An experimental technique for thermal comfort comparison in a transient pull down

Various types of spaces are controlled for maintaining a desired comfort-condition level. Examples include buildings, automobiles, airplanes, and trains. The steady-state or longer-duration HVAC control is well established. However, situations are encountered where a rapid march towards a thermal space comfort level is required such as in the parked automobiles or in buildings where thermal mass is utilized for conserving energy. Many times design changes are proposed to improve the transient pull down in one zone but that could significantly affect the transient pull down in another zone. Further, in addition to the temperature, other parameters such as air velocity, mean radiant temperature, humidity need to be considered for assessing space comfort level. In our work we have developed an experimental technique for the multi-zone or comparative assessment of thermal comfort in a transient pull-down situations. First, the fan and system curves were developed for the competing designs. The predicted mean vote (PMV) methodology was employed for determining perceived comfort level. PMV is an ideal technique since it accounts for all of the above-mentioned parameters that are needed to assess space comfort level. Using an indoor climate analyzer, the transient PMV response at various locations was obtained. Conclusions are drawn to illustrate how this technique can be utilized for the simultaneous assessment of thermal comfort level in multiple zones, especially when transient pull downs are encountered.