Thermal comfort (PMV and PPD indices) of a floor return underfloor ventilation system was evaluated through experiments with different supply air temperatures and internal heat loads. Results are shown and analysed.
Thermal comfort obtained with a ceiling cooling system was investigated through experiments with human subjects. Results give their perception of thermal comfort and its relationships with skin temperatures measured at several parts of the body.
The control of thermal environment is complicated in buildings with glass-covered atriums. Numerical simulation can play an important role in the heating, ventilation, air-conditioning (HVAC) design of atriums. Many researches have developed various computational fluid dynamics (CFD) methods to accurately predict the thermal environment in atriums. However, a simple, reliable and fast method to deal with complex building construction is more suitable for building designers and engineers to take as a routine assistant tool of HVAC design.
Traditional residential buildings in Anhui, Southern China, maintain comfortable indoor thermal conditions in the summer without any air-conditioning. To understand this phenomenon, the building thermal environment was simulated to study the physical principles for maintaining natural thermal comfort. Measured data such as outside temperatures, solar radiation intensities, the thermal characteristics of the structure, and the interior gain were used as the boundary conditions.
Efficient energy utilization and indoor air quality (IAQ) inside office premises and other public places have become issues of increasing concern in the Hong Kong Special Administrative Region (HKSAR). The Government of HKSAR has launched a territory wide consultation in 1999 on the proposed Indoor Air Quality Management Programme for offices and public places. This paper briefly introduces the proposed Indoor Air Quality Management Programme and its proposed target objectives.
Thirty female subjects were exposed for 280 minutes to four conditions in balanced order of presentation: to 20 C/40%, 23 C/50%, 26 C/60% RH at10 L/s/p outside air, and to 20 C/40% RH at 3.5 L/s/p. They performed simulated office work throughout each exposure and repeatedly marked a set of visual-analogue scales to indicate their perception of environmental conditions and of the intensity of SBS symptoms at the time. They were repeatedly reminded to adjust their clothing so as to remain in thermal comfort, and succeeded in doing so.
As part of a graduation research, six case studies were carried out to assess the validity of 10 often heard assumed disadvantages of natural ventilation in offices, including poor IAQ and thermal discomfort. The case studies included a methodic comparison of six buildings based on literature, interviews, field measurements and re-analysis of reports by others. Thus the preconditions for natural ventilation of office buildings and the most important design features could be determined in order to meet the performance standards as in use in the Netherlands.
A big airport hangar for planes (177x37x92 m) was studied using CFD in cold season conditions. Without nozzle jets for air supply, severe temperature stratification occurs. With nozzle jet fans (17 m/s - 11000 m3/h), the average temperature in the occhupied zone is increased of 2 C.
This study investigated if low air temperature, which is known to improve the perception of air quality, also can reduce the intensity of some SBS symptoms. In a low-polluting office, human subjects were exposed to air at two temperatures 23 C and 18 C both with and without a pollution source present at the low temperature. To maintain overall thermal neutrality, the low air temperature was partly compensated for by individually controlled radiant heating, and partly by allowing subjects to modify clothing insulation.
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