When you hear or read about commercial air conditioning systems, you’ll often come across the word tons used to refer to equipment. For example, light commercial air conditioning service, which is what our company provides, refers to equipment that is 25 tons and under. You might think this refers to how much the equipment weighs, but that’s not the case.
Tons or tonnage instead refers to the amount of cooling power an air conditioning unit delivers. We’d like to help you better understand this terminology—it will make it easier for you to know what work is being done for your commercial facility when you have new equipment installed. Our technicians are always willing to provide you with any information you may need.
What AC Tonnage Means
A ton is the cooling capacity of an air conditioning system. One cooling ton is equal to 12,000 BTUs (British Thermal Units) of heat removed per hour. Since most commercial systems have more than 5 ton cooling capacity, you can see why using this measurement is convenient: a 15 ton commercial AC removes 180,000 BTUs per hour. It’s much easier to compress that down to a convenient “15 tons.”
But why is this measurement called tons in the first place? The reason is that 12,000 BTUs is the amount of heat needed to melt one ton of ice at 32°F over 24 hours. This is an old measurement that was set as the industry standard in 1903.
Matching AC Tonnage to a Building
Now that you know what tons means for an air conditioning system (probably more than you ever wanted to know), the next question is: “How many tons of cooling do I need for my facility?” That’s an important question, and it’s one that you need commercial HVAC professionals to answer.
Tonnage must be carefully matched to a facility. An AC unit cannot be undersized, or else it will not provide sufficient cooling. But it can’t be oversized either because this leads to a malfunction called short-cycling, where the AC turns on and off rapidly rather than completing a full cooling cycle.
Finding the right tonnage of air conditioning system for a building requires professionals to size the AC with a load calculation. A load calculation factors in various criteria about the building, such as the equipment inside it, the number of windows and their sun exposure, the heat given off by lights, and the standard number of people indoors, and comes up with a tonnage amount for an AC to provide. Modular rooftop air conditioning units allow for easy adding of units to meet the tonnage amount.
All of this also applies to packaged heat pump systems, which work as both heating and cooling systems—it’s a general term that can be applied to all refrigerant systems.
Call Us for Light Commercial AC Installation
We offer complete service for light commercial air conditioning in Everett, WA. We’ll make sure you have the right new units for your facility, whether it’s a new business or you are replacing existing AC units. We are certified and union-trained in light commercial.
Evergreen State Heat & AC serves King County and Snohomish County. Call Now—24/7 On-Call Dispatching.