Heating Capacity Ratings: What You Need to Know

Not all stoves are created equal, and we’re not just talking about looks. When buying a stove or insert, it’s important to choose one with a heating capacity that’s appropriate for your home. A hearth expert at your local Forge & Flame dealer can help you, and will base his or her recommendations on several factors.

Climate Zone
The climate where you live will affect the heating capacity of your stove or insert. Use this map to determine what climate zone you live in, and then follow the steps below.

Climate zone map of the United States
  • Product brochures for each Forge & Flame stove and insert (available by clicking on Downloads from the product page) include “heating capacity” ratings. The ratings represent the square footage the stove or insert is capable of heating in Zone 4. 
  • If you don’t live in Zone 4, a simple calculation will provide the heating capacity for the zone where you live. Multiply the “heating capacity” in the brochure with the number that corresponds to your climate zone below.
    • Zone 1 - .50
    • Zone 2 - .65
    • Zone 3 - .90
    Example: 
    Brochure rating is 1,300-2,900 sq. ft. (Zone 4)
    1,300-2,900 x .50 (for Zone 1) = 650-1,450 sq. ft.
    1,300-2,900 x .65 (for Zone 2) = 845-1,885 sq. ft.
    1,300-2,900 x .90 (for Zone 3) = 1,770-2,610 sq. ft.

Other Factors
The heating capacity, or the square footage your stove will heat, is determined primarily by the BTUs of the stove. In addition, various structural factors have an effect on your stove’s ability to heat and maintain the temperature of the space. Factors like the insulation and weatherproofing, ceiling height and the openness of the floor plan should be taken into consideration.

House cross section illustration
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