Subjective responses to atmospheric humidity.

Abstract Three humidities, 20, 50, and 75% relative humidity (RH), at 2 temperatures, 23 and 28°C were set up in the environmental chamber at the Electricity Council Research Centre, Capenhurst. Subjects in the age range 16–19 years, each experienced one condition for 6 hours. Warmth votes were recorded at hourly intervals and a 16 item questionnaire was completed at the end of the morning and afternoon. Humidity did not affect the subjects' warmth votes at 23°C, but at 28°C the warmth vote increased by 0.8 interval on the Bedford 7 point scale as the humidity increased from 20 to 75% RH; this is equivalent to an increase in temperature of 2.5°C. At 23°C the subjects distinguished between the humidities on the evaluative scales. Both the low and high humidities were found more oppressive and uncomfortable than 50% RH. At 28°C the low humidity (20% RH) condition was preferred; higher humidities were found more oppressive, more uncomfortable and more moist.