Many instances have been uncovered where architects and mechanical engineering firms oversized the air handler. For example, where the conditions called for a 50 ton unit, 75 tons or higher was installed. Bigger must be better was the supposed reasoning.
Unfortunately, this mistake costs the building owners over 20 million dollars in the end and nationwide infamy. Why?
Air handlers not only must provide adequate cooling, but also reduce the amount of moisture or humidity of the inside air. When the units were started up, cooling was almost immediate. However, the cooling capacity of the units was so large that the unit was able to come on only for a few minutes before it shut off again.
As a result, little moisture was removed and the humidity levels remained high. In Florida, where high humidity is a fact of everyday life, moisture removal is vital. Normally in air conditioners where the air moisture condenses upon cooling coils (similar to the condensation on the outside of a glass of water you may drink in a restaurant), and moisture in the air is removed.
What is known by all indoor air quality professionals is that humidity levels over 60% are conducive to fungal (mold) growth. In this Florida case above, moisture was not removed ever from the air. A building occupant, after the new building was condemned and occupants evacuated, stated “It was either hot and damp or cold and damp in the building. But it was always damp.”
Owners were confronted with bulldozing down the marble enclosed building and re-‐building it from scratch, or trying to repair the existing building.
There are other areas however where bigger is better. Handling mold issues in the HVAC condensate collection pan is one of them. My next blog will address this important factor.
Please do not hesitate to leave your comments or testimonials below.
Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.