How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manfuactured and modular homes
How many tons is my air conditioner or heat pump?
Tuesday, July 21, 2020
It’s easy to find the tonnage once you get the hang of it. Hunt for a number that is divisible by 6 or 12 somewhere in the center of the model number on the data plate at the side of condenser (outdoor unit), like 12,18, 24, 30, 36, 42, 48, or 60.
A ton of air conditioning equals 12,000 BTU so, for example a “24” in the middle of the model number indicates that it is a 2-ton system, a “30” means 2-1/2 tons, and the “42” in the middle of the model number at the top of the page means the system is 3-1/2 tons.
Here’s a few more examples:
Trane - 4TWR3030A1000AA - 2-1/2 tons
Carrier - 38BYC030360 - 3 tons
York - YCE48B21SA - 4 tons
Goodman - CPRT36-1 - 3 tons
Trane - TTR060C100A2 - 5 tons
Goodman - GSH130241AC - 2 ton
Your probably noticed that the last model number had two numbers, “30” and “24,” that are both divisible by 6. Several of the others are the same way. Generally, the second number is the right one. Also, the number of tons of cooling capacity indicated is “nominal,” meaning that the actual BTU’s are approximately the number indicated, but may slightly more or less.
If you are unsure whether you have found the right two numbers, you can double-check it by looking for the “RLA” rating on the data plate. RLA is an acronym for Rated Load Amperage, and is what the maximum amperage should be when the condenser is up and running. If you divide the RLA by 6 for older units and 5 or 6 for newer units, you should get a number that approximates (not exactly) the tonnage of the system. Make sure you use RLA and not LRA, Locked Rotor Amperage, which is the surge of amps necessary to overcome inertia and start the system. It averages around five times the RLA.
To get specific instructions and an example for your brand, click on one of the links below:
Affinity Aire-Flo Airquest Amana
American Standard Ameristar Arcoaire
Bard Bryant CAC/BDP Carrier
Comfortmaker Cumberland Daikin Ducane
EcoTemp FHP (Florida Heat Pump) GE
Goodman Grandaire Guardian Heil
International Comfort Inter-City Products
Janitrol Lennox Luxaire Maytag
Miller Mitsubishi Nordyne Nortek
Panasonic Payne Rheem Ruud
Stylecrest Revolv Sears Kenmore
Tempstar Thermal Zone Trane
Unitary Products WeatherKing Xenon York
To determine other key specs of your HVAC system, see one of these other blog posts:
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To learn more about heating and air conditioning systems, see these other blog posts:
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