Economizer system cost effectiveness: Accounting for the influence of ventilation rate on sick leave

TitleEconomizer system cost effectiveness: Accounting for the influence of ventilation rate on sick leave
Publication TypeConference Proceedings
Year of Publication2003
AuthorsWilliam J Fisk, Olli Seppänen, David Faulkner, Yu Joe Huang
Conference NameProceedings of the Healthy Buildings 2003 Conference, December 7-11, 2003
Volume3
Pagination361-367
Date Published12/2003
PublisherHealthy Buildings 2003, Inc., Singapore
Conference LocationSingapore
Abstract

This study estimated the health, energy, and economic benefits of an economizer ventilation control system that increases outside air supply during mild weather to save energy. A model of the influence of ventilation rate on airborne transmission of respiratory illnesses was used to extend the limited data relating ventilation rate with illness and sick leave. An energy simulation model calculated ventilation rates and energy use versus time for an office building in Washington, D.C. with fixed minimum outdoor air supply rates, with and without an economiser. Sick leave rates were estimated with the disease transmission model. In the modelled 72-person office building, our analyses indicate that the economizer reduces energy costs by approximately $2000 and, in addition, reduces sick leave. The financial benefit of the decrease in sick leave is estimated to be between $6,000 and $16,000. This modelling suggests that economizers are much more cost effective than currently recognized.