Heating
Air conditioner or heat pump for heating: which pays off
Both are heat pumps – they take heat from outdoor air. The difference is where they deliver it: an air conditioner straight into the room air, an air-to-water heat pump into the water of your heating system. Every pro and con follows from that.
5 min readUpdated
The air conditioner as heating
An inverter unit warms a room in minutes, needs no piped installation with radiators and costs several times less upfront. For a two- or three-room apartment, two units or a multi-split system are the fastest and cheapest route to efficient heating.
Downsides: air-only heating (some people notice dryness and air movement), one indoor unit per room, and reduced output in deep cold – so pick models with good heating output at −7°C.
The air-to-water heat pump
A heat pump feeds radiators, underfloor heating or fan coils and makes domestic hot water. It heats the whole house evenly and quietly, works with low water temperatures (ideal for underfloor heating) and replaces an electric, gas or pellet boiler.
The investment is higher – the unit plus the hydraulic installation – and pays back on larger areas, in a house with an existing wet system, or in new builds. For whole-house heating from about 100 m² up, the heat pump is usually the more efficient system.
Running costs
Both deliver 3–5 kWh of heat per kWh of electricity in typical Bulgarian conditions. The heat pump wins for year-round whole-house heating because it runs at low water temperature and covers hot water too. The air conditioner wins when heating is room-by-room and hour-by-hour – you switch it off where nobody is.
Quick rule
A starting point, not a final answer – a consultation with your building plan is free.
- Apartment up to 3 rooms, no wet system → air conditioners / multi-split
- House with radiators or underfloor heating → air-to-water heat pump
- New build → heat pump with underfloor heating and fan coils for cooling
- Weekend house → air conditioner (fast warm-up, low investment)
Frequently asked questions
Can a heat pump cool in summer?
Yes, with fan coil units. Underfloor heating can cool only to a limited degree (condensation risk) and radiators not at all.
What does a heat pump for a 120 m² house cost?
It depends on capacity (usually 8–12 kW), type (monobloc or split) and the installation. Send us the area, insulation and heating type for a concrete quote.
Does an air conditioner work at −20°C?
Most inverter models run down to −15°C and dedicated heating ranges to −25°C, at reduced output. For regions with long cold spells, pick a model with high heating output at −7°C.
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