How Much Does Air Conditioning Installation Cost in Carshalton?

The short answer

There is no single price for air conditioning installation, and any website quoting one figure for every home is guessing. The cost of your installation is driven by the number of rooms, the capacity of the units, how far the pipework has to travel, where the outdoor unit can go, whether condensate can drain by gravity, and what electrical work is needed.

We do not publish example prices on this website because a figure taken out of context is misleading. What we can do is explain exactly what a surveyor is assessing, so that when you compare written quotations you know what you are comparing.

How many rooms, and how many units

The single biggest factor is how many indoor units you need. One indoor unit controls one room. If you want cooling in two bedrooms and a loft office, that is three indoor units, whether they run from three separate outdoor units or one shared condenser on a multi-split system.

A single-split installation (one indoor, one outdoor) is the simplest and lowest cost per room. Multi-splits reduce the number of outdoor units but add pipework, refrigerant volume and labour, so the saving is not always as large as people expect.

Capacity and correct sizing

Capacity is quoted in kilowatts, and larger units cost more. But sizing is not simply a matter of buying the biggest unit that will fit. An oversized system short-cycles, controls humidity poorly and can be noisier in use; an undersized one runs continuously and never reaches the temperature you set.

A proper survey establishes room dimensions, glazing area and orientation, insulation, ceiling height, occupancy and equipment heat. That is why we survey rather than quote from a room name.

Pipe runs, routes and making good

Refrigerant pipework connects the indoor and outdoor units, and its length and route make a real difference to labour. A bedroom on an external wall with the condenser directly outside is a short, simple run. A loft room with the condenser at ground level at the front of the house is not.

Where pipework is run internally, there may be lifting of floorboards, boxing in or redecoration to consider. Where it runs externally, trunking is used, and the quality of that trunking work is one of the clearest differences between a careful installer and a rushed one.

• Distance between indoor and outdoor unit
• Number of bends and floor levels crossed
• Internal routing through voids, or external trunking
• Access equipment where working at height is needed

Condensate and electrical work

Cooling produces condensate, which has to be taken away. If there is a gravity route to a suitable external drain, this is straightforward. If not, a small condensate pump is added, which increases cost slightly and needs a power supply.

Electrically, systems normally need a suitably rated supply and isolation. Some installations can use a nearby existing circuit; others need a new dedicated circuit from the consumer unit, which is a bigger job. This is checked at survey so it appears in the quotation rather than as a surprise later.

Comparing quotations sensibly

When you have two or three quotations, compare the scope rather than the headline number. Check the make, model and capacity of each unit, the stated indoor and outdoor positions, whether trunking and making good are included, whether electrical work is included, and whether commissioning and handover documentation are provided.

Also check that the installer is F-Gas registered. Handling refrigerant requires certification; WDI Group (Surrey) Ltd is REFCOM registered under REF1021486.