During the past three years, BRE has conducted winter and summer occupant surveys on satisfaction with environmental conditions in 23 buildings. These were a mixture of naturally ventilated and air conditioned buildings. The results presented in this paper are based on a secondary analysis of 5136 completed questionnaires. The aim of the analysis was to determine the effect of ventilation type and season on occupant satisfaction with key environmental parameters: thermal sensation, thermal comfort, humidity, air movement, stuffiness, air quality, lighting and noise.
This paper presents general guidance on designing for thermal comfort in combined chilled ceiling/displacement ventilation environments. Thermal comfort measurements involving 184 human subjects were carried out in a laboratory- based test room, constructed to resemble a normal office and equipped with a combined chilled ceiling and wallmounted displacement ventilation system.
Unsolicited complaints from 23,500 occupants in 690 commercial buildings were examined with regard to absolute and relative frequency of complaints, temperatures at which thermal sensation complaints (too hot or too cold) occurred, and response times and actions. The analysis shows that thermal sensation complaints are the single most common complaint of any type and that they are the overwhelming majority of environmental complaints.
In March of 1996, a new Elementary School was occupied which is the first in the United States to utilize the concept of displacement ventilation as the primary means of providing both good indoor air quality and thermal comfort. In addition, the integrated "sustainable" design concepts of the facility also address other important factors including: siting, programming, lighting, acoustics, energy efficiency, classroom computer usage, and access for planned HV AC preventive maintenance.