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Sounding Board: Beware of AHU's in Parking Garages

Dec. 15, 2020
Air-handling units that service office lobbies require extra monitoring for leaks, one helpful reader notes.

Dear Editor:

In the November 2020 issue of HPAC Engineering, it was mentioned that an air-handling unit serving the lobby unit was placed in the second floor of the parking garage in the article, "Post-COVID Office Building Has Arrived."

As a building scientist specializing in the achievement of healthy indoor environments, I wanted to note that in my experience of dealing with degraded IEQ in buildings, the culprit has often been the placement of an AHU near a source of air contaminants. This situation arises simply because AHUs leak, if not initially, they will over time. Sometimes it is not just the AHU. In fact, mechanical rooms are almost always at a negative pressure with respect to their surrounding and, therefore, at risk of capturing air contaminants from their surroundings and transporting these air contaminants to the occupied spaces.

Just a word of warning as something to be aware of. So I offer the suggestion that a special effort be made to identify and seal any leaks into this AHU located in the parking garage.    

David W. Bearg, P.E.

Life Energy Associates, Concord MA

The author is a member of HPAC Engineering's Editorial Advisory Board. Contact him at [email protected].