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What is HVAC Tonnage and Why Does it Matter?

The term HVAC tonnage relates specifically to your HVAC cooling system. A ton in HVAC terms refers not to the weight of your central air conditioner or heat pump but to its cooling capacity.

Understanding HVAC Tonnage

In this article, we will discuss:

  • How HVAC tonnage is calculated
  • The importance of selecting the right HVAC tonnage
  • Working with an HVAC professional to get the right AC sizing

Determining the Correct Tonnage

Determining the correct AC tonnage for your home will depend on several factors. For the most accurate AC load calculation, work with a trained HVAC professional.

Some of the factors to consider include:

  • The region you live in
  • Your cooling needs
  • The size of your home
  • The layout of your home
  • Your home’s ductwork
  • Your home’s insulation and ventilation
  • The current energy efficiency of the home

The following tonnage chart gives you a rough idea of the correct AC tonnage or heat pump cooling ability needed to cool a home based on square footage.

BTU to Tons Notice that one ton corresponds to 12,000 BTUs (British Thermal Units). One BTU refers to the amount of heat that’s needed to raise or lower one pound of water by one degree Fahrenheit. That means it can be used to rate energy transfer for furnaces, heat pumps, and other heating and cooling equipment.

Home size (sq. ft.)Unit Size (tons)Unit Size (BTUs)
1000 sq. ft.2-ton AC unit/2-ton heat pump24,000 BTUs
1500 sq. ft.3-ton AC unit/3-ton heat pump36,000 BTUs
2000 sq. ft.4-ton AC unit/4-ton heat pump48,000 BTUs
2500 sq. ft.5-ton AC unit/5-ton heat pump60,000 BTUs

You can find your system’s current tonnage by looking in your owner’s manual, or at the information plate on the outdoor unit, usually located on the side or back of the unit. Look for the model number, and then within the model for an even number between 18 and 60. That is the BTU rating for the unit. Divide that number by 12, and you’ll have your AC tonnage.  

The chart above does not include 1.5-ton, 2.5-ton, and 3.5-ton units, but those are available as well in certain product lines. If you’re shopping for a new HVAC system, you might also find our system recommendation tool helpful.

The Impact of Correct AC Tonnage on Energy Efficiency

When it comes to AC tonnage and your home, you want the Goldilocks system – not too big, and not too small. If the system is too small, it won’t cool your home as it should. It will have to run for longer periods to get your home to the desired temperature. That means higher energy bills.

If the system is oversized, it may be too powerful and cool your home too quickly, resulting in the thermostat shutting the unit off before it completes a full cycle. This is known as short cycling. This can lead to premature wear and tear, and higher energy bills. It can also mean the system doesn’t properly dehumidify your home, making you feel cold and clammy.

Work with an HVAC Company You Can Trust

For the most accurate AC sizing or HVAC system sizing, consult with a reputable HVAC contractor. They will use the Manual J Residential Load Calculation to make precise recommendations. 

If you’re getting a new air conditioner or new HVAC system, proper sizing is crucial to optimal energy efficiency. When you get a new air conditioner or heat pump, you will want to consider replacing your furnace at the same time so that you have a matched system. This system can offer the best energy efficiency, and some warranties require it.

Consult with a Trane Comfort Specialist

The best way to ensure your new air conditioner has the correct tonnage and is sized right for your home is to contact your local Trane Comfort Specialist. They have the experience and expertise to help you get the air conditioner or new HVAC system that’s right for you and your home.

Contact a local dealer

Dealers can answer questions, help you find the right products for your home, and repair your system.

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Connect with our Customer Care team about your products, warranties, and dealer concerns.

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