A heat pump moves heat instead of making all of it through electrical resistance. In winter, an air-source system transfers heat from outdoor air into the home. In summer, it reverses that job and transfers indoor heat outdoors. The outdoor unit needs open airflow, so making it less noticeable must never mean wrapping it in a decorative box.
This guide explains the heating cycle in four steps, shows how to compare running costs, and offers five ways to soften the view without blocking the equipment. It concerns space heating and cooling; a heat-pump water heater is a different installation with its own requirements.
How a heat pump works in 4 steps
1. Collect outdoor heat. Cold, low-pressure refrigerant passes through the outdoor coil and absorbs heat from the surrounding air. Outdoor air still contains thermal energy below freezing. The refrigerant evaporates as it absorbs energy; the fan helps move air over the coil.
2. Raise the temperature. An electrically driven compressor increases the refrigerant’s pressure and temperature. This is why a heat pump needs electricity even though much of the heat it delivers comes from its surroundings.
3. Release heat indoors. The hot refrigerant gives up heat through the indoor heat exchanger and condenses. A ducted or ductless air system distributes that heat into rooms; an air-to-water system transfers it into a water-based heating circuit.
4. Reduce pressure and repeat. An expansion device lowers the refrigerant’s pressure before it returns to the outdoor side. The cycle continues under the system’s controls. In cooling mode, the indoor and outdoor coils exchange roles; the system removes heat from your rooms.
What “three units of heat from one unit of electricity” means
The coefficient of performance, or COP, is useful heat output divided by electrical input under stated conditions. At an assumed COP of 3, 1kWh of electricity delivers 3kWh of heat. That is not energy created from nothing: the system transfers outdoor heat as well as using electricity. Nor is COP 3 a promise for every hour of the year.
Outdoor temperature, indoor or water-temperature targets, defrost cycles, installation quality and auxiliary heating change performance. Compare seasonal estimates for your climate and actual heat emitters, not one attractive test-point COP. Ask what is included in the estimate: fans, pumps and backup heaters may materially affect the total.
Worked example: cost per unit of useful heat
Assume electricity costs $0.18/kWh and your home needs 30kWh of useful heat over a particular period. At COP 3, the heat pump uses 30 ÷ 3 = 10kWh, costing $1.80. At COP 2, it uses 15kWh, costing $2.70. A resistance heater at an idealized COP of 1 uses 30kWh, costing $5.40. These are transparent examples, not a household forecast.
| Assumed heating performance | Electricity for 30kWh heat | Cost at $0.18/kWh |
|---|---|---|
| Heat pump, COP 3 | 10kWh | $1.80 |
| Heat pump, COP 2 | 15kWh | $2.70 |
| Resistance heat, COP 1 | 30kWh | $5.40 |
A gas comparison needs a different calculation: divide the gas energy price by the boiler or furnace efficiency to obtain cost per useful kWh of heat. Include fixed charges only if the fuel service can actually be discontinued. A heat pump can use less purchased energy without necessarily being cheaper than every local gas tariff.
Will an air-source heat pump work below freezing?
Yes, suitable equipment can. ENERGY STAR distinguishes cold-climate systems designed for low outdoor temperatures. The important question is whether the selected model can deliver your home’s required heat at its local design temperature—not whether a brochure says it operates at that temperature. Operating range and heating capacity are different specifications.
Ask the installer for a room-by-room load calculation, low-temperature capacity, the expected backup-heating contribution and the control strategy. A system can be running normally while still needing supplemental heat. Insulation and air leakage influence the demand it must meet; our electric bill and small improvements guide helps separate household demand from equipment efficiency.
5 ways to hide an outdoor heat pump without restricting it
1. Choose a less visible location during design. Ask the installer about an appropriate side elevation instead of the main patio view. Refrigerant or water-pipe routes, drainage, noise, service access and permitted siting still take priority. Moving an installed unit solely for appearance can be a substantial project.
2. Use a distant screen to interrupt the sightline. A separate screen can sit between your seating area and the unit without enclosing it. Have the installer approve the location against the exact manual’s intake, discharge, overhead and service clearances. “Slatted” does not automatically mean enough airflow.
3. Plant a border outside the required clear zone. Choose the position using the plant’s mature size, not the pot size at purchase. Leave room for pruning, falling leaves and access. Avoid vines that can grow into the grille or a hedge that becomes a solid wall in front of the fan.
4. Shift the visual focus elsewhere. A seating area, attractive planter or garden feature can draw the eye away from equipment while leaving the heat pump entirely uncovered. This is often more practical than building something around a machine that must breathe and be serviced.
5. Coordinate the surrounding hardscape. A tidy base, an installer-approved pipe-cover route and coordinated nearby fencing can make the installation look intentional. Keep drainage and service routes clear. Do not paint coils, grilles, labels or the equipment enclosure unless the manufacturer expressly permits the treatment.
Cover, screen or leave open?
| Idea | Decision |
|---|---|
| Tight box, lid or decorative wrap | Do not use on an operating unit unless the exact accessory is approved for that equipment. |
| Screen or planting away from the unit | Only after model-specific airflow, access and drainage checks. |
| Manufacturer-approved snow accessory | Ask the installer whether your site needs it and how it must be fitted. |
| Open, tidy installation | Usually the simplest starting point; manage sightlines elsewhere. |
There is no single clearance distance that applies to every unit or arrangement. The front of one model may discharge air while another uses a different airflow path. Multiple walls or units can change the manufacturer’s rules. Ask for the relevant manual page and draw the clear area onto your landscaping plan before purchasing materials.
Questions to put in the installation quote
Request the exact indoor and outdoor model numbers, sizing assumptions, duct or emitter work, electrical work, condensate/defrost drainage arrangements and commissioning records. Ask who checks noise and planning requirements, how filters are maintained and how you will recognize auxiliary heat. A clear handover is more valuable than a vague annual savings promise.
If backup power is part of the plan, use electrical input and startup requirements—not heat-output kW—to size it. Auxiliary heating can change the load sharply. Our home battery runtime guide explains why usable energy and power output must both be checked.
The short version
A heat pump collects, compresses, releases and recirculates heat. Its real cost depends on climate, system design and tariffs. For appearance, screen the view at a distance or improve the surroundings; preserve the airflow and access specified for the actual unit.
References reviewed November 14, 2026: ENERGY STAR air-source heat pumps; ENERGY STAR cycle explanation; Mitsubishi Electric outdoor-unit maintenance guidance. The featured scene is conceptual, not a clearance drawing or installation specification.
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