How To Determine Ac Tonnage From Model Number Lennox. Use the serial number 5498l9988 for an example. Divide the number by 12 (which represents 12,000 btu/hr, or one ton of cooling capacity) to get your ac unit’s tonnage.
How do you tell the tonnage of a model number? A ton of air conditioning equals 12,000 btu, and 48 divided by 12 equals 4, so the data plate below indicates the system is 4 tons. To estimate your ac tonnage needs, multiply the number of square feet you’re cooling times 25.
Accessing the lennox model number may requires remove and set aside your furnace’s front door.
Model is identified by a ”model number“ which is stamped on the unit nameplate or rating plate. Divide the number by 12 (which represents 12,000 btu/hr, or one ton of cooling capacity) to get your ac unit's tonnage. Tonnage is a measure of btu’s in 12,000 btu increments. The possibilities on residential units range from 18 to 60.