Cool in summer. Warm in winter.

It is a heat pump that moves warmth between outside air and the air inside a room, instead of heating water for radiators or a cylinder. An outdoor unit extracts heat from the air outside, even when that air is cold, and an indoor unit releases it into the room. The whole cycle is reversible, so it can run backwards too, pulling heat out of the room and releasing it outside, which is how it cools.

Yes. A reversible air conditioning system such as the ones we fit is an air to air heat pump: the same equipment cools in summer and heats in winter by running the refrigerant cycle in either direction. A cooling-only unit cannot do this, which is one reason we only fit reversible systems.

Gov.uk lists £2,500 towards an air to air heat pump under the Boiler Upgrade Scheme. The grant has to be claimed through an MCS certified installer registered for the scheme. Pro-Fit is not registered for the Boiler Upgrade Scheme, so we are not able to process it on an air conditioning installation. We would rather tell you that now than have it come up partway through a survey.

That depends on how many rooms you are having done and what the survey finds for pipe runs and electrical work, so we do not give one figure for every job here. More rooms mean more pipe runs and more electrical work, and your surveyor will confirm the likely timing for your rooms as part of the free survey.

Running the unit uses electricity, in the same way any heating or cooling appliance does, and how much depends on how often you run it and at what temperature. We do not publish a figure for this because it varies too much by home and by habit to be honest about in general terms; your surveyor can talk through how your specific rooms and glazing affect it.

You need your landlord's agreement before any outdoor unit goes up, because it is a permanent fixture on the building. We are happy to survey a rented property and give a written quote, but the agreement with the landlord is between you and them before we book the work in.

A single split system is one outdoor unit running one indoor unit, which suits a single room. A multi-split system is one outdoor unit running two or more indoor units, each controlled separately, which is how we cover several rooms without fitting an outdoor unit for every one. Our two zones and three to four room bands on this page are both multi-split.