About HVAC Contractor Services

« Back to Home

Why Knowing Commercial AC Terms Is Important

Posted on

Setting up a commercial air conditioning system is a job that carries with it a slew of challenges. As the customer, it's a good idea to have some familiarity with the terminology used within the industry. If you want a professional to know that you understand what you're talking about, here are 5 concepts to keep in mind.


Most people are familiar with the use of British thermal units, usually stated as BTUs, in the industry to express capacity. One oddity within the trade, however, it to discuss A/C system capacities in terms of tons. 12,000 BTUs of output translates into one ton of capacity, and a 5-ton setup is widely considered the minimum for a commercial-level system.


While you've likely seen the term right on the box of every residential A/C you've ever bought, the idea of the BTU probably remains rather abstract. In order to cool a one square foot area, you'll need about 24 BTUs of output. Adding people changes the equation, as an individual working an 8-hour day should add about 380 BTUs of required capacity.

Kilowatt Hours

Figuring out how much juice will be needed to keep a commercial air conditioning system running is an important long-term consideration. The most common electrical consumption figures cited in the industry will be kilowatt hours (kW/h). The efficiency of systems varies quite a bit, but most modern setups should consume roughly 1.33 kW/h of electricity per ton of ton of capacity. Efficiency numbers tend to improve the larger a system becomes, but this will provide you a starting point for generating an estimate.


In the broadest sense, the average commercial air conditioning unit has two components. The indoor element, commonly called the evaporator, is the one that is cool. The outdoor section, usually called the condenser, runs hot. This process draws heat away from a structure and releases it into the air.

Power Sources

The larger an A/C setup is at a business, the more likely electrical upgrades will be required. It's a good idea to have these concerns in mind before consulting with an HVAC contractor, and you may have to engage in a little back-and-forth between them and an electrical technician to see that your whole system is properly powered. For low-demand setups, you may be able to operate on standard 120v power, but for others, a 230v, or even three-phase system might be necessary.