Air-to-air heat pumps in Ilford

How can cold outdoor air heat a room?

Air well below room temperature still carries heat, and a heat pump moves that heat rather than making it. In heating mode the outdoor coil is chilled below the temperature of the air passing over it, so warmth flows into the refrigerant even on a winter morning. Compressing that vapour raises its temperature above the room's, and the indoor coil then releases the heat to the air you sit in. A reversing valve sends the cycle the other way in summer, which is why the same pair of units cools in July. Because the electricity drives a pump instead of a heating element, every kilowatt-hour it uses delivers several of warmth.

How efficient are air-to-air heat pumps?

Highly, on paper. The Energy Saving Trust puts typical seasonal heating performance (SCOP) above 4.0, so more than four kilowatt-hours of heat for each one of electricity across a heating season, and typical seasonal cooling performance (SEER) at around 7.0. Its slides also quote a COP of 6.2 for a 2.6kW unit at 35°C outdoors and 27°C indoors. Better units rate higher: Mitsubishi Electric lists a SCOP of 5.2 for its 2.5kW MSZ-LN25VG2. These are test figures. The Trust's own advice page says there is not much data on how air-to-air systems perform in UK homes, so read any rating as an upper limit. Sources: Energy Saving Trust slides; Energy Saving Trust advice; Mitsubishi Electric.

What does a unit of heat cost on the current price cap?

The unit rates are Ofgem's Direct Debit averages for 1 October to 31 December 2026, with an electricity standing charge of 54.83p a day. The cap for January to March 2027 is due on 25 November 2026 (Ofgem, August 2026), and your own tariff may differ. The division is ours, not Ofgem's or the Energy Saving Trust's. Next to plug-in electric heaters the saving is large; set against gas the margin is slim, and it turns on the particular unit and the way you run it. The running costs guide covers summer use as well. Sources: Ofgem; Energy Saving Trust.

Which homes in Ilford suit an air-to-air heat pump?

Smaller homes and flats above all, which the Energy Saving Trust singles out as a good fit. Flats are a large share of Redbridge: 25.36% of households live in purpose-built blocks and 6.55% in converted houses, according to the 2021 Census. They also suit:

• rooms the central heating barely reaches, such as a loft conversion or a rear extension;
• garden offices and studios that have no heat source yet;
• a room you want cooled in summer as well, so one unit earns its keep all year.

Winters here are mild but not frost-free. The Met Office's long-run averages for Greenwich, about six miles away, show air frost on roughly 23 days a year, so a unit you rely on for heat is sized for those mornings rather than the average one. Sources: Energy Saving Trust advice; Census 2021 via Area Insights; Met Office.

Will it replace my boiler?

Not for hot water, and rarely for a whole house. In the Energy Saving Trust's words, air-to-air heat pumps do not usually provide hot water for taps and showers, so the boiler or cylinder stays. Each indoor unit warms the air in its own room, and rooms without one still need radiators or another heater. In a flat of two or three rooms, a multi-split can reach most of the living space from one outdoor unit. Source: Energy Saving Trust advice.

Why does heating use matter for planning?

Because permitted development in England now depends on it. Since 29 May 2025 the householder right for heat pumps has excluded units run purely for cooling, so a reversible unit used for heating can qualify where a cooling-only one cannot. The same order lifted a house's size limit for the unit to 1.5 cubic metres, allowed two units on a detached house and dropped the old one-metre gap from the boundary. Planning Portal adds that the unit must be removed once it is no longer needed for microgeneration. Rules for flats, listed buildings and conservation areas are in the planning guide. Sources: Baxi; Planning Portal; SI 2025/560.

What does an air-to-air system cost to install?

The Energy Saving Trust's research puts it at around £1,900 for a single room and around £3,700 for a three-bedroom semi, and it warns of extras such as redecorating afterwards. Those are national figures, not our prices: we quote after measuring the rooms and the route. How we survey and price around the town is set out under Ilford heating and cooling. Source: Energy Saving Trust advice.