Free Air Conditioning that Costs You a Fortune

Free Air Conditioning that Costs You a Fortune

The air conditioning that cools your home likely runs only 3 or 4 months a year. But commercial buildings have much more glass, equipment, lighting and people per square foot, and their cooling systems can run 9 or 10 months a year. That harder work means higher electric and repair bills. But wait; if the inside needs cooling in March (pretty common) but outside it’s 65 degrees, why not use that “free” cool air outside to keep the inside comfortable?

You’d think that’s a great idea, and it should be. But if not done right, it can cost you a fortune, and here’s why…

The method chosen to capture the “free” cool air is an accessory called an economizer. It’s a motorized damper controlled by a temperature sensor, opening during mild weather to bring in cool outside air, and the closing when outdoor temperatures rise to keep that hot outside air out. At least, that’s the theory. In practice, economizers have been cheaply built and poorly installed. The temperature sensors used are crude and inaccurate, and quickly fall out of calibration. Mediocre service technicians disable the dampers, or the linkages fail and the dampers no longer open or close.

What does this mean for you? It means you pay more for cooling your building than you have to. If the damper fails when it’s closed, it means you never get the benefit of the free outdoor air, costing you money in running air conditioning when there’s a much cheaper alternative. But things get worse when the damper fails when it’s open. Now, at summer’s height, your equipment is sucking in 100 degree air inside your building. The hotter it gets, the harder your equipment works and the more scorching outdoor air it pulls in. What a costly problem to have!

Do you have it? Well, economizers have been mandated by California law for about 30 years, so the odds are your current equipment includes them. When were yours last checked for proper operation? When was the temperature sensor last calibrated?

At last, some well-built economizers are coming to market, with accurate digital sensors and robust mechanical parts. These can save you plenty in energy costs, on moderate days as well as real scorchers. Call us at Air-Tro to schedule a time when I can come out or send a service tech to check the economizers on your existing systems. You’ll be glad you did.