With all the talk about indoor air quality (IAQ), it is surprising that we can overlook probably the most important component of a healthy indoor environment. The American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) recommend a continuous supply of 15 cubic feet per minute per person of outside air to maintain healthy office environments. Low toxicity paints and earth-friendly furnishings do not eliminate the need for fresh air ventilation.
The Typical Diagnosis
We have conducted hundreds of evaluations of commercial buildings where the occupants report respiratory illness, headaches, and other symptoms of sick building syndrome. Many times the occupants are convinced they have a mold problem.
Here is the typical diagnosis: INSUFFICIENT VENTILATION.
Reasons for the Chronic Lack of Ventilation Air
1. Maintenance staff receive little or no training on ventilation
Facility managers and maintenance personnel receive little or no training on the importance of ventilation to the health and productivity of the occupants. If the maintenance staff can keep the building cool in the summer and warm in the winter, they believe their job is done.
2. Outside air gets shut off during weather extremes
It is a little known fact that heating and air conditioning engineers do not design systems to maintain indoor set points during the very coldest or very hottest days of the year. This would result in oversized and inefficient systems during the majority of the year. However, when these very cold or very hot days inevitably arrive, the savvy maintenance technician knows that he can shut off the outside air supply and squeeze more performance out of the system. This is a short-term solution with long-term negative effects. If the maintenance tech does not restore the outside air supply when the weather extremes have passed, occupants may begin to notice a decrease in comfort, productivity, and general health.
3. Contractors substitute equipment for fresh air
Heating and air conditioning contractors do not always have sufficient education on the importance of ventilation. When confronted with health complaints, they may promote ultra violet lights, high efficiency filtration, and even equipment replacement. These things are not effective substitutes for fresh air ventilation.
4. Some buildings have no provision for outside air at all
Many commercial buildings have heating and air conditioning systems that have no provision at all for outside air. Random leaks and penetrations in the building envelope provide accidental ventilation. Is there any wonder that occupants in these buildings are not as productive as they could be?
5. Supply and return air are out of balance
The supply and return air systems may not be properly balanced. This condition creates pockets of stagnant air. Occupants in these areas suffer due to an invisible but very real problem. Most unfairly, managers and coworkers may see them as “complainers.”
So What Is the Take Away?
A large number of indoor air quality problems result from poor ventilation and not a specific airborne contaminant. Unfortunately, insufficient ventilation is the rule and not the exception. When occupants report symptoms of poor indoor air quality, go directly to the building’s ventilation system (if there is one) and see what you find.
Contact: Barry Westbrook
Phone: 615-373-2498
Email: bwestbrook@docair.com
