Graduation date: 1998

The airflow pattern and contaminant distribution under non-isothermal turbulent flow conditions in a swine growing/finishing building were investigated experimentally and numerically. In the test facility, the ventilation system consisted of discontinuous ceiling inlets with recirculation assisted slots. Air speed, dust and ammonia concentration at selected locations in the-building were measured during the winter ventilation season in a cold climate. The corresponding temperature distribution at one cross section within the air space also was measured. Experimentally it was found that both the ventilation rate and the recirculation rate had a limited effect on the dust concentration. The ventilation rate had a significant effect on the ammonia concentration in the air space, while the recirculation rate did not affect the ammonia concentration. The FLUENT computer code was used to simulate the air flow pattern and ammonia concentration in the swine building. The numerical simulation model used was the k-$\varepsilon$ turbulence model which includes a buoyancy term. The predicted airflow pattern indicated that the flow structure in such a ventilated swine barn is a three-dimensional flow. The three-dimensional flow structure and the contaminant concentration and temperature at the human breathing line were highly affected by the combined behavior of ceiling inlet jets and recirculation slot jets. The presence of pigs in the swine building had three effects: the air stream near the pigs was deflected; the air speed above the pigs was increased; and the ammonia concentration in the air space was decreased. Both experimental and numerical results showed that temperature and ammonia concentration were uniformly distributed across most of the air space in a building ventilated with discontinuous ceiling inlets and recirculation slots. Numerical results also indicated that the heat generated by animals affected the airflow pattern. Increasing the heat load at the floor resulted in increased air speed, temperature, contamination level, turbulence kinetic energy, dissipation rate and effective viscosity along the breathing line. The placement of the ceiling inlet and the recirculation duct affected airflow patterns, but had only a slight effect on the distribution of temperature and ammonia concentration along the human breathing line. Increasing the flow rate of cleaned recirculation airflow resulted in lower ammonia contaminant level along the human breathing line. However, higher flow rates of cleaned recirculation air means there will be higher fan operation and air cleaning costs. The optimum ratio of ventilation rate to the cleaned recirculation air rate appeared to be approximately 1:4.

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.

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With environmental concern growing in both affluent and developing countries, roof top ventilators, a form of natural ventilation requiring only wind energy to ensure quality air circulation and comfort is becoming a considered choice of many households and industries. Unfortunately, however, many of these ventilators have evolved through trial and error and the flow physics associated with these ventilators is barely understood. The present experimental project was, therefore, undertaken as part of UNSW- Industry collaboration program funded under an Australian Research Council Grant to explore whether the aerodynamics forces acting on these ventilators during their operation could be obtained. A commercial roof top ventilator supplied by industry was, therefore, tested in an open jet wind tunnel of the University of New South Wales and the results are presented in this thesis. A novel feature of this project is the examination of the suitability of ???the three dimensional wake traverse??? technique to the wake of rotating ventilator. This technique has so far been applied with limited success to the wake of lifting bodies of fixed wing configuration only. In the absence of adequate data in the literature on rotating ventilator, the aerodynamics force components obtained by this technique have been compared against force balance measurements. The results show that the wake traverse technique is capable of determining lift and total drag forces associated with the ventilator flow during its operation from the pressure and velocity information gathered downstream of a ventilator in its wake. Generally, from these data, the technique also allows isolation of the profile and induced components of the drag force. However, from the induced drag value, while it is possible to determine the lift force, it is however, found that a more accurate value of lift force can be evaluated using axial vorticity formulation. The availability of the above technique which does not require measurements on the test specimen itself, will aid in providing a cost efficient investigation of the aerodynamic forces and consequently the performance of a roof top ventilator.

Thesis (Ph. D.)--University of North Texas, May, 2008. / Title from title page display. Includes bibliographical references.

Thesis (Ph.D.)--Drexel University, 2009. / Includes abstract and vita. Includes bibliographical references (leaves 204-212).

Globally, there is growing concern about energy consumption and its diverse effects on the environment. In South Africa, the current status quo is unfavourable in the domain of energy, hence the Department of Energy, Eskom and NERSA have embarked on supporting energy efficiency technologies nationwide as a strategic goal in reducing demand on the national grid. Due to the non conservative consumption of electricity from the grid and the insufficient supply to meet its demand, the importation of crude oil is very certain. In addition, the current and most popular technology for pool water heating in the said country is the resistive element which is inefficient and non-cost-effective. The energy consumption of residential swimming pool water heating is very massive, and tariff structure shows a constant rise. Furthermore, there's a current electricity crisis during the Eskom evening peak. Hence, a reliable, efficient, cost-effective and renewable energy technology such as an air source heat pump is required as a retrofit to the existing resistive element. Furthermore, mathematical modelling is a tool that can be used to mimic the dynamic behaviour of a physical or process system. It is a computational language or mathematical equation used to predict the dynamic behaviour of physical systems [Tangwe et al., 2015]. Various methods such as numerical methods have been considered as the particular types of mathematical modelling which have been employed to predict the performance of swimming pool ASHP water heater. However, they were unreliable and expensive. Consequently, this research focused on the experimental determination of the viability and development of a mathematical model to predict the performance of swimming pool ASHP water heater. The benefit of the development and building of this model was attributed to its low cost and credibility to forecast the performance of swimming pool ASHP water heater. Also, this robust mathematical model can be used by an energy service company and system manufacturer to compute the dynamic coefficient of performance of the swimming pool ASHP water heater. Following the above-mentioned information, the research sought to provide a permanent solution to the Eskom evening peak constraint. This is because energy-efficiency, serves as the bridging block between conventional and renewable energy sources needed by Eskom in a bid to provide a balance energy mix and sustainable energy. The implementation of a swimming pool ASHP water heater guaranteed a conducive environment for the population due to the reduction in environmental pollution.

xvi, 117 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Energy and environmental concerns warrant reconsideration of operable windows as a means of ventilating and cooling office environments. To design for optimal window use and performance, architects must understand human interaction with operable windows and the factors that influence occupant participation in their thermal environment. This thesis examines workers' personal control of operable windows in their office space through the lens of the following attributes: proximity, orientation, and accessibility to operable windows, office floor height, and the operational methods of windows. Three sites in the Minneapolis metro area were examined through site visits, informalinterviews, collection of physical traces, and a questionnaire. Research data reveal that proximity is the greatest determinant of window use. Other attributes have varying degrees of influence on use of windows. Surprisingly, workers valued operable windows significantly more for fresh air than for cooling. / Committee in Charge: Professor John Rowell, Chair; Professor Brook Muller; Professor G.Z. Brown

First, this research has attempted to identify the underlying reasons for high Chinese family cooking energy consumption. Second, this research has tried to identify ways of reducing Chinese kitchen cooking fume pollution. The literature review indicated that, although cooking energy takes one of the largest proportions of residential building energy consumption, previous studies in this area have not been enough. The published knowledge found indicates that urban residential buildings takes 1/4 of the national building energy consumption (excluding heating). This portion has grown continuously since 2001 in terms of energy consumption intensity (kgce/m2). Among household energy (excluding heating), cooking, home appliances and lighting are the three largest energy end users. Although the increase in cooking energy is low, partially attributed to wide adaptation to gas cooking fuel instead of coal fuel in China, it still takes the largest household energy consumption: 31% in 2011. Many research papers report different results based on field measurements of household energy end users, some of which show conflicting results. However, the literature review has confirmed that in China cooking energy consumes the second-largest amount of household energy after space heating. The literature review also pointed out that, although compared with Western counterparts, Chinese residential buildings consume less national energy, cooking takes a large percentage of household energy. A further literature review showed little valuable information underpinning the reasons for high cooking energy use in Chinese households. Some overseas research papers give hints regarding cooking energy and cooking techniques, cookware, and occupant behaviour. However, the difference in food culture traditions has led to a greater difference between Western and Chinese cooking techniques. Compared with Western countries, Chinese hot dishes require a greater number of cooking techniques. In order to find out more details of cooking energy and fume generation in real Chinese home kitchen conditions, the author used a series of research methodologies to measure and test home energy and cooking fume concentration. The results reconfirm that cooking energy is the second-largest home energy end user after space heating, along with other findings. These other findings include: • The four largest energy end users in northern Chinese households are space heating, cooking, hot water and entertainment. • Hot water, lighting and entertainment energy consumption have clear seasonal characteristics i.e., daily consumption is low in summer and high in winter. This is because of the colder weather in winter (demanding more energy to heat water) and longer nights in winter (with a longer indoor entertainment time and a greater requirement for lighting in the evening). • Daily cooking energy consumption in a given family is almost fixed, although the difference between different families is large. This could lead to further study on the underlying reasons for the difference between families. The most important finding in the research is the discovery of the relationship between home cooking energy and family life cycle. A strong relation was observed between these two factors. This was confirmed by the measurement of the test families as well as the survey of 70 random selected families. The relation is, therefore, denoted as the CookEUI (cooking energy use intensity) of the different family life cycles. Following the data analysis and survey, it was also found that the cooking energy for a certain family life cycle was constant, i.e., locked in an FLC stage until the stage changed. Finally, a database was built into the IES energy simulation using figures found in the research. This represents significant progress in home energy study. Before discovering cooking EUI, cooking energy in most pieces of energy simulation software was treated as a process load with a constant figure. A literature review of a large number of research papers concluded that cooking fumes have an adverse impact on people’s health. In China, a typical housewife spends about 4 hours in the kitchen every day, preparing and cooking meals. A comfortable and healthy cooking environment is critical for cooks’ health. It was also found that COF emissions in Western and Chinese kitchens differed largely in mass concentration. Cooking method, cooking oil and cooking temperature all contribute to the difference. Many other researchers have investigated the details of hood systems and their construction features in order to understand their efficiency in removing cooking fumes. However, most of the research has been based on commercial kitchen application. There is very little research on home kitchen hood efficiency. Research also points out that natural ventilation in the kitchen space has a certain amount of influence on the capture efficiency of an exhaust system. For example, opening the door is more efficient than opening a window. In this research, the measurements of kitchen PM2.5 and PM10 were carried out in real home kitchen cooking conditions. The relation between PM2.5 and PM10 emissions and different Chinese cooking methods was measured. It was found that deep frying and stir frying discharged the most PM2.5, while boiling emitted the least. A typical PM2.5 discharging pattern in Chinese cooking was observed. The pattern showed a sharp increase in PM2.5 concentration in the beginning at breath level with a drop afterwards because of the using up of cooking oil or the rising of water steam to a higher level. A small sub-surge was observed after the first selection because the downward flow of cold air brought high-level PM2.5 down to breath level. A very interesting finding observed when using tracer gas to measure kitchen cooking hood efficiency was the large difference between the airflow rate listed on the kitchen fume hood nameplate and the airflow rate measured in real kitchen conditions. On the nameplate of the cooking hood, airflow was rated as 800 m3/h at medium speed, while in the tracer gas testing the flow rate was a maximum of 175 m3/h when all the kitchen windows and the door were open. This finding reinforces the experiment conclusion by the Lawrence Berkeley National Laboratory for the seven representative devices they tested, whereby, according to Chen (2012), the capture efficiency varied from less than 15% to more than 98%. Identifying the airborne moving characteristics of PM2.5 can be used to help redesign ventilation systems for Chinese home kitchens. The traditional way of enhancing cooking fume removal efficiency is to increase the fan discharge pressure head. This leads to increased energy consumption. It also has less effect on removing PM2.5 particles, since, unlike PM10, PM2.5 is affected by airflow rate more significantly than air velocity. The proposed new ventilation system is intended to treat PM2.5 and PM10 separately. PM10 will be removed by the filter in recirculation devices and PM2.5 will be exhausted by a direct venting fan with replacement air. In this way, less energy is used and the system is more efficient at removing kitchen PM2.5.