AC & Air Handler
Easy System Selector Tool
Use this tool to guide you to the best heating and cooling solution for your home.
AC & Air Handler
AC Tonnage (Select One)
Please select an AC tonnage to continue.
How to Determine the Right BTU or Tonnage for Your HVAC System
Use the guide and tools below to find the right system size for your space.
STEP 1: LOCATE YOUR CURRENT SYSTEM'S INFO
You can usually find the BTU listed on your furnace's data sticker, often located inside the cabinet door or on the inner or outer wall of the cabinet. On an air conditioner, the data sticker is typically found on the outer panel of the outdoor condenser unit, often near the electrical disconnect box.
Look for terms like M/N, Prod, Mod No, or Model Number to identify your system. These numbers can also help you find a replacement if needed and the product manual (if you need to look up the BTU/Tonnage).
STEP 2: CALCULATING BTU AND TONNAGE
You can also use the model number to determine BTUs. You'll find an even number within the model number string. Multiply this number by 10,000 to calculate the unit's BTU.
From there, tonnage is typically calculated by dividing BTUs by 12,000 (since 1 ton = 12,000 BTUs).
If you don't have product data available, you can also use our sizing calculator to use square feet to determine your needs.
Furnace Data Sticker
Model Number: DGAT070BDF
BTU: 70,000
AC (Heat Pump) Data Sticker
Model Number: ACIQ-24-HP
BTU: 24,000 TONNAGE: 2.0
Tonnage
Tonnage in air conditioning refers to the unit's cooling capacity, where 1 ton equals the ability to remove 12,000 BTUs of heat per hour.
