Air conditioning questions, answered briefly

Send the form with your postcode and the rooms, or ring 020 8194 3009. We call back, and if the job looks possible we book a survey and quote in writing.

Checkatrade's May 2026 figures give £750 for a 12,000 BTU unit and £1,150 to fit it, with electrics adding £400 to £700. The cost guide breaks it down.

Checkatrade says 20p to 60p an hour. Our cost guide works it out from the current price cap and gets about 9p an hour for a 2.5kW unit holding temperature.

One of them is probably missing the electrics, the access equipment, extra pipe, the consents or a company F-gas certificate. Check all five.

A reversible unit heats the room it is in by running in reverse. See air-to-air heat pumps.

Considerably. At a seasonal efficiency of 4, each kilowatt-hour of heat costs about a quarter of what a plug-in heater charges.

No. Taps and showers stay with the boiler or the cylinder.

Roughly 2.0 to 2.5kW for a 15 to 25 square metre room, more for glass, height or a top floor. See the size guide.

Almost always, and a new circuit in a home is notifiable work under Part P, so a registered electrician does it and certifies it.

Yes, with a multi-split, which is the usual design for a terrace or a semi.

Normally, given a tall enough wall and a route down for the pipes. The loft guide explains.

A monobloc unit breathes through two wall grilles and needs no outdoor box. Here is how they work, limits included.

For a rented room or a stopgap, often yes. Our comparison is candid about it.

The freeholder, in writing, before anything else. Your lease says whether they can refuse and what they can charge. See air conditioning in a flat.

A reversible unit on a house that satisfies every permitted development condition needs none. Flats above shops, listed buildings and road-facing walls in conservation areas need an application. See the planning guide.

No unit on a wall or roof facing the road, and nothing nearer the road than the house. Croydon has 21 such areas.

To stay within permitted development, the calculation next to the neighbour's nearest door or window has to give 37 dB(A) or below.

There is not. The law asks for a reasonable temperature and for employers to assess heat as a risk. See office air conditioning.

A five-yearly energy inspection, required once the air conditioning under one person's control exceeds 12kW.

Yearly for most homes, in spring. Busy shops and salons may need two. See servicing.

Probably a blocked condensate drain. Turn it off, catch the water and see repairs.

No. A sealed system keeps its charge. Low gas means a leak, and the leak gets fixed first.

Yes. The make and model help, but we can work without them.

All of Croydon, plus Bromley, Beckenham, Sydenham, Sutton, Banstead, Mitcham, Streatham, Coulsdon and the places between. Every one is named on the areas page.

Possibly. Ring 020 8194 3009 or put it on the form, and we will say either way.