Personal Air-Conditioning
Majority of air-conditioned offices rely on total volume air distribution (TVAD) to attain a fairly homogenised mix of fresh and recirculated air, supplied at temperature and velocity that would satisfy most occupants.
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Personal Air-Conditioning
Majority of air-conditioned offices rely on total volume air distribution (TVAD) to attain a fairly homogenised mix of fresh and recirculated air, supplied at a temperature and velocity that would satisfy most occupants. The aim of TVAD is to achieve uniform temperature and velocity in the occupied zone and environment designed for an ‘‘average occupant.’’ This approach is too simplified and does not have the potential to satisfy a majority of room occupants because large differences exist between people with regard to the preferred environment. (Melikov 2004)
Based on survey responses, Brill (1984) concluded that thermal comfort ‘complaints’ were correlated to body size with smaller occupants, typically women, more inclined to complain about temperature fluctuations, especially it being too cool. It was concluded that ‘purely environmental solutions to thermal comfort are probably unattainable, given that body type tends to alter responses so strongly.’ (Federspiel et al. 1998, p. 174) While few have such control [over temperature of their workspace] (only 17 %), those who do are exceedingly more satisfied with their thermal environments. People who have adequate control over temperature experience fewer problems with their office being too cool or too warm, less temperature fluctuation, and more comfort. (Brill 1984, p. 174)
The lowest PPD achievable is 5 % under experimental conditions and 20 % in field studies. Thermal comfort in the future should therefore strive to attain 0 % PPD by offering personal control over the air-conditioning temperature. However, the perfect temperature is a delicate balancing act. Wyon (1989, p. 89) says, ‘For sedentary activities such as office work or driving, it is my experience that a discrepancy of only 5 W/m2 in either direction from thermoneutrality gives rise to a definite feeling of whole-body discomfort after 15–20 min.’ This chapter looks at how personal air-conditioning can be implemented in a way that does not involve large-scale installation or intervention.
T. Law, The Future of Thermal Comfort in an Energy-Constrained World, Springer Theses, DOI: 10.1007/978-3-319-00149-4_9, Springer International Publishing Switzerland 2013
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Personal Air-Conditioning
9.1 Personal Environmental Modules, Task-Ambient Conditioning and Personal Ventilation Occupants have become increasingly aware that there cannot be a universal optimum set of conditions for thermal comfort. Consequently, there has been a push for greater personal control over one’s immediate thermal environment. This has led to the development of small, local cooling systems that supplant or supplement air-conditioning systems like the one illustrated in Fig. 9.1. Personal environmental modules (PEMs) for example, feature a pair of desktop nozzles directed at a user’s upper body and a radiant heat panel for the legs to create a microclimate that can be controlled to a user’s specific requirement (see Fig. 9.2). This system, implemented in the Bank of America, and researche
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