How to Calculate Heat Pump Savings
What is Heat Pump Savings?
The Heat Pump vs Furnace Savings Calculator compares the annual heating and cooling costs of an electric heat pump versus a traditional gas furnace and central air conditioner system, accounting for efficiency ratings and local energy prices.
Formula
Annual Savings = Gas Furnace Heating Cost + AC Cooling Cost - Heat Pump Combined Heating & Cooling Cost
- HDD
- Heating Degree Days (degree-days/year) — Annual measure of heating demand based on outdoor temperature
- HSPF
- Heating Seasonal Performance Factor (BTU/Wh) — Heat pump heating efficiency rating; higher is better (8-13 typical)
- AFUE
- Annual Fuel Utilization Efficiency (%) — Gas furnace efficiency rating; 80-98% for modern furnaces
- COP
- Coefficient of Performance (dimensionless) — Ratio of heat output to electricity input; heat pumps achieve COP 2-4
Step-by-Step Guide
- 1Enter your home square footage and local climate zone heating/cooling degree days
- 2Input local electricity rate ($/kWh) and natural gas rate ($/therm)
- 3Compare equipment efficiencies: furnace AFUE vs heat pump COP/HSPF
- 4The calculator computes annual operating costs for each system and shows net savings
Worked Examples
Input
2,000 sq ft, moderate climate (4,000 HDD), $0.14/kWh, $1.20/therm, 96% AFUE furnace vs 10 HSPF heat pump
Result
Furnace + AC: $2,180/yr; Heat Pump: $1,540/yr; Annual savings: $640
Input
2,000 sq ft, cold climate (7,000 HDD), $0.14/kWh, $0.80/therm
Result
Furnace + AC: $2,450/yr; Heat Pump: $2,280/yr; Savings only $170/yr — gas is cheap here
Common Mistakes to Avoid
- ✕Not considering that heat pump efficiency drops significantly below 20F — cold climates may need a dual-fuel backup
- ✕Comparing a cheap heat pump SEER 15 to a high-efficiency furnace 96% AFUE without matching quality tiers
- ✕Ignoring the IRA heat pump tax credit of up to $2,000 which dramatically improves payback
Frequently Asked Questions
Are heat pumps cheaper to run than gas furnaces?
In moderate climates with electricity under $0.15/kWh, heat pumps typically save 20-40% on annual heating costs. In very cold climates with cheap gas, savings may be minimal without a cold-climate rated heat pump.
Do heat pumps work in cold climates?
Modern cold-climate heat pumps (ccASHP) work efficiently down to -15F. Models from Mitsubishi, Daikin, and Bosch maintain 70-80% capacity at 5F, making them viable in most US climates.
Ready to calculate? Try the free Heat Pump Savings Calculator
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