Heat Pump Guide: How They Work & When They're Worth It
Heat pumps deliver 2–4× more heat per unit of electricity than a conventional heater. Here's how they work, what types exist, and how to decide if one is right for your home and climate.
🌡️ Key Takeaways
- ✓Heat pumps move heat, not create it — achieving 200–400% efficiency
- ✓Modern cold-climate models work efficiently down to -15°C (5°F)
- ✓One system provides both heating in winter and cooling in summer
- ✓US federal tax credit covers 30% of cost (up to $2,000) through 2032
- ✓Payback vs. gas heat: 4–12 years depending on gas/electric price ratio
How a Heat Pump Works
A heat pump works like a refrigerator in reverse. Your fridge extracts heat from inside and dumps it outside (feel the warm coils at the back). A heat pump extracts heat from cold outdoor air (or the ground) and delivers it inside your home.
This sounds counterintuitive — extracting heat from cold air — but even air at -10°C contains substantial thermal energy. The refrigerant cycle compresses and expands a fluid to move this heat across a temperature gradient.
What is COP?
The Coefficient of Performance (COP) is the ratio of heat output to electricity input. A COP of 3 means 3 kWh of heat is delivered for every 1 kWh of electricity consumed — effectively 300% efficiency.
| Heating system | Efficiency | Heat per unit of energy |
|---|---|---|
| Electric resistance heater | 100% (COP 1.0) | 1 unit |
| Gas furnace (modern) | 80–98% | 0.80–0.98 units |
| Air-source heat pump (mild weather) | COP 3–5 | 3–5 units |
| Air-source heat pump (cold weather, -10°C) | COP 1.5–2.5 | 1.5–2.5 units |
| Ground-source heat pump | COP 3–5 (year-round) | 3–5 units (consistent) |
Types of Heat Pumps
Air-Source Heat Pump (ASHP)
Extracts heat from outdoor air. By far the most common type. Available as ducted systems (replaces furnace + AC) or ductless mini-splits (for individual rooms or zone-by-zone).
Ground-Source Heat Pump (GSHP / Geothermal)
Extracts heat from the ground (which stays at ~10–13°C year-round). Very high and consistent COP regardless of outdoor temperature. Higher upfront cost due to drilling or trenching.
Heat Pump Water Heater (HPWH)
A standalone appliance that replaces your electric water heater tank. Uses the same heat pump principle — COP of 3–4. Uses 60–70% less electricity than a standard electric tank. The single most cost-effective heat pump upgrade for most homes.
Calculate heat pump running costs
Compare heat pump vs. gas furnace vs. electric heat — enter your energy prices and see annual savings.
Is a Heat Pump Worth It for Your Home?
Whether a heat pump saves money vs. gas heating depends almost entirely on the ratio of your electricity rate to your gas rate. Here's the break-even rule of thumb:
| Country | Avg electric rate | Verdict vs gas | Incentives |
|---|---|---|---|
| 🇺🇸 US | $0.16/kWh | ✓ Saves vs gas in most areas | 30% federal tax credit (up to $2,000) |
| 🇬🇧 UK | £0.34/kWh | ⚠ Marginal — gas cheaper/kWh but BUS grant helps | Boiler Upgrade Scheme: £7,500 grant |
| 🇨🇦 Canada | $0.13/kWh | ✓ Often saves significantly vs gas | Canada Greener Homes up to $5,000 |
| 🇦🇺 Australia | $0.30/kWh | ✓ Saves vs gas (gas prices rising sharply) | State rebates vary — up to $3,500 in VIC |
Installation: What to Expect
A ducted air-source heat pump installation typically takes 1–3 days. A mini-split system for one zone takes about half a day. Here's what's involved:
Ducted system (whole-home)
- • Outdoor condenser unit installed on pad or wall bracket
- • Air handler replaces existing furnace in air handler/attic/basement
- • Connects to existing ductwork
- • Electrical service to outdoor unit (240V)
- • Total cost: $5,000–$15,000
Mini-split (ductless, per zone)
- • Outdoor compressor unit
- • Indoor wall-mounted air handler per zone
- • Small refrigerant line through wall (~3" hole)
- • No existing ductwork needed
- • Single zone: $1,500–$4,000 / Multi-zone: $5,000–$15,000
What to ask your installer
- →Is your system ENERGY STAR certified? (Required for federal tax credit in US)
- →What HSPF2 / SEER2 ratings does the unit have? (Higher = more efficient)
- →What is the minimum operating temperature? (Want −15°C / 5°F or lower for cold climates)
- →Does my electrical panel need upgrading? (Heat pumps need 240V/30–50A circuit)
- →Will you apply for available rebates on my behalf?
Frequently Asked Questions
Do heat pumps work in cold weather?
Modern cold-climate heat pumps work efficiently down to -15°C (5°F) and continue to operate (at reduced efficiency) down to -25°C (-13°F). Models from Mitsubishi, Bosch, and Carrier are specifically designed for harsh winters. The COP drops as temperatures fall, but still typically exceeds 1.5 even at -10°C, making them more efficient than electric resistance heating.
What is a heat pump's COP and why does it matter?
COP (Coefficient of Performance) is the ratio of heat produced to electricity consumed. A COP of 3 means the heat pump delivers 3 units of heat for every 1 unit of electricity. Traditional electric heaters have a COP of exactly 1.0. Gas furnaces have effective COP around 0.8–0.95. So a heat pump with COP 3 is 3× more efficient than an electric heater and about 3× better than a gas furnace per unit of energy cost.
Can a heat pump both heat and cool?
Yes — this is one of the biggest advantages. Most heat pumps work as air conditioners in summer (running in reverse) and heaters in winter. A single system replaces both your furnace and central AC. Ducted heat pumps replace both entirely; mini-split systems work room-by-room without ducts.
How much does a heat pump cost to install?
A ducted central heat pump (replacing a gas furnace + AC) typically costs $5,000–$15,000 installed in the US. A single-zone mini-split runs $1,500–$4,000 installed. Multi-zone mini-splits are $5,000–$15,000. After US federal tax credits (30%, up to $2,000), Canadian and UK subsidies, the net cost is often 25–45% lower.
Is a heat pump cheaper to run than a gas furnace?
In most cases yes, but it depends on your gas and electricity prices. As a rule of thumb: if your electricity rate ($/kWh) is less than 3.5× your gas rate ($/therm or per equivalent unit), a heat pump with COP 3 will be cheaper to run than a 90%-efficient gas furnace. Use our heat pump running cost calculator to model your specific situation.