| Does more fresh air equal better quality air in commercial buildings? The American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) has changed the requirements (ASHRAE Standard 62) several times since its inception in 1989. The changes were necessitated by many factors, not the least of which was the tremendous utility cost increase on those buildings which implemented the 20 cubic feet per minute standard of fresh air for each tenant. This air must be preheated or precooled, dependant upon the outside temperature. Most older commercial office buildings do not have the capability of inducing that amount of fresh air into the HVAC system. Several major leases with high-density tenant occupancy have been decided based upon the ability of the building to provide adequate outside air. The theory is sound, but what is the reality? Is that volume of outside air in any major city really clean or fresh? The question of outside pollutants and odors that must be removed from air in a major city must also be considered. Additionally, allowing excessive moist air into a building can exacerbate mold formation. How much of the odor, pollutants, and moisture can you filter out and what is the extra expense? There are several products on the market that are excellent, but very expensive. In an attempt to avoid the "sick building syndrome" and all of the legal issues that can result, are we really curing the problem?
Facilities Management or Energy Management Systems with the proper outside and inside air sensors do provide an excellent method of monitoring, alarming, and controlling conditioned and unconditioned air, but some ancillary equipment may be required.
Now we must endure the issue of terrorism and the possibility of someone adding chemical or biological agents into the air intake of buildings. If the fresh air intake is on ground level, then extra security must be provided. Thankfully the majority of fresh air intake is on the roof level of most properties.
Many changes have taken place since the inception of ASHRAE Standard 62, and if it has not affected you as of yet – it will!
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