Heat Pump COP Calculator

Heat Pump COP is evaluated from Outdoor Temperature, Heat Pump Type and Natural Gas Rate. The calculation reports Heat Pump COP at This Temperature, Heat Pump Cost per MMBtu and Gas Furnace Cost per MMBtu.

Results

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About the Heat Pump COP Calculator

Heat Pump COP is treated here as a quantitative relation between Outdoor Temperature, Heat Pump Type, Natural Gas Rate and Electricity Rate and Heat Pump COP at This Temperature, Heat Pump Cost per MMBtu, Gas Furnace Cost per MMBtu and Cost Comparison.

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:
HP cost/MMBtu = electricity rate x 293.1 kWh/MMBtu / COP
Gas cost/MMBtu = gas rate / 10 BTU/therm / furnace AFUE x 100

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:

HP cost/MMBtu = electricity rate x 293.1 kWh/MMBtu / COP
Gas cost/MMBtu = gas rate / 10 BTU/therm / furnace AFUE x 100

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: 35°F outdoor temp, cold climate heat pump, gas $1.20/therm, electricity $0.16/kWh, 80% AFUE furnace

Inputs

outdoor_temp: 35 heat_type: cold gas_rate: 1.2 elec_rate: 0.16 furnace_eff: 0.80
Heat Pump COP at This Temperature: 2.73. Heat Pump Cost per MMBtu: $17.21/MMBtu. Gas Furnace Cost per MMBtu: $15/MMBtu. Cost Comparison: Gas furnace is cheaper by $2.21/MMBtu at this temperature

With Outdoor Temperature = 35, Heat Pump Type = cold, Natural Gas Rate = 1.2 and Electricity Rate = 0.16 as the stated inputs, the result is Heat Pump COP at This Temperature = 2.73, Heat Pump Cost per MMBtu = $17.21/MMBtu and Gas Furnace Cost per MMBtu = $15/MMBtu. Each value corresponds to the declared output fields.

Example 2: 47°F outdoor temp, standard heat pump, gas $1.50/therm, electricity $0.18/kWh, 92% AFUE furnace

Inputs

outdoor_temp: 47 heat_type: standard gas_rate: 1.5 elec_rate: 0.18 furnace_eff: 0.92
Heat Pump COP at This Temperature: 2.52. Heat Pump Cost per MMBtu: $20.98/MMBtu. Gas Furnace Cost per MMBtu: $16.3/MMBtu. Cost Comparison: Gas furnace is cheaper by $4.67/MMBtu at this temperature

With Outdoor Temperature = 47, Heat Pump Type = standard, Natural Gas Rate = 1.5 and Electricity Rate = 0.18 as the stated inputs, the result is Heat Pump COP at This Temperature = 2.52, Heat Pump Cost per MMBtu = $20.98/MMBtu and Gas Furnace Cost per MMBtu = $16.3/MMBtu. Each value corresponds to the declared output fields.

Example 3: 0°F outdoor temp, cold climate heat pump vs. old 60% AFUE furnace, gas $0.90/therm, electricity $0.12/kWh

Inputs

outdoor_temp: 0 heat_type: cold gas_rate: 0.9 elec_rate: 0.12 furnace_eff: 0.60
Heat Pump COP at This Temperature: 2.73. Heat Pump Cost per MMBtu: $12.91/MMBtu. Gas Furnace Cost per MMBtu: $15/MMBtu. Cost Comparison: Heat pump is cheaper by $2.09/MMBtu at this temperature

With Outdoor Temperature = 0, Heat Pump Type = cold, Natural Gas Rate = 0.9 and Electricity Rate = 0.12 as the stated inputs, the result is Heat Pump COP at This Temperature = 2.73, Heat Pump Cost per MMBtu = $12.91/MMBtu and Gas Furnace Cost per MMBtu = $15/MMBtu. Each value corresponds to the declared output fields.

Example 4: Geothermal heat pump, gas $1.80/therm, electricity $0.20/kWh, 96% AFUE furnace comparison

Inputs

outdoor_temp: 20 heat_type: geothermal gas_rate: 1.8 elec_rate: 0.2 furnace_eff: 0.96
Heat Pump COP at This Temperature: 3.5. Heat Pump Cost per MMBtu: $16.75/MMBtu. Gas Furnace Cost per MMBtu: $18.75/MMBtu. Cost Comparison: Heat pump is cheaper by $2.00/MMBtu at this temperature

With Outdoor Temperature = 20, Heat Pump Type = geothermal, Natural Gas Rate = 1.8 and Electricity Rate = 0.2 as the stated inputs, the result is Heat Pump COP at This Temperature = 3.5, Heat Pump Cost per MMBtu = $16.75/MMBtu and Gas Furnace Cost per MMBtu = $18.75/MMBtu. Each value corresponds to the declared output fields.

Common Use Cases

  • Calculate heat pump COP at different outdoor temperatures
  • Compare heat pump vs gas furnace operating costs
  • Determine break-even electricity rate for heat pump vs gas