) going through the roof. But even as green homes gain in popularity, they’re also dogged by a sticky association with the rich, seen by many as too pricey for ordinary buyers. Indeed, McGraw-Hill Construction identified cost perceptions as a top obstacle to green building among homeowners and builders alike. Fueling that preoccupation with cost is a media obsession with “eco-mansions,” laments Charles Lockwood, a green building consultant in Los Angeles and New York. “Most of what you see in the press would leave you thinking you’d have to live in Malibu or Aspen to afford one of these places,” he says. To wit: the Maine Sunday Telegram in Portland ran a feature on 4 November 2007 titled “Unaffordably Green?” about a $1 million ultra-green home in nearby Freeport that was unsold after a year on the market. Christopher Briley, an architect with Green Design Studio in Yarmouth, Maine, concedes that most people who build their own houses have above-average incomes (McGraw-Hill Construction’s SmartMarket Report shows that nearly two-thirds of those who buy green homes make more than $50,000 a year). And buyers with more money to spend, Briley says, are apt to mix green design elements in with a host of other more expensive features—radiant floors and granite countertops, for instance—that skew costs higher. “A lot of these houses are going to be expensive anyway,” he says. “But that doesn’t mean you can’t have an affordable green house. It’s all about where you decide to spend your money.”

Design optimization of solar cooker

Various designs of solar cookers have been theoretically investigated with a view to optimize their performance. Starting from a conventional box type cooker, various combinations of booster mirrors have been studied to arrive at a final design, aimed at providing a cooker, which can be fixed on a south facing window (for countries of northern hemisphere, mainly situated near the tropic of Cancer). This cooker, with a rear window opening, may provide higher cooking temperature for a fairly large duration of the day. Two or three changes in positions of the side booster mirrors, without moving the cooker as a whole has been proposed. The new design has been experimentally implemented and compared with a conventional box type solar cooker. Besides the convenience of a rear window opening, the cooker provides temperatures sufficiently high to enable cooking two meals a day.

Monolith Makeover: The Art of Subversive Urban Enhancement

Recently, I was in a tall building in downtown Toronto with a panoramic south-facing window. I stopped for a minute to gaze at the endless stream of automobiles flowing along the Gardiner Expressway. As I spied on the concrete arteries bringing travellers to and through the city’s heart, my own heart bubbled over with memories of our summer fling. Suddenly, I felt like the heroine of a Hollywood movie contemplating a past lover from a distance with tenderness and passion. I was haunted by romantic recollections of the fleeting artistic relationship I had enjoyed with this highway. In the universe of site-specific installation and performance, the physical evidence of work may fade or vanish after minutes or months, but the memories, as they say, linger on.

Thinking in Circles

“Oh my God,” the man says. He is about 70 and balanced on one foot in our doorway, trying to remove his left shoe while staring across the round room. He teeters a little, leans back against a wall, and smiles. “Will you just look at that?” Releasing his foot, he is oblivious of everything except the view through an arc of south-facing windows, “If I lived here,” he whispers,“I’d never get anything done. I’d just watch the woods.” He is at our house to see and, we hope, to buy Beverly’s art. For two weekends every October, we turn our tiny, cedar-sided yurt into a gallery, hanging about a dozen paintings on the walls, mounting several more on small easels here and there, perching others against boxes on the kitchen counter or against the credenza on the living room floor. She is a painter of landscapes and still lifes, mostly in oil, the work informed as much by her early training in geology as by her later study of Impressionist styles and her spiritual practice. These six days in mid-autumn, during the countywide Art Harvest Open Studio Tour, our home is taken over by the rich colors, forms, and textures of her work. And we open our isolated, normally tranquil place to all comers. That can be a deeply unsettling experience. We have only 615 square feet of circular space to work with, much of it glass, so it feels as crowded as the lobby of a concert hall at intermission. We bake banana bread and muffins, and I sit at the dining room table with an emptied tackle box to collect checks, a receipt book, and a price list. Thinking in Circles

Circadian Rhythms in Limulus Visual Sensitivity Compensate for Day-Night Changes in Light Intensity

At night a circadian clock transmits efferent optic nerve activity to the lateral eyes of Limulus polyphemus, increasing their sensitivity to light. The animal’s use of vision to find mates at night suggests that the clock’s effect on retinal sensitivity compensates for the nighttime decrease in ambient illumination. To test this possibility we recorded activity from optic nerve fibers in situ while the animal was exposed to day-night changes in illumination in its natural environment. Using a waterproof recording chamber we monitored the maintained activity of single or small clusters of optic nerve fibers. Placing an animal at a meter depth near the shoreline of Woods Hole, Massachusetts, enabled us to monitor optic nerve activity with a remote amplifier and recorder connected to the animal via a tether. A single optic nerve fiber typically responds to ambient daylight illumination at rates ranging from 4 to 14 impulses/s. In one experiment the steady-state firing rate was 4.7 ips in the early evening when the ambient intensity was 85 cd/m 2 . At 8 p.m. the rate increased to 9.2 ips as the light intensity decreased to 0.054 cd/m 2 . The rate was 11.8 ips under bright illumination the following day (22,000 cd/m 2 ) and dropped to 5.3 ips at 0.040 cd/m 2 that night. Similar results were recorded from animals that were placed in an aquarium next to a south-facing window in Woods Hole. The nearly 1,000,000fold decrease in ambient illumination at night appears to be associated with only about a two-fold decrease in optic nerve response. We conclude that the circadian clock’s input to the lateral eye nearly compensates for the diurnal changes in light intensity. Supported by NSF, NEI, NIMH, RPB and the Lions of Central New York.

Exergy analysis of a low temperature radiant heating system

The purpose of this study is to gain insight into the process of heating a room with a low-temperature radiant heating system and solar energy, considering energy conversion and heat transfer steps in the building (where heat is required), in the incident solar radiation (which supplies part of the heat required) and in the heating system (which provides for the additional heating needs, by using electricity from a gas-fired power plant to drive a heat pump). We applied a theoretical framework developed by Shukuya et al., to a dynamic simulation model and did numerical calculations for a room with an exterior wall, with and without a south-facing window, during a heating season in the Netherlands. The exergy analysis allows direct comparison between different energy types (e.g., heat, electricity, fuel) on a common basis, and the concept of exergy consumption is useful for expressing how and where energy is dispersed in the course of energy conversion and heat transfer steps. The results show that exergy consumption in the room (demand side) is relatively small compared to the supply side (fuel burned at the power plant and the sun reaching the ground and facade). The calculations also show that the total amount of exergy consumed during the heating season can be larger than the total amount of exergy supplied during the same period, as a result of heat storage in the building mass, and of changes in the outdoor temperature between the moment of heat storage and heat release.

Reversible post-exposure yellowing of weathered polymers

The commonly observed effect of weathered polymer samples continuing to change color in the dark was studied in some detail for polycarbonate, styrene–acrylonitrile copolymer (SAN), and various combinations with SAN–polybutadiene rubber graft (SRG) copolymer. All of the formulations became more yellow upon storage in the dark after accelerated weathering, and all behaved very similarly. There was a fairly rapid shift of 1–2 b units (as defined in CIELAB color space) over the first two weeks followed by a slower, linear shift that continued for many months. This amount of color shift is enough to be visible to the eye in side-by-side comparisons. Most of the additional color generated in the dark could be bleached by exposing the samples to sunlight through a south-facing window. The samples usually reached the original color after 2–4 days of window exposure. Putting the samples back in the dark caused the yellowing to start up again, although the rapid yellowing often was not as much as the first time. Samples aged under natural conditions outdoors also underwent a small color shift upon storage for 5 months and substantial color shifts after two years. The results are consistent with the photo–thermal equilibrium between Z– E isomers as suggested in the literature, although some aspects remain unexplained.

Reversible post-exposure yellowing of weathered polymers

The commonly observed effect of weathered polymer samples continuing to change color in the dark was studied in some detail for polycarbonate, styrene–acrylonitrile copolymer (SAN), and various combinations with SAN–polybutadiene rubber graft (SRG) copolymer. All of the formulations became more yellow upon storage in the dark after accelerated weathering, and all behaved very similarly. There was a fairly rapid shift of 1–2b units (as defined in CIELAB color space) over the first two weeks followed by a slower, linear shift that continued for many months. This amount of color shift is enough to be visible to the eye in side-by-side comparisons. Most of the additional color generated in the dark could be bleached by exposing the samples to sunlight through a south-facing window. The samples usually reached the original color after 2–4 days of window exposure. Putting the samples back in the dark caused the yellowing to start up again, although the rapid yellowing often was not as much as the first time. Samples aged under natural conditions outdoors also underwent a small color shift upon storage for 5 months and substantial color shifts after two years. The results are consistent with the photo–thermal equilibrium between Z–E isomers as suggested in the literature, although some aspects remain unexplained.

井戸水を用いる天井放射冷房の実測とそのエクセルギー解析

The purpose of this study is to utilize the concept of exergy to discuss the meaning of well water 'coolness' applied to a ceiling radiant cooling system. A house in Chiba was equipped with a ceiling radiant cooling system using well water, and with outdoor sun-shading on the South-facing window. We conducted measurements of indoor thermal environment and electric power consumption in the summer of 2001. The results showed the following : 1. The ceiling radiant cooling system consumed cool thermal exergy from well water and emitted a small part of it as cool radiant exergy from the ceiling radiant panel surface. 2. When cooling system was used, not only the ceiling radiant panel but also the surrounding walls and floor contributed to the radiant cooling effect by emitting cool radiation exergy. 3. The well water pump consumed about 56 times more exergy than the ceiling radiant panel and the circulation pump consumed about ten times more exergy.

自然室温による日本各地の戸建住宅の熱性能評価に関する研究

This study proposed a evaluation method of the thermal performance of detached houses using natural room airtemperature. The numerical simulations were performed to clear the effects of techniques such as wall insulation, multiple glazing, south-facing large windows and air tightness of the house as well as summer solar shading and natural ventilation on the natural room air temperature. The scheme of high-performance houses that exceed the assumed criterion of the natural room air temperature were presented for 10 cities in Japan.

Indoor Climate of an Open-plan Office Building Having the South-facing Large Window Designed with a Conception of &quot;Semi-passive Control&quot; : Part 2-Performance Measurement of Ventilation System by Age of Air

Indoor Climate of an Open-plan Office Building Having the South-facing Large Window Designed with a Conception of &quot;Semi-passive Control&quot; : Part 2-Performance Measurement of Ventilation System by Age of Air

Indoor Climate of an Open-Plan Office Building Having the South-Facing Large Window Designed with a Conception of &quot;Semi-Passive Control&quot; : Part 1-Description of the Building and Measurements of the Ventilation Air Volume, the Airtightness and Long-Term Fluctuations of Temperature and Humidity

Indoor Climate of an Open-Plan Office Building Having the South-Facing Large Window Designed with a Conception of &quot;Semi-Passive Control&quot; : Part 1-Description of the Building and Measurements of the Ventilation Air Volume, the Airtightness and Long-Term Fluctuations of Temperature and Humidity

Empirical validation of building energy simulation programs

The largest-ever exercise to validate dynamic thermal simulation programs (DSPs) of buildings has recently been completed. It involved 25 program/user combinations from Europe, the USA and Australia, and included both commercial and public domain programs. Predictions were produced for three single-zone test rooms in the UK. These had either a single-glazed or double-glazed south-facing window, or no window at all. In one 10-day period the rooms were intermittently heated and in another 10-day period they were unheated. The predictions of heating energy demands and air temperatures were compared. The observed interprogram variability was highly likely to be due to inherent differences between the DSPs, rather than the way they were used. Predictions of the difference in performance of two rooms were no more consistent than predictions of the absolute performance of a single room. By comparing the predictions with the measurements and taking due account of experimental uncertainty, the DSPs that are likely to contain significant internal errors are distinguished from those which, in these tests, performed much better. The likely sources of internal error are discussed. It is recommended that empirical validation exercises should consist of an initial blind phase in which program users are unaware of the actual measured performance of the building, and then an open phase in which the measurements are made available. The work has produced five empirical validation benchmarks, which have significant practical benefits for program users, vendors and potential purchasers. There is considerable scope for improving the predictive ability of DSPs and so suggestions for further work are made.

Reading Agnon Through Agnon: Creating the Legend of the Inspired Genesis of Fiction

Reading Agnon Through Agnon READING AGNON THROUGH AGNON: CREATING THE LEGEND OF THE INSPIRED GENESIS OF FICTION by Stephen Katz Stephen Katz is Associate Professor of Modern Hebrew Language and literature in the Department ofNear Eastern Languages and Cultures, Indiana University, Bloomington. He is also a member of the university's Jewish Studies Program and the Middle Eastern Studies Program. He is currently completing a study on the evolving fiction ofS. Y. Agnon. --------------27 Visitors dropping in at the Agnon House in Jerusalem's Talpiot neighborhood seem to seek that measure of experience which would concretize for them what the nation's greatest author was like. Shown its interior; they try to imagine what the ground floor must have looked like when many rooms filled the space now occupied by a single large public space. Screening a video documentaryfeaturing the great author commenting on his work and life and guiding the viewer to his library, the audience becomes accustomed to the cadences and peculiar intonations ofAgnon's voice. Undoubtedly, the high point of each visit is the guided tour of Agnon's work-room and library, still intact and containing some ten thousand volumes, occupying three rooms upstairs, where the author spent much of his life composing some of the greatest works of Hebrew literature. Many of the newer books bear autographed dedications to Agnon by authors great and less so while dark and ancient volumes still hold slips of paper, book-marks, left there by Agnon.1 'For samples ofauthors' dedications to Agnon in books sent to him, see Tzvi Kaspi, "Mar Shai 'Agnon hayakar" [Dear Mr. S. Y. Agnon], Ha'aretz (March 5, 1993), p. 6. For sample dedications of books by Agnon to others, see Yol:Ianan Arnon, U'Agnon behakedashotav (bimelot shalosh shanim liftirato)" [Agnon's dedications: Three years following his death], 28 SHOFAR Winter 1996 Vol. 14, No.2 Left to the eye is a view of the author's work-room, its walls lined with bookshelves rising to the ceiling. In the center, by the south-facing window, stands his desk. Often missed is a glance into a small wooden box on that desk, one containing white slips of paper which were used as the author's book-marks and notes to himself and others. In the summer of 1986, the topmost slip in that box bore a pencilled note in the author's unique hand which read, in Hebrew, "Bakhlam=Klausner." Readers of Agnon's writings will easily recognize this as a reference to a character in his novel Sbira2 in which Professor Bakhlam appears to have been fashiuned after Professor Joseph Klausner, the celebrated scholar of Hebrew literature and Jewish history, who was also a neighbor of the Agnons.3 The candor contained in that slip of paper, ~nd the way it represents Agnon's process of creation of a figure in a novel, are largely unavailable to the contemporary student bent on investigating this author's writing habits. While much ofAgnon's archive is accessible for such perusals, it too Yedi'ot 'a1;Jronot (February 23, 1973). Regarding the mutual admiration and reciprocal dedications carried on byAgnon and Bialik, see Hiam Be'er, Gam 'ahavatam gam sin'atam: Bialik, Brenner, Agnon ma'arekhot-ye1;Jasim [Their love and their hate: H. N. Bialik, Y. H. Brenner, S. Y. Agnon-relations) (Tel Aviv: Am Oved, 1992), pp. 197, 200, 288, 293, 298, and more. I wish to acknowledge and thank the assistance given me at the Agnon Archives, situated at the]ewish National and University Library at the Hebrew University ofJerusalem, and by its director, Mr. Raphael Weiser. The availability of the archival resources and the readiness with which Mr. Weiser and his able staff stood to be of help in all matters, have made a significant part of the following observations possible. 2S. Y. Agnon, Shira Oerusalem and Tel Aviv: Schocken, 1971 and 1979); English version, Shira, trans. Zeva Shapiro (New York: Schocken Books, 1989). ~Agnon lived on 16 Klausner Street, the name bearing tribute to the famous scholar whose home stood near the Agnon house, facing it across the street. Corroborating the identity of Professor Klausner with Bakhlam is G...

ドライエリアを付設した半地下居室の熱環境性能 : 数値計算による分析と自然室温状態での長期実測

In order to obtain fundamental information on thermal performance of a semi-underground room with areaway, long-term measurement for a twin-type test house on the campus of Tohoku University was made under the situation without auxiliary heating during 18 months from Dec., 1990 to May, 1992. This paper reports the measurement results and discusses thermal effect of the area wayby comparison with results conducted from previous measurement for the test house without the areaway. Results of computersimulations using a two-dimensional finite element program are also discussed. Main findings obtained by the measurement and the simulations are summarized as follows: 1) From viewpoints of stability of room air temperature and energy conservation for heating and cooling, the thermal performance of a semi-underground room with south-facing large window and areaway is not so regardful because of greater heat gain and loss through it. 2) However, if the areaway is covered with glass during heating season, it is estimated that the performance becomes better.

Five-year measurements of thermal performance for a semi-underground test house

Abstract In order to obtain fundamental data on the thermal performance of a semi-underground room, a twin-type test house was constructed on the campus of Tohoku University in September 1984. The test house has two rooms with south-facing windows above the ground surface, and a corridor between the two rooms. The floor level is 1.3m below the ground surface. Thermal insulation 0.1m deep and 1.35m wide was installed horizontally around the room on the east at a level 0.3m below the ground surface. The room on the west has no such “horizontal” insulation. Five-year measurements of air temperatures in both rooms, soil temperatures around the rooms, energy consumption for space heating, and so forth were made in four different situations. An experimental study found that horizontal insulation was effective in reducing the annual temperature fluctuation of indoor air, and in reducing the heating load. These effects, which were also analyzed from the viewpoint of heat balance in the room, were verified by computer calculations based on the two-dimensional finite element method.

Review of passive systems and passive strategies for natural heating and cooling of buildings in Libya

By proper passive design concepts which essentially consist of collection, storage, distribution, and control of thermal energy flow, an energy saving of 2.35% of the world energy output is possible. The basic methods of heating and cooling of buildings are solar radiation, outgoing longwave radiation, water evaporation, and nocturnal radiation cooling. A Trombe-Michel wall consists of a large concrete mass, exposed to sunlight through large, south-facing windows; it is used for heating buildings. Solar absorption cooling and solar dehumidification and evaporative cooling are two approaches that utilize solar energy for the generation of the working fluid and the cooling of dwellings. Outgoing longwave radiation is the most practical way of cooling buildings in desert climates and is effective on roof surfaces, emitting the radiations from the surface of earth to the atmosphere and to outer space. Water evaporation in desert coolers is the usual method of cooling in arid regions. Nocturnal radiation both heats in winter and cools in summer, in suitable climates, and does so with no nonrenewable energy other than a negligible amount required to move the insulation twice a day. The study of 24 different locations in Libya divides the country into regions with distinct passive strategies. The northern region and the Mediterranean coast need passive heating. The buildings in this region should restrict conductive heat flow, prevent infiltration and promote solar heat gains. The southern region, a part of the Sahara desert, needs passive cooling. The buildings in this region need high thermal mass and should promote natural ventilation, restrict solar heat gains and encourage evaporative and radiant cooling. The difficulties encountered in passive solar design are the large exposed area required with suitable orientation for the collection of energy and the large space requirement for the storage of thermal energy. This paper reviews these passive systems and discusses suitable strategies to be adopted for Libya.

A review of passive systems for natural heating and cooling of buildings

In the present era of energy crisis, energy required for heating and cooling of buildings is 6.7% of the total world energy. Utilization of natural heating and cooling systems which essentially consist of collection, storage, distribution, and control of thermal energy flow can save 2.35% of the world energy requirement. The basic methods of heating and cooling of buildings are: solar radiation, out-going longwave radiation, water evaporation, and nocturnal radiation cooling. Trombe-Michel wall consists of large concrete mass, exposed to sunlight through large, south facing windows, is used for heating the buildings. Solar absorption cooling and solar dehumidification and evaporative cooling are two approaches which utilizes solar energy for generation of working fluid and cooling the dwellings. Longwave radiations emitted by the surface of the earth to the atmosphere and outer space is very strong in a desert climate and is effective from a roof surface. Water evaporation by desert coolers is the method of cooling in arid regions. Nocturnal radiation both heats in winter and cools in summer, in suitable climates, and does so with no non-renewable energy other than a negligible amount required to move the insulation twice a day. The difficulty encountered in the utilization of natural energies is the large area exposed with suitable orientation for collection of energy and large space requirement for the storage of thermal energy. This paper reviews these passive systems for natural heating and cooling of buildings.