Cool in July, warm in January — from one unit

Every installation is priced after a free survey, because the cost depends far more on the property than on the unit — how far the pipework has to run, where the outdoor unit can sit, and whether access needs scaffolding. What you are quoted covers the indoor and outdoor units, refrigerant pipework, drainage, the electrical connection, core drilling, making good, commissioning and registering the warranty.

Yes, and this is the part most people do not realise. An air conditioner does not make cold — it moves heat from one side of a wall to the other. Run it in reverse and it moves heat into your home, delivering roughly three units of warmth for every unit of electricity it uses. That makes it cheaper to run than an electric heater and often cheaper than extending your central heating to reach an awkward room.

A single-room system is usually a day. A multi-room system is typically two to three days, depending on how far the refrigerant pipework has to run and how easy the outdoor unit is to position.

Usually not. Most domestic installations in England fall under permitted development, though there are conditions about the size of the outdoor unit, how close it sits to a boundary and noise at the neighbouring property. Listed buildings and conservation areas are the exception and normally do need consent. We check your address before quoting and will tell you if yours is affected.

A modern inverter unit indoors runs at roughly the volume of a quiet conversation on its lowest setting, and inverter units spend most of their time on a low setting because they modulate rather than switching hard on and off. People routinely sleep with them running. The outdoor unit makes a low hum, which is why where it sits matters — particularly relative to a neighbour's bedroom window.

Cooling a typical bedroom costs a few pence an hour. In heating mode it is normally cheaper per unit of warmth than an electric heater, because it moves heat rather than generating it.

Once a year. Filters and coils clog with dust, which quietly kills both the efficiency and the air quality. We can include it in a maintenance plan alongside your boiler so it is one visit rather than two.

Sometimes. Electricity costs considerably more per unit than gas, but a heat pump delivers around three times the energy it uses. In a well-insulated house that comes out ahead. In a draughty one it does not, and we will tell you which yours is.

We are working through MCS certification, which is what the government grant requires. Until that is in place we give honest advice on whether your home suits one and handle the insulation and radiator work that has to come first.

Yes, and it is usually the better answer. Two to five indoor units can run from a single outdoor unit, each with its own controls and temperature. It is tidier and cheaper than several separate systems.