2595 (RP-198) -- Thermal Comfort during Cyclical Temperature Fluctuations

In order to determine the effect of cyclical temperature fluctuations on thermal comfort, 804 subjects were exposed to various basal temperatures (64, 67, 73, 79 and 85FET) which fluctuated at different amplitudes, A, (2, 4, 6, 8 and 10F) at rates of 2, 4, 6, and 8F/h. From their responses, equations were developed which enabled the prediction of the thermal sensation votes at the high and low points of the cycle both when the temperatures were increasing and decreasing from the basal condition. The results showed for humans engaged in near-sedentary activities while wearing light clothing, if the temperature conditions for comfort are met, the thermal environment will be acceptable if (a) the rate of change does not exceed 6F/h (3.3C/h) and (b) the peak-to-peak amplitude is equal or less than 6F or 3F (3.3C or 1.6C). The conditions will be unacceptable both in and out of the comfort envelope at temperatures which (a) fluctuate at rates greater than 6F/h (3.3C/h) or (b) have peak-to-peak amplitudes which are greater than 6F or 3F (3.3C or 1.6C). The equations were also used to predict the thermal sensations under ramp conditions. The most comfortable ascending ramp condition is when the basal temperature is increasing from between 70F and 74F at the rate of 1F/h. The most comfortable decreasing ramp conditions is when the basal temperature is falling from between 78F and 84F at the rate of 1F/h.

Citation: ASHRAE Transactions, Volume 86, Part 2, Denver, Colorado



Product Code(s): D-DV-2595