The main objectives of this thesis are to determine if the addition of an energy wheel in an HVAC system can improve the indoor air relative humidity (RH), and perceived air quality (PAQ), as well as reduce energy consumption. An energy wheel is an air-to-air energy exchanger that transfers heat and moisture between the outdoor air entering and the exhaust air leaving a building. This thesis uses the TRNSYS computer package to model two buildings (an office and a school) in four different cities (Saskatoon, Saskatchewan; Vancouver, British Columbia; Tampa, Florida and Phoenix, Arizona).<p>The results with and without an energy wheel are compared to see if the energy wheel has a significant impact on the RH and PAQ in the buildings. The energy wheel reduces peak RH levels in Tampa, (up to 15% RH), which is a humid climate, but has a smaller effect on the indoor RH in Saskatoon (up to 4% RH) and Phoenix (up to 11% RH), which are dry climates. The energy wheel also reduces the number of people that are dissatisfied with the PAQ within the space by up to 17% in Tampa. <p>The addition of the energy wheel to the HVAC system creates a reduction in the total energy consumed by the HVAC system in Saskatoon, Phoenix and Tampa (2% in each city). There is a significant reduction in the size of the heating equipment in Saskatoon (26%) and in the size of the cooling equipment in Phoenix (18%) and Tampa (17%). A cost analysis shows that the HVAC system including an energy wheel has the least life-cycle costs in these three cities, with savings of up to 6%. In Vancouver, the energy wheel has a negligible impact on the indoor RH, PAQ and energy consumption.

The main objectives of this thesis are to determine if the addition of an energy wheel in an HVAC system can improve the indoor air relative humidity (RH), and perceived air quality (PAQ), as well as reduce energy consumption. An energy wheel is an air-to-air energy exchanger that transfers heat and moisture between the outdoor air entering and the exhaust air leaving a building. This thesis uses the TRNSYS computer package to model two buildings (an office and a school) in four different cities (Saskatoon, Saskatchewan; Vancouver, British Columbia; Tampa, Florida and Phoenix, Arizona).<p>The results with and without an energy wheel are compared to see if the energy wheel has a significant impact on the RH and PAQ in the buildings. The energy wheel reduces peak RH levels in Tampa, (up to 15% RH), which is a humid climate, but has a smaller effect on the indoor RH in Saskatoon (up to 4% RH) and Phoenix (up to 11% RH), which are dry climates. The energy wheel also reduces the number of people that are dissatisfied with the PAQ within the space by up to 17% in Tampa. <p>The addition of the energy wheel to the HVAC system creates a reduction in the total energy consumed by the HVAC system in Saskatoon, Phoenix and Tampa (2% in each city). There is a significant reduction in the size of the heating equipment in Saskatoon (26%) and in the size of the cooling equipment in Phoenix (18%) and Tampa (17%). A cost analysis shows that the HVAC system including an energy wheel has the least life-cycle costs in these three cities, with savings of up to 6%. In Vancouver, the energy wheel has a negligible impact on the indoor RH, PAQ and energy consumption.

The aim of this study was to evaluate the effects of environmental design parameters on thermal comfort conditions in the METU Faculty of Architecture Building located in Ankara. The building had some problems in terms of indoor climatic conditions, both in winter and in summer. It was evident that some design parameters caused this undesirable situation. The study therefore focused on understanding and evaluating the effects of design-dependent elements such as thermal mass, the size and orientation of windows, shading and vegetation on thermal comfort conditions in the case study building. While conducting this study, data loggers were used to record temperature and humidity data in predetermined rooms. Data was collected during certain periods in July, August, and September 2006. The data collected was analyzed statistically and hypotheses were tested using ANOVA. This study showed that the effect of thermal mass was almost the same for the rooms investigated owing to the fact that the entire building had been constructed with concrete curtain walls. In terms of thermal performance the number and orientation of the exterior walls, orientation and size of windows, room heights and also sun shading with surrounding vegetation were most effective design parameters for the rooms investigated

The aim of the present research is to identify human subjective response (health and comfort) to the micro-thermal environment established by integration of individually controlled localized chilled beam and chilled ceiling (LCBCC) system and to compare its performance with the performance of mixing ventilation combined with chilled ceiling (CCMV).Experiments were carried out in mock-up of an office (4.1 m × 4.0 m × 3.1 m, L× W× H) with one person under two summer temperature conditions (26 °C and 28 °C). To mimic direct solar radiation in the room, five radiative panels on the wall together with electrical sheets on the half of the floor were used. The test room was set-up with two desks, as two workstations, and one laptop on each table. The main workstation (WS1) was located close to the simulated window. The second work station (WS2) was placed in the opposite side of the room. The room was equipped with two types of ventilating and cooling systems.  The first system consisted of a localized active chilled beam (LCB) unit together with chilled ceiling (CC) panels. The LCB was installed above the WS1 to create micro-environment around the occupant sitting at the desk. The supply flow rate from the LCB could be adjusted by the occupant within the range of 10 L/s to 13 L/s by means of a desk-mounted knob. The integration of mixing ventilation (MV) system and chilled ceiling panels was the second ventilating and cooling strategy. Twenty- four subjects (12 female and 12 male) were exposed to different indoor environment established by two cooling systems. Each experiment session lasted 120 min and consisted of 30 min acclimatization period and 90 min exposure period. The performance of the systems was identified and compared by physical measurements of the generated environment and the response of the human subjects. The study showed that perceived air quality (PAQ), overall thermal sensation (OTS) acceptability and local thermal sensation (LTS) acceptability clearly improved inside the micro-environment by using LCBCC system. Moreover, at the main workstation, OTS and LTS votes were close to “neutral” thermal sensation (ASHRAE seven point scale) when LCBCC system was used. However, OTS and LTS votes increased to the “slightly warm” side of the scale by applying CCMV system which implied the better cooling performance of the LCBCC system. Acceptability of work environment apparently increased under the room condition generated by LCBCC system. In agreement with human subjective study, the results from physical measurements and thermal manikin study showed that uniform thermal condition was generated all over the room. Air and operative temperature distribution was almost uniform with no difference higher than 1 °C between the measured locations in the room. Thus, both LCBCC and CCMV systems performed equally well outside of the micro-environment region. The use of the chilled ceiling had impact on the airflow interaction in the room and changed the airflow pattern. It can be concluded that the combination of convective and radiative systems can be considered as an efficient strategy to generate acceptable thermal condition in rooms.

The urban landscape-heat-health relationship was explored using a model of human thermal comfort (as energy budget) modified to incorporate varying urban landscape. Census Tract-level energy budget was modelled in Toronto during four extreme heat events. Energy budgets (~+80 W m-2) and heat-related ambulance calls (~+10%) increased during heat events and were positively correlated, albeit with some event-to-event fluctuation in relationship strength. Heat-related calls were negatively correlated to canopy cover. “Cooling” design strategies applied to two high-energy budget Census Tracts nearly neutralized (~–25 W m-2) thermal comfort and increased canopy cover (500–600%), resulting in an estimated 40–50% reduction in heat-related ambulance calls. These findings advance current understanding of the urban landscape-heat-health relationship and suggest straightforward design strategies to positively influence urban heat-health. This new high-throughput, Census Tract-level thermal comfort modelling methodology incorporates the complexities of the urban landscape has relevance to landscape architecture, urban design, and public health.

Thermal comfort receives little priority in the planning and design of bicycle pathways. Design tools are required to illustrate the importance of the relationship between climate and bicycling activity to improve the bicycling experience and extend the bicycling season in a cold climate. Microclimatic and bicycle pathway design principles were integrated with a COMFA model to simulate the thermal comfort of users bicycling on a proposed pathway in Ottawa, Canada. Modelling results predicted bicyclists could be thermally comfortable travelling at a steady-state speed of 16.0-19.2 km/h, but preferred to be cooler when travelling at higher speeds and warmer in colder months when standing at rest. Design implications recognized the compatibility of microclimatic and bicycle pathway design principles and demonstrated how a bioclimatic approach to designing bicycle infrastructure can encourage user thermal comfort, mitigate weather discomforts, accentuate seasonal climate conditions, and address a more inclusive combination of bicycle user design criteria.

A well-functioning, energy-efficient ventilation system is of vital importance to offices, not only to provide the kind of comfortable, healthy indoor environment necessary for the well-being and productive work performance of occupants, but also to reduce energy use in buildings and the associated impact of CO2 emissions on the environment. To achieve these goals impinging jet ventilation has been developed as an innovative ventilation concept. In an impinging jet ventilation system, a high momentum of air jet is discharged downwards, strikes the floor and spreads over it, thus distributing the fresh air along the floor in the form of a very thin shear layer. This system retains advantages of mixing and stratification from conventional air distribution methods, while capable of overcoming their shortcomings. The aim of this thesis is to reach a thorough understanding of impinging jet ventilation for providing a good thermal environment for an office, by using Computational Fluid Dynamics (CFD) supported by detailed measurements. The full-field measurements were carried out in two test rooms located in a large enclosure giving relatively stable climate conditions. This study has been divided into three parts where the first focuses on validation of numerical investigations against measurements, the second addresses impacts of a number of design parameters on the impinging jet flow field and thermal comfort level, and the third compares ventilation performance of the impinging jet supply device with other air supply devices intended for mixing, wall confluent jets and displacement ventilation, under specific room conditions. In the first part, velocity and temperature distributions of the impinging jet flow field predicted by different turbulence models are compared with detailed measurements. Results from the non-isothermal validation studies show that the accuracy of the simulation results is to a great extent dependent on the complexity of the turbulence models, due to complicated flow phenomena related to jet impingement, such as recirculation, curvature and instability. The v2-f turbulence model shows the best performance with measurements, which is slightly better than the SST k-ω model but much better than the RNG k-ε model. The difference is assumed to be essentially related to the magnitude of turbulent kinetic energy predicted in the vicinity of the stagnation region. Results from the isothermal study show that both the SST k-ω and RNG k-ε models predict similar wall jet behaviours of the impinging jet flow. In the second part, three sets of parametric studies were carried out by using validated CFD models. The first parametric study shows that the geometry of the air supply system has the most significant impact on the flow field. The rectangular air supply device, especially the one with larger aspect ratio, provides a longer penetration distance to the room, which is suitable for industrial ventilation. The second study reveals that the interaction effect of cooling ceiling, heat sources and impinging jet ventilation results in complex flow phenomena but with a notable feature of air circulation, which consequently decreases thermal stratification in the room and increases draught discomfort at the foot level. The third study demonstrates the advantage of using response surface methodology to study simultaneous effects on changes in four parameters, i.e. shape of air supply device, jet discharge height, supply airflow rate and supply air temperature. Analysis of the flow field reveals that at a low discharge height, the shape of air supply device has a major impact on the flow pattern in the vicinity of the supply device. Correlations between the studied parameters and local thermal discomfort indices were derived. Supply airflow rates and temperatures are shown to be the most important parameter for draught and stratification discomfort, respectively. In the third part, the impinging jet supply device was shown to provide a better overall performance than other air supply devices used for mixing, wall confluent jets and displacement ventilation, with respect to thermal comfort, heat removal effectiveness, air exchange efficiency and energy-saving potential related to fan power.

The aim of this study was to provide information about the effects of construction materials on thermal comfort in residential buildings using Ecotect 5.0. Three residential buildings, each of different construction in the province of Yozgat, Turkey were used as study material to this end. At the end of this study, the effects of materials on thermal comfort have been explained by graphical and statistical analysis. Pertinent literature reports that the thermal responses of occupants depend to some extent on the outdoor climate in naturally ventilated buildings with operable windows. Furthermore, an adaptation occurs in these buildings regarding the occupants&amp / #8217 / previous thermal experiences, the availability of control, and shifts in expectations. The study therefore focused on collecting data on both indoor and outdoor air temperature and humidity to show the comfort level in such buildings. By collecting data on 3 houses constructed of different materials the author aimed to show the effects of materials on thermal comfort. The analyses were further extended with computer simulations, which enabled restriction of the parameters on construction materials. The study has shown that in naturally ventilated residential buildings, construction materials affect both thermal comfort and thermal performance of the buildings. Buildings with traditional construction material showed a better performance in achieving the preferred thermal comfort while decreasing energy costs.

Scandinavian countries have always been the first in investigation and development of new ventilation systems. In the last years, engineers from Finland and Sweden are studying a new ventilation system known “Confluent jet ventilation system” which is trying to improve displacement and mixing results. The aim of this thesis master is to study the behaviour of three different ventilation systems, mixing ventilation, displacement ventilation and confluent jet ventilation, in an office room by mean of three analysis, temperature gradient analysis, tracer gas analysis and thermal comfort analysis, and to compare them to know if the new one, confluent jet, increases the performance of mixing or displacement ventilation system. In case of confluent jet ventilation system, there were two different cases: one with the supply air device at 2.2m high, and the other with it at 1.7m high to compare which one was the correct position and gets the best results. For each studied system 3 different cases were analyzed, having the same parameters each one of them for the three ventilation systems.The measurements were taken in an office room located in the laboratory of the University of Gävle, Högskolan I Gävle, in collaboration with the Finnish company specialized in ventilation systems, Stravent. For temperature gradient analysis, ten sensors took temperatures from the low level, 0.1m high, to the top level of the room, 2.4m, during all the time that the other measurements were being taken. For tracer gas analysis, a data logger took measurements of the contaminant concentration, N2O, from when the contaminant was thrown into the room until it disappeared following a Decay curve. Lastly, in thermal comfort analysis 4 transducers took measurements each 12 minutes of air temperature, operative temperature, air velocity and air humidity are measured in 6 different points inside the office room and at 3 different heights, 0.1m, 1.1m and 1.7m. After analyzing the results of temperature gradient, tracer gas and thermal comfort the best results were obtained by confluent jet system with the supply air device at 2.2m in case of temperature gradient, since the difference of temperatures between the low and the top level were the minimum and contaminants and indoor air were not in a homogeneous mixing. In case of tracer gas, the results about air change efficiency were not the expected because they showed a well-mixed situation for every system and it should not have been like that. It was caused for the influence of a cooling system situated in the ceiling of the room and the temperature difference between inside and outside the room that affected more than expected. Finally, in thermal comfort analysis, the best results were obtained by confluent jet ventilation, therefore in case of the supply air device at 2.2m and in case of it at 1.7m. To sum up, taking account the results achieved, the confluent jet ventilation got the best results and showed that it is a new ventilation system that must be taken in consideration in the following buildings. Between supply air device at 2.2m and 1.7m the results were very similar, but a bit better in case of the highest height.

Due to the current practices of street design in countries with hot and humid climates that prioritise air-conditioned cars as the favoured mode of transport, the physical and spatial characteristics of the street space have failed to retain much or any user-friendliness for walking or for sustaining street life. Moreover, particularly in Saudi Arabia, the increasingly sedentary lifestyle is leading to significant health problems and prevalence of lifestyle diseases. However, there has been limited research conducted on the use of urban streets under hot and humid conditions, and even less is known about the impact of certain sociocultural aspects in, for example, Muslim countries, on the design of streets for walking. Such a situation poses challenges to the urban space researcher and designer interested in gaining a better understanding of how walking can be restored into the street space. This thesis contributes to the advancement of knowledge in this area by integrating three influential factors connected to walking in a single study; an approach which has not been elaborated previously. This thesis aimed to broaden the understanding of pedestrians’ requirements, attitudes and preferences in order to identify ways in which the neglected street space can be reclaimed for walking under hot-humid climatic conditions and to inform decision-making into improved street design. The scope of this research centred on combining an understanding of pedestrians’ thermal comfort in a hot and humid urban environment, that of the city of Dammam in Saudi Arabia, where the problem is particularly acute, coupled with exploration into the socio-cultural aspects through which behaviour such as undertaking increased physical activity is governed. The research postulated an interactive relationship between the existing conditions of the street space and these two factors. Owing to the multifaceted nature of the factors affecting an individual’s choice to walk, there are few accepted theoretical frameworks, hence studying the cause-and-effect relationship between street design and walking is challenging. Following the literature review and analysis of existing street characteristics; the strategy of mixed-method data collection combining participant observation with interviews and a questionnaire was conducted. The findings revealed the dual impact of key street characteristics on pedestrians’ reluctance to walk on streets and this led to two levels of simultaneous interventions being suggested: physical and spatial. The analytical process (1) identified the upper thermal comfort limit for pedestrians by application of the Physiological Equivalent Temperature index, ‘PET’, through use of the RayMan Software; (2) revealed that physical proximity to other people while on the street is the most sensitive socio-cultural issue in the outdoor spaces of Saudi, particularly between the opposite sexes, and that the existing pavements are generally too narrow to accommodate the preferred personal distance; (3) identified appropriate design interventions at the microscale of the street space to introduce improved shading and create air movement to reduce the impact of solar radiation and humidity and thus to contribute towards encouraging more use of streets for walking; and (4) marking the pavement to indicate distance walked along with high quality streetscape elements was shown to attract pedestrians effectively. Such findings have significant implications for restoring the place of walking on streets in hot and humid cities and the research concludes by emphasising: (1) it is the design of the street space in climatically responsive and socio-culturally compatible ways, rather than the configuration of the urban form that is most associated with increasing physical activity; (2) there is a crucial need to redistribute the street space away from cars and towards pedestrians by widening the existing pavements both for satisfying the average personal comfort distance between pedestrians and for incorporating appropriate streetscape elements.