The objectives of the study were to examine and quantify the relationship between vegetation and the thermal performance of residences in a hot arid environment. Also explored were structural and human influences on residential energy consumption. A primary goal was to determine how much energy savings could be realized through strategic planting of vegetation. This study sought to validate previous simulation and modeling studies that documented annual savings of 2-11% on residential cooling loads. Also examined was whether shrubs and grass could provide a benefit similar to that of trees, assessing the importance of evapotranspiration versus shading. An empirical study was conducted using 105 existing homes in the metropolitan area of Tucson, Arizona. Data included construction type, amenities, living habits of occupants, and energy consumption for heating and cooling over a two-year period. These data were analyzed with a combination of bivariate and multivariate analyses to examine direct correlations between specific variables and energy consumption and the relative importance of each variable. These analyses were unable to document any measurable savings in summer cooling loads as a result of vegetation adjacent to the house, and the presence of trees actually increased the winter heating load by 2%. While trees provide important shading benefits, and can reduce the direct solar gain through the windows of a house, analysis demonstrated that structural and human factors were the most important aspects in residential energy consumption. The size of the house is of primary importance. Houses with evaporative cooling consumed significantly less energy than those with air conditioning. Thermostat settings and habits regarding thermostat operation were the most critical human factors. Occupants who adjusted their thermostats a few degrees cooler in winter and warmer in summer realized measurable savings. Occupants who turned their heating and cooling equipment off when they were not home used significantly less energy for heating and cooling. These factors far outweighed any impact from vegetation on annual energy consumption. While trees should not be considered as a primary means of reducing annual energy consumption, properly placed vegetation can provide aesthetic benefits and increase the thermal comfort of the occupants.

Thesis (M.Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: p. 199-203. / by James E. Rosen. / M.Arch.

Predicted cooling system performance plays an important role in choices among alternative system selections and designs. When system performance is expressed in proper indicators such as "overall system energy consumption" or "overall system efficiency", it can provide the decision makers with a quantitative measure of the extent to which a cooling system satisfies the system design requirements and objectives. Predictions of cooling system energy consumption and efficiency imply assumptions about component performance. Quantitative appraisal of the uncertainty (lack of knowledge) in these assumptions can be used by design practitioners to select and design systems, by energy contractors to guarantee future system energy cost savings, and codes and standards officials to set proper goals to conserve energy. Our lack of knowledge has different sources, notably unknown tolerances in equipment nameplate data, and unpredictable load profiles. Both cause systems to under-perform current predictions, and as a result decrease the accuracy of the outcomes of energy simulations that commonly are used to verify system performance during the design and construction stages. There can be many other causes of unpredictable system behavior, for example due to bad workmanship in the installation, occurrence of faults in the operation of certain system parts, deterioration over time and other. These uncertainties are typically much harder to quantify and their propagation into the calculated energy consumption is much harder to accomplish. In this thesis, these categories of failures are not considered, i.e. the treatment is limited to component tolerances and load variability. In this research the effects of equipment nameplate tolerances and cooling load profile variability on the overall energy consumption and efficiency of commonly used commercial cooling systems are quantified. The main target of this thesis is to present a methodology for calculating the chances that a specific cooling system could deviate from a certain efficiency level by a certain margin, and use these results to guide practitioners and energy performance contractors to select, and guarantee system performances more realistically. By doing that, the plan is to establish a systematic approach of developing expressions of risk, in commercial cooling system consumption and efficiency calculations, and thus to advocate the use of expressions of risk as design targets. This thesis makes a contribution to improving our fundamental understanding of performance risk in selecting and sizing certain HVAC design concepts.

Thesis (M.U.D.)--University of Hong Kong, 1997. / Includes bibliographical references (leaves 107-109).

No description available.

No description available.

One of the greatest problems encountered in greenhouses and buildings with large glazing is control of the internal atmosphere. The inherent characteristic of these buildings to act as solar collectors is to be used effectively for collecting and storing the excess solar energy. A new type of glazed roof, a Solar Climate Control roof system, was designed as a means to cool the interior environment of the greenhouses during the daytime and to heat during the nighttime or on overcast days. / A heat exchanger-storage system, using water as a thermal mass is included in the design of the Solar Climate Control system. A film of water flows on the inner surface of the roof and absorbs the direct solar heat radiation, acting then as a cooling agent. The energy absorbed may be reused for nighttime heating. / An efficient water dispersion pipe for the Solar Climate Control system was developed. The use of a soap solution rather than water alone for the Solar Climate Control water film system permitted a significant reduction in pumping rate and improved uniformity of the film. / A computer simulation model was run to determine the energy loads for both a conventional (double glazed roof) greenhouse and one equipped with the Solar Climate Control system. The Solar Climate Control system shows low operating cost and very good efficiency in heat removal.

Cites, and the buildings of which they are comprised, consume a large proportion of the total energy produced within developed countries such as Australia. Much of this energy, particularly in Australia, is derived from fossil fuels and its consumption results in the emission of greenhouse gases that contribute to an enhanced greenhouse effect causing global warming. The need to reduce the energy consumed by residential and commercial buildings is now widely recognised. This has been acknowledged by state and federal governments within Australia and has resulted in strategies intended to increase the efficiency of building construction and operation. The focus of this research has been the place where most Australians live - suburban residential buildings.Residential buildings consume energy in their operation, for space heating and cooling, water heating, refrigeration, cooking, lighting, appliance, and equipment use. However, energy, known as embodied energy, is also expended in the production of basic building materials, the manufacture of building components, the construction of buildings and their maintenance. Described as life cycle energy, the operational energy and the embodied energy accumulating throughout the lifetime of buildings, account for the total energy attributable to them. Previous studies have indicated that the embodied energy of buildings may be a significant component of their lifetime energy. Therefore, a focus solely on their operational energy efficiency may not necessarily result in lifetime energy reductions.The aim of this research, therefore, was to identify and rank the critical factors influencing the lifetime energy of typical low and medium density suburban residential buildings within temperate regions of Australia. To achieve this, several buildings, representative of the dwelling types currently constructed in the suburbs of Melbourne, were selected for study. Factors influencing operational energy and embodied energy were identified. Thermal simulations were conducted for all dwellings to determine their space heating and cooling requirements as each of the factors was varied from base case values. Residential non space heating and cooling energy was determined from Australian statistics. The embodied energy of the dwellings was calculated using methods adapted from the work of other researchers. As for space conditioning energy simulations, the embodied energy was determined for the base case and then for versions in which factors previously identified were varied. Finally, the life cycle energy requirements of the dwellings were determined for a number of low, base case and high energy scenarios. Statistical analyses of operational energy, embodied energy and life cycle energy results were used to determine and then rank the critical factors influencing each. It has been demonstrated that both user behaviour and building design and construction factors critically influence the life cycle energy requirements of the selected residential dwellings in Melbourne, Australia. As an indicator of the importance of building lifetime, factors found to be critical at one stage of the life cycle of a dwelling have been shown to become less critical at another stage. The results also demonstrate that the life cycle energy requirements of dwellings can be reduced significantly through the synergistic operation of a number of the factors identified.

Thesis (Ph.D.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Dr. Yogendra Joshi; Committee Member: Dr. Ruchi Choudhary; Committee Member: Dr. Srinivas Garimella

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Dr. Sheldon Jeter; Committee Member: Dr. Ruchi Choudhary; Committee Member: Dr. Srinivas Garimella.