Air conditioning installation in London

Is air conditioning right for your home?

Air conditioning is worth fitting when a room stays too hot to sleep or work in, and blinds, shade and fans haven’t fixed it. These are the usual signs:

• a bedroom stays hot through the night, even with the windows open
• a home office is too warm to work in by mid-afternoon
• a loft conversion or top-floor flat traps the heat
• traffic noise or security keeps the windows shut
• you want a room heated as well, from the same unit

Most split systems heat as well as cool, so a unit can earn its keep all year. Used for heating, they’re called air-to-air heat pumps.

London summers are getting hotter, which is why more homes are asking the question. What the next ten years could bring.

Which system suits your rooms

The right system depends on how many rooms need cooling and where an outdoor unit can go:

• One room: a single split, with one indoor unit and one outdoor unit.
• Several rooms: a multi-split, with several indoor units on one outdoor unit.
• A whole floor or a refurbishment: a ducted system, with the units hidden above the ceiling.
• No room for an outdoor unit: a through-the-wall or water-cooled unit may work instead.

These guides go further: the main kinds compared, one outdoor unit or several, and options with no outdoor unit.

Rooms and homes we fit

Most London homes can take air conditioning, but each kind of room brings its own questions:

• Bedrooms, where quiet running matters most.
• Loft conversions, where the roof traps the heat.
• Flats, where the freeholder has a say.
• Conservatories, where glass makes the room swing from hot to cold.
• Open-plan rooms, where one unit may not reach every corner.
• Offices and shops, where the job is planned around your hours.

High-end homes and full refits

Air conditioning in a high-end home or a full refit works best when it’s planned before the ceilings go up. That gives you more choice, and three things change:

• The units can be hidden: above a ceiling or behind a panel, so the room shows little more than a slim grille. Ways to hide a unit.
• One design can cover every room: how to cool a whole home and what a ducted system needs.
• Permissions come first: a listed home, a conservation area or a big estate can each add a step. See Westminster and Kensington and Chelsea.

If an architect or designer is running the job, we’ll work from their drawings.

What we check at the survey visit

The survey visit settles what the job needs, so your written quote has no guesswork in it. The engineer looks at:

• the size of each room and how much sun it gets, which sets the size of unit you need
• where the outdoor unit can go, and how it affects your neighbours
• the pipe route between the units, and how to keep it neat
• how the water from the indoor unit drains away
• your electrics, and whether the unit needs a new circuit
• access for the job, including stairs, ladders or scaffolding
• any permission you need first, from a freeholder or the council

A new electrical circuit is notifiable work under Part P of the Building Regulations, so it has to be done and signed off properly.

What happens on installation day

Installation day runs in four stages: the indoor unit, the pipes, the outdoor unit, then testing. A single unit in one room usually takes half a day to a full day. A system for several rooms usually takes one to three days.

Fixing the indoor unit

The indoor unit hangs on a plate fixed high on the wall. A hole through the wall carries the pipes, the cable and the drain. The floor and furniture are covered first, and the dust is cleared up afterwards.

Running the pipes and trunking

Pipes run from the indoor unit to the outdoor unit. They can often be hidden in a wall, a cupboard or a ceiling. Where they can’t, trunking is a neat cover that protects them, and it can be painted to match. The survey shows which route suits your home.

Setting the outdoor unit

The outdoor unit sits on wall brackets, a flat roof or the ground, on mounts that cut vibration. It needs clear air around it, so the engineer follows the maker’s spacing.

Testing and handover

The pipes are pressure tested and cleared of air and moisture, then the system is run and checked. You’re shown how to use the controls, and you get the paperwork for your warranty.

The rules an installation must meet

Three sets of rules cover a home installation: F-gas, planning and the Building Regulations.

• F-gas: the engineer needs an F-gas qualification, and the company needs its own F-gas certificate. What F-gas certification means.
• Planning: a unit that cools without heating usually needs planning permission. A unit that heats as well can often go ahead without it on a house, within limits. How planning works for air con.
• Building Regulations: fixed air conditioning counts as building work, and a new electrical circuit is notifiable under Part P.

Leases add a fourth check. A leaseholder needs the freeholder’s permission before anything is fixed to an outside wall.

Sources: GOV.UK on F-gas, the planning order, the Building Regulations and the Leasehold Advisory Service.

How an installation is priced

An installation is priced on the rooms, the outdoor unit’s position and the length of the pipe run. Every job gets a written quote after the survey. The cost guide sets out what moves the price.

Keeping it running after it's fitted

A yearly service keeps a new system clean, quiet and efficient. It isn’t a legal requirement for a typical home system, but some makers’ warranties ask for one, so check yours. What a service covers.

When air conditioning isn't the answer

Air conditioning isn’t the answer if simpler fixes will do, or if the building rules it out. We’ll say so at the survey if that’s the case:

• a room that gets hot for a few afternoons a year may do better with blinds, shading and a fan
• a lease that bans anything on the outside walls may rule out a split system, though options with no outdoor unit can still work
• a listed building may need consent that takes longer than the summer you’re planning for