Air Balancing: The Final Step in Every Installation

In an ideal world, every technician would be aware of the importance of two words: air balancing. The concept is well-known (if not always well-implemented) on the commercial side of the business, but a very low percentage of residential homes are balanced. And that's a shame, because having the proper amount of air delivered to each room dramatically affects both customer comfort and a home's energy efficiency.

Many technicians "slap systems in," more concerned with speed than quality. The ductwork doesn’t fit? No big deal, just make it smaller. They don't understand the effect of that change on the system. Ductwork was designed to be a certain size to move a certain amount of air. Changing it affects volume and velocity of the air, both of which affect comfort and efficiency.

There are many training resources available for air balancing, and an array of tools and instruments to help you do the job. But first and foremost, air balancing is a matter of understanding the big picture. That ability is what separates a true service technician from a parts changer.

Understand why it’s important to deliver the proper cubic feet per minute (cfm) that each room is designed to receive. Then look at the rooms themselves. Is there a fireplace in the living room? When that fireplace is operating, it's going to be sucking a lot of conditioned air up the chimney. Is your system providing enough air to keep the homeowners comfortable under those conditions? The same holds true for kitchen exhaust fans and bathroom fans. If a system is designed to accommodate a 50 cfm bathroom fan, understand why it's a bad idea to install one that pulls 100 cfm. More is not always better.

Most technicians know how to install a furnace or air conditioner. Think of air balancing as the final step in a unit’s installation — the step that will ensure that it is operating at peak performance.

Michael Schatzer is an estimator and project foreman with Shapiro & Duncan Mechanical Contractors, Rockville, MD, and a NATE “Top Tech.” He can be reached at 240/427-7791 or [email protected].

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