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How do I find the size in tons of a Bosch heat pump?
Wednesday, April 14, 2021
You can determine the size in tons of your Bosch HVAC system by examining the model number on the data sticker at the side of the condenser (outdoor unit). Look at the first two numbers of the middle cluster of digits of the model number, which will be a two-digit number divisible by 6 or 12; and represents the nominal BTU of the system in thousands. A ton of air conditioning equals 12,000 BTU so, for the model number (BOVA-60HDN1-M18M shown below, 60 divided by 12 equals 5 tons.
Some models may have a slightly different serial number configuration, but you will still be looking for that number divisible by 12 or 6. Here’s a rundown of the range you will encounter: 18 = 1.5 tons, 24 = 2 tons, 30 - 2.5 tons, 36 = 3 tons, 42 = 3.5 tons, 48 = 4 tons, and 60 = 5 tons.
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 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 determine the age of a Bosch HVAC system, see How so I find the age of a Bosch heat pump from the serial number? For the age of another brand or manufacturer, go to our blog post How do I determine the age of my air conditioner?
And to figure out what all the other numbers listed on the condenser data plate mean, go to our blog post How do I understand the air conditioner or heat pump condenser label (data plate)?
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To learn more about heating and air conditioning systems, see these other blog posts:
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