Heating Cost Calculator

Heating Cost is evaluated from Home Size, Annual Heating Degree Days and Home Insulation Level. The calculation reports Annual Heat Load, Annual Fuel Used and Estimated Annual Heating Cost.

Results

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About the Heating Cost Calculator

Heating Cost is treated here as a quantitative relation between Home Size, Annual Heating Degree Days, Home Insulation Level and Heating Fuel and Annual Heat Load, Annual Fuel Used, Estimated Annual Heating Cost and Average Monthly Heating Cost.

The calculator uses a multi formula configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.

Formula basis:
Heat load = UA x HDD x 24 BTU/year
Where UA = floor area x 0.5 BTU/hr/ degF/sq ft / insulation multiplier
Fuel cost = heat load / system efficiency / fuel energy content x fuel price

Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.

Formula & How It Works

The calculation applies the following relations exactly as recorded in the metadata:

Heat load = UA x HDD x 24 BTU/year
Where UA = floor area x 0.5 BTU/hr/ degF/sq ft / insulation multiplier
Fuel cost = heat load / system efficiency / fuel energy content x fuel price

Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.

Worked Examples

Example 1: 2,000 sq ft home, Chicago (6,500 HDD), average insulation, natural gas at $1.20/therm

Inputs

home_sqft: 2000 hdd: 6500 insulation: 1.00 fuel_type: gas fuel_rate: 1.2
Annual Heat Load: 156 MMBtu/year. Annual Fuel Used: 1696 therms/year. Estimated Annual Heating Cost: $2,035/year. Average Monthly Heating Cost: $170/month

With Home Size = 2,000, Annual Heating Degree Days = 6,500, Home Insulation Level = 1 and Heating Fuel = gas as the stated inputs, the result is Annual Heat Load = 156 MMBtu/year, Annual Fuel Used = 1696 therms/year and Estimated Annual Heating Cost = $2,035/year. Each value corresponds to the declared output fields.

Example 2: 1,500 sq ft home, Boston (6,500 HDD), below-average insulation, heating oil at $3.50/gal

Inputs

home_sqft: 1500 hdd: 6500 insulation: 0.70 fuel_type: oil fuel_rate: 3.5
Annual Heat Load: 167.1 MMBtu/year. Annual Fuel Used: 1425 gallons/year. Estimated Annual Heating Cost: $4,987/year. Average Monthly Heating Cost: $416/month

With Home Size = 1,500, Annual Heating Degree Days = 6,500, Home Insulation Level = 0.7 and Heating Fuel = oil as the stated inputs, the result is Annual Heat Load = 167.1 MMBtu/year, Annual Fuel Used = 1425 gallons/year and Estimated Annual Heating Cost = $4,987/year. Each value corresponds to the declared output fields.

Example 3: 3,000 sq ft home, Minneapolis (8,000 HDD), good insulation, heat pump at $0.14/kWh (Xcel Energy)

Inputs

home_sqft: 3000 hdd: 8000 insulation: 1.60 fuel_type: heatpump fuel_rate: 0.14
Annual Heat Load: 180 MMBtu/year. Annual Fuel Used: 17586 kWh/year (heat pump). Estimated Annual Heating Cost: $2,462/year. Average Monthly Heating Cost: $205/month

With Home Size = 3,000, Annual Heating Degree Days = 8,000, Home Insulation Level = 1.6 and Heating Fuel = heatpump as the stated inputs, the result is Annual Heat Load = 180 MMBtu/year, Annual Fuel Used = 17586 kWh/year (heat pump) and Estimated Annual Heating Cost = $2,462/year. Each value corresponds to the declared output fields.

Example 4: 2,500 sq ft home, Dallas (2,500 HDD), above-average insulation, propane at $2.50/gal

Inputs

home_sqft: 2500 hdd: 2500 insulation: 1.30 fuel_type: propane fuel_rate: 2.5
Annual Heat Load: 57.7 MMBtu/year. Annual Fuel Used: 701 gallons/year. Estimated Annual Heating Cost: $1,751/year. Average Monthly Heating Cost: $146/month

With Home Size = 2,500, Annual Heating Degree Days = 2,500, Home Insulation Level = 1.3 and Heating Fuel = propane as the stated inputs, the result is Annual Heat Load = 57.7 MMBtu/year, Annual Fuel Used = 701 gallons/year and Estimated Annual Heating Cost = $1,751/year. Each value corresponds to the declared output fields.

Common Use Cases

  • Estimate annual home heating costs by fuel type
  • Compare gas vs. electric heat pump vs. oil heating costs
  • Calculate impact of insulation improvement on heating bill