What Commercial HVAC Unit Size do You Need?

What Commercial HVAC Unit Size do You Need?
January 7, 2016 nobleair

When you need to purchase a new commercial heating and air unit for your business, you’re probably most concerned with the acquisition and installation costs. Some business owners make the mistake of buying a system based mostly on price. While you certainly want to save money where you can, it’s very important to think long term. You must consider not only the cost of the unit, but also, how efficient it is, so you save money month after month. This can be done, in large part, by knowing what size commercial HVAC you need.

What Commercial HVAC Unit Size do You Need?

Air conditioners, as you might know, are measured in tons. Of course, this isn’t the weight measurement associated with very large objects; it isn’t 2,000 pounds. A ton in the world of HVAC is the measurable ability to heat or cool. To give you a better understanding, 1 ton will yield 12,000 BTU’s, or British Thermal Units in one hour. What this means is 1 BTU will heat or cool one pound of water by one degree Fahrenheit.

If an HVAC system is undersized, there will be more hours per year when the plant is running fully loaded, and the system will not be able to hold indoor design conditions even on a design day, let alone any hotter days; that is, temperatures in these air-conditioned spaces will rise. If an HVAC system is over-sized, it will never run fully loaded ― a log of chiller loading will reveal that utilized capacity will almost always be less than 80 or 90 percent of installed capacity. —Construction Innovation

The average household HVAC unit ranges from 1 to 5 tons, however, units over 5 tons are generally considered commercial. So, a 6 ton commercial HVAC system will output 72,000 BTU’s in an hour. Why all of this is so important is it gives you a general idea of just how big a commercial heating and cooling unit you need to keep your business comfortable. If the unit is too small, it will use more energy to try and reach the programmed temperature (which might not happen, depending on the conditions). This means it will continue to run, wasting energy, and, increasing your utility costs. Should a system be over-sized, it will use more power to run but never achieve its maximum efficiency. This is why it is imperative to select the right sized unit.

To know approximately what size commercial HVAC system you need for your business, you can use this simple method: the square footage, multiplied by 25, divided by 12,000) minus 0.5) equals the required tons for your commercial space.

Don’t make the mistake of believing whatever size unit(s) are currently installed will be the correct replacement size. Because commercial HVAC units are more energy efficient than years ago, the size of the unit(s) needed could be different. To know for sure what size commercial heating and air system you need for your business, contact an experienced, licensed technician. You should also inquire about the ductwork and other components to get the most efficient configuration.