Heat Pumps
Heat pumps are the fastest-growing heatypes of heating systems ting technology in North America — and for good reason. Unlike combustion-based systems that burn fuel to create heat, heat pumps move thermal energy from one place to another using a refrigeration cycle. The result is an efficiency multiplier: where a high-efficiency gas furnace converts roughly 95 cents of every dollar’s worth of fuel into heat, a heat pump can deliver $2 to $4 of heat for every dollar of electricity consumed. best time to replace a furnace mini split vs central airThat physics advantage is reshaping how homeowners think about heating and cooling.
This guide covers the three major heat pump types, how the refrigeration cycle works in practice, efficiency ratings and what they mean, cold-climate performance, and current installation costs — including how to take advantage of the federal tax credits available through the Inflation Reduction Act.
What Are the Different Types of Heat Pumps?
The three main categories of heat pumps are air-source heat pumps, ground-source (geothermal) heat pumps, and ductless mini-split heat pumps — each with distinct installation requirements, efficiency profiles, and applicable use cases. Learn more about heat pump types →
Air-Source Heat Pumps
An air-source heat pump (ASHP) transfers heat between your home and the outside air. Even cold air contains thermal energy — the refrigeration cycle extracts that energy and deposits it inside your home. In summer, the cycle reverses to provide cooling.
Air-source heat pumps are by far the most common type, accounting for the vast majority of residential heat pump installations. They’re simpler and less expensive to install than ground-source systems, and modern units perform reliably in climates that once made heat pumps impractical.
The typical air-source heat pump consists of an outdoor unit (containing the compressor, fan, and coil) connected to an indoor air handler (which distributes conditioned air through ductwork). A single outdoor unit can serve one or multiple indoor units depending on system design.
Ground-Source (Geothermal) Heat Pumps
A ground-source heat pump — commonly called a geothermal heat pump — draws heat from the earth or from a body of water rather than from outdoor air. Because ground temperatures remain relatively stable year-round (roughly 45–55°F at shallow depths), geothermal systems maintain their rated efficiency regardless of how cold it gets outside. There’s no efficiency cliff in arctic conditions the way there is with air-source units.
Geothermal systems consist of a ground loop — a buried network of high-density polyethylene piping circulating water or an antifreeze solution — connected to a heat pump unit inside the home. The ground loop can be installed horizontally in a trench (the most common), vertically in boreholes (used when yard space is limited), or in a nearby pond or well.
The ground loop represents the largest portion of a geothermal installation cost. Installing a proper ground loop for an average home typically runs $10,000–$25,000 depending on loop type, soil conditions, and lot size. The heat pump unit itself costs $4,000–$8,000. Total installed costs of $15,000–$30,000 are common.
However, operating costs are substantially lower than any other heating technology — 40–60% lower than conventional systems — and the ground loop carries a 25–50 year warranty on most manufacturers. A geothermal system can pay for its premium installation cost in 7–15 years through energy savings, and often saves $40,000–$60,000 over the system’s 20-year lifespan compared to electric resistance heating.
Ductless Mini-Split Heat Pumps
A ductless mini-split heat pump (often just called a “mini-split”) is an air-source heat pump that doesn’t use ductwork to distribute conditioned air. Compare mini-splits vs central air →
Mini-splits solve a problem that whole-house heat pumps can’t: homes without ductwork. Old homes without central air, room additions, garage workshops, basements, and home offices can all be served by a ductless system without the cost and disruption of installing ductwork.
A single outdoor unit can support up to 8 individual indoor units in a multi-zone configuration, each with its own thethermostat settings for efficiency rmostat. This zoning capability means you’re only heating or cooling the rooms in use. Energy savings from zoning alone can run 15–25% compared to a single thermostat controlling a whole-house system.
Mini-splits are also preferred for their quiet operation — the indoor units are whisper-quiet compared to the noise of a forced-air blower — and their aesthetic flexibility, with slim profiles and clean lines that blend into most room designs.
How Does a Heat Pump Heat and Cool Your Home?
A heat pump heats and cools your home by moving thermal energy rather than generating it through combustion, using the same refrigeration cycle as a central air conditioner but operating in both directions. The key components — a compressor, expansion valve, and two coil assemblies — work together to move heat in whichever direction the thermostat demands.
The Refrigeration Cycle in Heating Mode
In heating mode, the cycle works as follows:
- Evaporation: Cold liquid refrigerant (typically R-410A or newer refrigerants) passes through the outdoor coil (the evaporator). Even cold outdoor air contains heat energy, which the refrigerant absorbs. This causes the refrigerant to evaporate into a low-pressure gas.
- Compression: The gaseous refrigerant is drawn into the compressor, which increases its pressure. As pressure rises, the refrigerant heats up — substantially. A compressor can raise refrigerant temperature from roughly 35°F to 150°F or higher in a matter of seconds.
- Condensation: This hot, high-pressure gas passes into the indoor coil (the condenser). Indoor air blown across the coil absorbs the heat from the refrigerant, warming your home. The refrigerant condenses back into a liquid as it releases this heat.
- Expansion: The liquid refrigerant passes through an expansion valve, which drops its pressure dramatically. This causes it to cool back to its starting temperature, and the cycle repeats.
The critical insight is that the compressor does most of the heavy lifting. The heat energy delivered to your home comes primarily from outdoor air (in an ASHP) or from the ground — not from the electricity running the compressor. Electricity is the “payment” that makes the heat transfer happen, but it’s not converted directly into heat the way it is in an electric resistance heater.
The Reversal for Cooling
In cooling mode, a reversing valve changes the direction of refrigerant flow. Heat is absorbed from indoor air and expelled outdoors. The same components — outdoor unit, indoor air handler or units, refrigerant lines — serve both heating and cooling, which is why a heat pump is effectively a two-in-one climate control system at marginal additional cost versus a central air conditioner.
What Is the Efficiency Rating for a Heat Pump?
Heat pump efficiency is measured in two ways: HSPF (Heating Seasonal Performance Factor) for heating efficiency, and SEER (Seasonal Energy Efficiency Ratio) for cooling efficiency. Both are standardized metrics that reflect real-world performance over a full season, not just ideal lab conditions.
HSPF — Heating Efficiency
HSPF measures the total heat delivered to your home over a heating season, measured in BTUs, divided by the total electrical energy consumed by the unit, measured in watt-hours. The higher the HSPF, the more efficient the heat pump is at heating.
| Efficiency Tier | HSPF Range | What It Means |
|---|---|---|
| Standard | 8.0–8.9 HSPF | Entry-level efficiency; may not qualify for ENERGY STAR |
| High Efficiency | 9.0–10.0 HSPF | Most common in mid-range and premium units |
| Ultra-High Efficiency | 10.0–13.0 HSPF | Cold-climate units; best performance in sub-freezing temps |
For comparison, the U.S. Department of Energy minimum standard is 8.2 HSPF for air-source heat pumps. ENERGY STAR certification requires 8.7 HSPF or higher for split systems.
HSPF can also be expressed as a Coefficient of Performance (COP) — the ratio of heat output to energy input — where 1 COP = 100% efficiency. A heat pump with a COP of 3.0 delivers 3 BTUs of heat per 1 BTU of electrical energy equivalent. High-efficiency air-source heat pumps typically achieve COP ratings of 2.5–4.0 depending on outdoor temperature.
SEER — Cooling Efficiency
SEER measures cooling efficiency over a typical cooling season. The higher the SEER, the more efficiently the unit operates in summer. Minimum federal standards are SEER 14–15 depending on region (northern vs. southern). Premium units reach SEER 24–30.
Why Efficiency Varies With Temperature
Unlike a gas furnace, whose efficiency is relatively constant regardless of outdoor temperature, a heat pump’s efficiency decreases as outdoor temperature drops. This is because the heat source — outdoor air in an ASHP — becomes progressively colder, meaning there’s less heat energy available to extract.
At 47°F outdoor temperature, a modern ASHP might deliver 3–4 kWh of heat per 1 kWh of electricity (COP 3–4). At 17°F, output might drop to 2–2.5 COP. At 0°F, efficiency may fall to 1.5–2.0 COP — still better than electric resistance heat (1.0 COP by definition) but significantly reduced from rated performance.
This efficiency decline is why cold-climate heat pumps — units specifically engineered to maintain higher COP at low temperatures — have become the growth category in northern markets. Learn about cold-climate heat pump performance →
How Well Do Heat Pumps Work in Cold Climates?
Modern cold-climate heat pumps work effectively in temperatures as low as -15°F to -20°F, though their heating output and efficiency decrease progressively as temperatures drop below freezing. The days when heat pumps were impractical north of Zone 6 are largely over — but the performance trade-offs in extreme cold are real and worth understanding.
The Cold-Climate Performance Reality
In moderate winter conditions (above 30°F), a cold-climate heat pump typically outperforms a gas furnace on efficiency. Compare heat pumps vs gas heating →
By 20°F, many standard heat pumps reach their balance point against gas — meaning the cost per BTU of heat delivered is roughly equivalent. Below that temperature, supplemental heating kicks in for some units (electric resistance backup strips that heat air directly), which erodes the efficiency advantage.
Cold-climate certified heat pumps (designated by the Northeast Energy Efficiency Partnerships as “cold climate” units) maintain performance down to -15°F with better compressor designs, larger heat exchanger coils, and variable-speed compressors that can ramp up output without cycling. Many can heat a home at 0°F at 2.0+ COP — still twice the efficiency of electric resistance heat.
Hybrid (Dual-Fuel) Systems
In regions with very cold winters (Zones 4 and colder), the most cost-effective approach is often a dual-fuel hybrid system — pairing an air-source heat pump with a gas or propane furnace. The heat pump handles heating in mild weather (above the balance point temperature, typically 25–35°F), and the furnace takes over when temperatures plunge.
This approach captures the efficiency benefit of the heat pump for roughly 70–80% of heating needs in a typical northern home while maintaining furnace-level heat output on the coldest days. Total system cost is comparable to a premium single-system setup, with better year-round performance in extreme climates.
Defrost Cycles
When outdoor temperatures are near or below freezing and humidity is high, frost accumulates on the outdoor coil. Heat pumps manage this with a defrost cycle — a short reversal of refrigerant flow that sends warm refrigerant to the outdoor coil, melting accumulated ice. During defrost, the heat pump temporarily stops producing indoor heating (some units use electric resistance strips to maintain indoor heat during defrost).
Modern defrost controls are highly sophisticated, monitoring frost accumulation through pressure and temperature sensors to minimize unnecessary defrost cycles. Poorly designed or maintained defrost systems can significantly impact heating performance in icy conditions.
What Does a Heat Pump Cost to Install?
A new air-source heat pump installation costs between $5,500 and $12,000 installed, depending on size, efficiency tier, and whether ductwork modifications are needed. Ground-source geothermal systems run $15,000–$30,000 installed but offer dramatically lower operating costs. Federal tax credits under the Inflation Reduction Act can offset a substantial portion of these costs.
Air-Source Heat Pump Costs
| Equipment Tier | Equipment Cost | Installed Cost |
|---|---|---|
| Standard Efficiency (8–9 HSPF, 14–15 SEER) | $2,000–$4,000 | $5,500–$8,000 |
| High Efficiency (9.5–10 HSPF, 16–20 SEER) | $3,000–$5,500 | $7,000–$10,000 |
| Cold-Climate / Ultra-High Efficiency (10.5+ HSPF, 22+ SEER) | $4,000–$7,000 | $9,000–$13,000 |
Costs assume a single-zone or standard multi-zone installation for a 2,000 sq ft home with existing ductwork. Multi-story homes, homes without ducts (requiring mini-split installations), or homes requiring electrical panel upgrades add to the base cost.
Geothermal Heat Pump Costs
| System Type | Equipment Cost | Installed Cost |
|---|---|---|
| Horizontal Trench Loop | $4,000–$8,000 | $15,000–$22,000 |
| Vertical Borehole Loop | $4,000–$8,000 | $18,000–$30,000 |
| Pond Loop | $4,000–$8,000 | $14,000–$22,000 |
The ground loop is the cost variable that makes geothermal installation site-specific. Rocky or sandy soil, limited land area, and high water table all affect loop installation cost. A geotechnical evaluation before installation is essential.
Federal Tax Credits — IRA
The Inflation Reduction Act (IRA) provides substantial federal tax credits for heat pump installations:
- Air-source heat pumps: Up to $2,000 per unit (30% of installed cost up to that cap, through 2032)
- Geothermal heat pumps: Up to $9,500 per household (30% of installed cost with no upper cap through 2032, though the credit phases down after 2032)
To qualify, the heat pump must meet or exceed the regional efficiency requirements established by the Consortium for Energy Efficiency (CEE). The CEE cold-climate specification — requiring at least 12 HSPF and 1.75 COP at 5°F — is the standard most installers use for qualifying installations.
These tax credits make the economics of heat pump adoption substantially stronger than they appear at face value. A $10,000 heat pump installation may cost only $8,000 after tax credits — bringing the payback period well within a typical homeowner’s planning horizon.
Frequently Asked Questions
How long do heat pumps last?
A well-maintained air-source heat pump lasts 12–17 years on average, with premium units in moderate climates sometimes reaching 20 years. Geothermal systems are substantially more durable — the ground loop carries a 25–50 year warranty from most manufacturers, and the indoor heat pump unit typically lasts 20–25 years. Heat pumps generally require less maintenance than combustion systems because they have fewer mechanically stressed components.
Do heat pumps require ductwork?
No — ductless mini-split heat pumps operate without any ductwork, making them ideal for homes without existing forced-air systems. Traditional air-source heat pumps use ductwork in the same way a central air conditioner does, connecting to the home’s existing duct network. If you’re replacing a furnace with an air-source heat pump, the existing ducts can typically be used without modification.
Are heat pumps expensive to run in cold weather?
Heat pumps become more expensive to operate as outdoor temperature drops, but they remain more efficient than electric resistance heat even at very low temperatures. In extremely cold conditions where the outdoor temperature falls below the heat pump’s effective operating range, supplemental electric resistance heating activates — at 1.0 COP, this is three to four times more expensive per BTU than the heat pump’s rated performance. A cold-climate heat pump in a dual-fuel system that switches to a gas furnace below a certain temperature avoids this problem entirely.
Can a heat pump cool my home in summer?
Yes — one of the primary advantages of a heat pump is that it provides both heating and cooling from the same equipment, at no additional installation cost versus a central air conditioner. The refrigeration cycle reverses to absorb heat from inside your home and release it outdoors, just like a central air conditioner. SEER ratings (cooling efficiency) are included in the heat pump’s performance specifications. Using a heat pump for summer cooling rather than a separate AC unit simplifies home mechanical systems and reduces maintenance burden.
What is the best heat pump for cold climates?
The best heat pumps for colheat pump efficiency in cold climates d climates are those certified under the Northeast Energy Efficiency Partnerships (NEEP) cold-climate specification, which requires a minimum COP of 1.75 at 5°F outdoor temperature and HSPF of 12 or higher. Brands like Mitsubishi, Fujitsu, Carrier, Trane, and Bosch all offer cold-climate certified units that maintain effective heating in temperatures as low as -15°F to -20°F. When selecting a cold-climate unit, look specifically for the “cold climate” designation rather than relying on the standard HSPF rating, which is measured at the milder 47°F outdoor temperature.
