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What Is an A/C Ton Mean?

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If you are familiar with HVAC systems, then you have probably come across the term A/C Ton at some point. The HVAC industry tends to have technical terms that may have a completely different meaning from layman language.

For example, you may be thinking about installing an HVAC system in your home. While doing your own research, you come across the term AC tonnage. What is it, and how does it affect the type of HVAC system you buy? Keep reading to find out.

What Is an Air Conditioner Ton?

An air conditioner ton is a term used to rate air conditioning units. At first glance, one might think that ton refers to the weight of the AC system. However, an AC ton is described as the amount of heat an air conditioner can remove from a building within an hour.

The standard measurement of heat in the HVAC field is a British Thermal Unit (BTU). One ton can remove 12,000 BTUs of heat from a building in an hour. This means that a four-ton AC unit can remove approximately 48,000 BTUs of heat from a building and so forth.

Why Tonnage Is Important When Buying an AC Unit

You may already know that mini splits are more efficient than central air, but you also need to understand tonnage. That's because the tonnage of an AC unit will determine whether the air conditioner will work efficiently in your home. If you buy an oversized AC unit for your home, be prepared to deal with the following consequences. 

Short Cycling

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An oversized air conditioner tonnage will experience short cycling, thereby consuming more energy. Short cycling refers to when the AC unit turns on, cools your home quickly, then turns itself off, only for it to turn back on soon after and repeat the process. It takes a lot of energy to turn the system on. The right-sized AC unit will run continuously for a longer period of time and then shut off for a period of time, thus consuming less energy. If you have been getting extremely high energy bills since you installed a new AC unit, short cycling might be the cause.

What if you buy an undersized AC unit? Will it consume less energy?

No. An AC unit with the wrong tonnage will struggle to cool the building, causing it to run more and use up more energy. If you want to be sure you are getting the right AC unit for your home, we recommend having a heat load performed before you install the new AC system. Our experts at Comfort Up can perform a heat load test to help you pick the right AC.

High Humidity Levels

An oversized AC unit will cause your home or building to have extremely high humidity levels. This is because a short cycling AC unit will not be able to remove moisture effectively from the building. Normally, when moisture builds up on the evaporator coil, it flows over the coil and drains into the drain pan.

However, if the air conditioner tonnage is too high, the moisture building up on the evaporator coil will not drain into the drain pan but will instead evaporate back into the air within the building. This inefficiency is caused by the short running time of the AC unit. Too much humidity leads to an uncomfortable, clammy, and cold atmosphere in your home.

Noisy AC System

If you buy an AC with the wrong air conditioner ton for your building, the fans will operate at an unusually high speed. This will cause air to flow faster throughout the air ducts and return registers, producing more noise due to the performance stress. The loud noise may interfere with your sleeping patterns and may make your home uncomfortable. If you would rather not deal with any noise at all, we recommend buying a ductless AC system.

How to Pick the Right Air Conditioner Tonnage


The best way to pick the perfect AC tonnage for your home is to calculate the size of your home space. We recommend multiplying the length and width of each room in your home to get the area. Once you do that, multiply the area of each roof by 25 to find the BTU capacity required for the room. If the area of a room is between 250 and 300 square feet, it will require about 7000 BTUs. Do this calculation for each room to find the total BTUs required by an AC unit in your home.

At Comfort Up, we are ready to help you with the calculations. Give us a call today, and our experts will calculate the exact square footage of your home and determine the number of BTUs an AC would require to work efficiently. As you ponder between central air vs split system ACs, make certain that you put the tonnage into consideration.


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