Electric resistance and pool heat pumps heat the same water—but not with the same grid kWh. This guide walks through the heat pump vs electric pool heater cost calculator: same thermal load, COP-adjusted heating kWh, and side-by-side monthly cost bars.
Benefits
- Apples-to-apples comparison: identical heat demand, different COP for each heater type.
- Shows monthly heating cost for resistance vs. heat pump at your electricity rate.
- Annual HP vs. electric savings line pairs with pump cost and optional cover savings.
How it works
- Enter pump kW and run hours—the tool models heat demand from that operating profile.
- Set heat pump COP (typically 4–6); resistance stays at COP 1 automatically.
- Read monthly heating cost bars and annual savings switching from electric to heat pump.
FAQ
How much cheaper is a pool heat pump vs electric resistance?
Heating grid kWh = heat demand ÷ COP. At COP 5, a heat pump uses about one-fifth the grid kWh of resistance for the same thermal load—roughly 80% less heating electricity. Dollar savings = (resistance kWh − heat pump kWh) × $/kWh. Example: 30 kWh/day thermal load → 30 kWh resistance vs 6 kWh at COP 5 → 24 kWh saved × $0.14 ≈ $3.36/day on heating alone.
What COP should I use for a pool heat pump?
Many air-source pool heat pumps run COP 4–6 in mild weather; colder ambient air lowers COP. Start with COP 5 in the calculator, then try 4 for conservative winter estimates or 6 for mild-climate shoulder seasons. Resistance is always COP 1.
Does pump electricity count in the heat pump vs electric comparison?
Pump kWh is the same either way—the comparison isolates heating cost. The visual bars show monthly heating dollars for resistance vs. heat pump on the modeled thermal load. Total daily cost adds pump kWh plus whichever heating method you actually use.
Technical specifications
- Resistance heating kWh = heat_demand_kWh ÷ 1.
- Heat pump heating kWh = heat_demand_kWh ÷ COP (4–6 typical).
- Monthly heating $ = daily_heating_kWh × 30 × $/kWh per method.
- Related: pool-heating-cost-calculator, heat-pump-vs-resistance, pool-energy-thermal-cover.
Same heat load, different meter kWh
Both heater types must replace the same evaporation and conduction losses. Resistance converts electricity directly to heat at COP 1. A heat pump moves ambient energy into the water, so one grid kWh can deliver several kWh of heat. The calculator holds thermal load constant and only changes COP—so the cost gap is technology, not wishful smaller pools.
Read the monthly bars, not just COP labels
COP 5 sounds abstract until you see resistance at $180/month and heat pump at $36/month on the same load. The comparison visual translates COP into dollars at your $/kWh rate. That is the number that justifies equipment quotes—not the brochure efficiency line alone.
When resistance still wins on paper
Very short swim seasons, rarely heated water, or gas backup can shrink electric heating hours. If you only heat a few weeks a year, upfront heat pump cost may dominate operating savings—run annual dollars here with realistic pump hours and cover use before deciding.