Environmental Comparison of Air Conditioned Buildings and Non-Air Conditioned Buildings

This multi-disciplinary project presents the results of a major research initiative to determine the environmental difference between air-conditioned and non-air-conditioned buildings and their relationship to building-related illnesses.

The environmental conditions in five buildings were monitored in comprehensive detail by BSRIA.

An average of over 200 occupants in each building were subjected to a doctor-administered questionnaire undertaken by the North West Lung Centre.

The statistical analysis of the results was undertaken by medical statiticians at the University of Manchester.

The study has identified that air-conditioned buildings, when well designed and maintained, can be associated with very low levels of symptoms attributable to the Building Sickness Syndrome.

In other buildings, the factors responsible for inducing the symptoms vary, and the interactions between environmental parameters and symptoms will differ in different buildings.

Important and repeatable findings have included the importance of particulates for all symptoms, the relationship between symptoms and low internal humidity and the more complex relationships with thermal comfort. Noise has proved to have an unusual pattern of association, with low-frequency noise being directly and higher-frequency noise inversely related to symptoms.

Reduced levels of ions may be associated with symptoms as do increased levels of carbon dioxide, although the independent nature of these associations is unclear.