We've all heard a lot about IAQ problems and how they have sometimes led to expensive and disruptive building shutdowns. Preventing such problems is almost always cheaper than handling them in a crisis, but trying to justify the cost involved (before an incident happens) may be difficult. Increasing OA ventilation rates may mean higher energy bills and possibly the need for expanded HVAC plant capacity. Quantifying the benefit may now be a bit easier, however, as a result of some new informational resources.
Published in December 2000 in the Indoor Air Journal (Vol. 10 Issue 4), "Risk of Sick Leave Associated with Outdoor Air Supply Rate, Humidification, and Occupant Complaints" (by Donald K. Milton, P. Mark Glencross, and Michael D. Walters), is a summary of a study performed over several years on a commercial multibuilding facility in the Northeast. Careful measurements were taken of airflow, humidity, contaminants, etc., and corrections made for a variety of factors (including age, gender, seniority, shift, ethnicity, crowding, and type of work). The bottom line: A $1.00 spent on additional OA yields (on average) about $3.00 in greater productivity due to reduced sick leave.