Air conditioning installation London homeowners can plan properly starts with the room, property and outdoor-unit position rather than choosing an air conditioner from its headline kW rating alone. Let’s Heat is making London its main service area, with surrounding coverage available depending on postcode, property type and installation requirements.

For most homes, a fixed split air conditioning system gives a neater and more effective long-term solution than a portable unit. Our air conditioning installation London service covers suitable systems for flats, houses and other residential properties. The indoor unit cools or heats the room, while the outdoor unit rejects or absorbs heat outside. The correct system depends on room heat gain, glazing, insulation, occupancy, layout, noise requirements and where the refrigerant pipework and condensate can run.

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Air conditioning installation London: the quick answer

A London home can usually be cooled with a single-split system for one important room, a multi-split system for several rooms or a ducted arrangement where a more concealed finish is required. Wall-mounted split systems are the most straightforward option in many houses and flats, but outdoor-unit location, planning restrictions, leasehold consent, electrical supply, condensate drainage and noise all need checking before installation.

Many modern fixed air conditioners are reversible air-to-air heat pumps, so they can provide heating as well as cooling. This can be useful during spring and autumn, although it does not automatically mean the system should replace the home’s main heating system.

Which air conditioning system is best for a London home?

For air conditioning installation London homeowners can choose from single-split, multi-split and ducted systems depending on the property, number of rooms and available outdoor-unit positions.

System type	Best considered for	Main advantage	Main consideration
Single split	Bedroom, living room, loft room or home office	One indoor unit connected to one outdoor unit	Each additional room normally needs another system or a different layout
Multi-split	Several rooms	Multiple indoor units can connect to one outdoor unit	Pipe routes and system design become more involved
Ducted	Whole floors, premium refurbishments or homes wanting hidden indoor equipment	Only grilles are visible in the rooms	Requires suitable ceiling or void space and more installation work
Ceiling cassette	Larger open-plan rooms and some commercial spaces	Distributes air in several directions	Needs appropriate ceiling space
Portable unit	Temporary or rental situations	No permanent refrigerant installation	Generally noisier, less discreet and requires an exhaust route

Read our guides to split air conditioning, wall-mounted air conditioning and ducted air conditioning for more detail.

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How air conditioning works

A fixed split system transfers heat rather than creating “cold air”. In cooling mode, the indoor unit absorbs heat from the room and the refrigerant circuit carries that energy to the outdoor unit. In heating mode, a reversible system operates in the opposite direction and transfers heat indoors.

This is why modern room air conditioners are often described as air-to-air heat pumps. The system still needs electricity to operate, but the compressor moves heat between indoors and outdoors rather than producing all of the heat directly from electrical resistance.

Our air-to-air heat pump guide explains the heating side in more detail.

Air conditioning for London flats

Air conditioning installation London flats often requires extra consideration around outdoor-unit positioning, building permissions and access. Flats need additional planning because the outdoor unit normally affects the exterior of the building. The technically easiest indoor position is not always the position that the freeholder, landlord, managing agent or planning authority will accept.

confirm that an outdoor unit can be installed in the proposed location
check lease or freeholder restrictions before committing to the work
consider balcony, roof or external-wall access
plan condensate drainage without creating nuisance below
keep noise and vibration away from bedrooms and neighbouring windows where practical
allow future service access to both indoor and outdoor equipment

Householder permitted-development rights do not generally apply to flats in the same way as they do to houses, so planning should be checked for the specific property rather than assumed. Listed buildings, conservation areas and externally visible equipment can also require additional consideration.

Air conditioning for London houses

Houses often provide more flexibility for the outdoor unit, but the installation still needs a suitable pipe route, electrical supply and condensate drain. Bedrooms can often be served by separate small systems or a multi-split arrangement, while larger open-plan ground floors may need a different capacity and air-distribution strategy.

The outdoor unit should not simply be hidden in the most enclosed corner available. It needs enough airflow to reject or absorb heat and adequate access for future servicing.

How we size air conditioning for a room

Room floor area is useful, but it is not enough on its own. Air conditioning sizing should consider the heat entering the room and the way the space is used.

room dimensions and ceiling height
window size and orientation
solar gain
insulation level
number of occupants
computers, cooking equipment and other heat-producing appliances
whether doors are normally open to adjoining spaces
required indoor temperature
noise expectations, particularly in bedrooms

An oversized system can cycle unnecessarily and may not provide the comfort expected, while an undersized system can struggle during the hottest conditions. Selection should follow the actual room load rather than choosing the biggest unit available.

Single-split vs multi-split air conditioning

Single split

A single split has one indoor unit and one outdoor unit. It is often the simplest solution for a bedroom, loft room, living room or home office. It can also make maintenance and future replacement straightforward because each system is independent.

Multi-split

A multi-split connects several indoor units to one outdoor unit. This reduces the number of external condensers but increases the importance of pipe routing and system design. It can be attractive where outside space is restricted or appearance matters.

Neither arrangement is automatically better. The property layout, number of rooms, outdoor space, budget and maintenance preferences all matter.

Ducted air conditioning in London

Ducted systems can create a discreet finish because the fan-coil unit is hidden above a ceiling or within a suitable void and conditioned air enters the rooms through grilles. They can work particularly well during major refurbishments where ceilings are already being altered.

The trade-off is greater installation complexity. The design needs suitable void space, return-air paths, ductwork, access panels and a realistic route for refrigerant pipework and condensate.

Can air conditioning heat a London home?

Many modern split systems can heat as well as cool. This can be useful for bedrooms, home offices, extensions and shoulder-season heating because the system can raise the room temperature quickly without operating the whole central-heating system.

Whether air conditioning should become the main heating system is a different decision. It depends on the property heat loss, room layout, required outdoor-temperature performance and how occupants prefer heat to be distributed.

Where can the outdoor air conditioning unit go?

The outdoor condenser needs airflow, safe fixing, sensible pipe routes and service access. Noise and vibration should also be considered, especially in densely occupied London streets and blocks of flats.

external wall at low level where appropriate
ground-mounted position
balcony where permission and ventilation allow
flat roof where access and planning conditions allow
rear or side elevation where visual impact is reduced

The final location must follow the manufacturer’s installation requirements and any relevant planning, leasehold or building-control requirements.

Do you need planning permission for air conditioning in London?

Planning requirements depend on the property and the proposed outdoor equipment. Houses may benefit from permitted-development rights in some circumstances, but those rights have conditions and do not apply to flats in the same way. Listed buildings, conservation areas and properties with restricted development rights need additional checking.

For fixed systems, building-regulations requirements can also apply. GOV.UK specifically lists putting in a fixed air-conditioning system among alteration projects that can require Building Regulations approval. Planning permission and Building Regulations are separate matters, so a project may need one, both or neither depending on the circumstances.

F-gas requirements for split air conditioning

Split air conditioners contain refrigerant, so refrigerant work is regulated. GOV.UK states that individuals working on stationary air conditioning and heat-pump equipment containing F-gas need the appropriate qualification, and businesses servicing stationary equipment operated by others can also require company certification.

Current F-gas rules also affect which refrigerants can be used in newly placed equipment. The system selected in 2026 should therefore be a current UK-market model rather than old stock chosen only because it appears cheaper.

What affects air conditioning installation cost in London?

The cost of air conditioning installation London projects varies according to system size, pipework, electrical work, access and outdoor-unit location. We do not use one fixed article price because two installations with the same indoor unit can require very different work. The complete quotation depends on the system and the property.

single split, multi-split or ducted system
number of rooms and indoor units
required cooling and heating capacity
brand and model
length and complexity of refrigerant pipework
condensate drainage
electrical supply and isolators
outdoor-unit position
high-level access or scaffolding where required
core drilling and wall construction
decorative trunking or concealed pipework
planning, leasehold or building-management constraints
commissioning and future service access

A quotation should identify the exact indoor and outdoor models, installation position, electrical work, condensate route and any access assumptions. That makes it much easier to compare proposals properly.

Air conditioning brands we compare

There is no single best air-conditioning brand for every room. We compare current products according to capacity, noise, dimensions, control options, warranty terms and suitability for the proposed installation.

Our wider air conditioning guide explains the main system choices before you decide on a brand.

Domestic vs commercial air conditioning

This page focuses mainly on homes. Offices, shops, restaurants and other commercial buildings can have different occupancy patterns, ventilation loads, operating hours and equipment requirements. For business premises, see our commercial air conditioning installation page.

Air conditioning servicing and maintenance

A fixed system needs ongoing maintenance. Filters need cleaning, drainage should remain clear and refrigerant-side performance should be checked when required. Manufacturer warranty conditions can also specify servicing intervals.

Read our air conditioning service guide and domestic air conditioning service and repair page.

Air conditioning installation London service areas

Our air conditioning installation London coverage is focused on Greater London and surrounding areas, subject to the property, system type and installation requirements. London is becoming the main Let’s Heat service area, with jobs considered further outside London depending on postcode and engineer availability. Cardiff remains a secondary service area.

Rather than creating hundreds of near-identical location pages, we will build useful pages only for areas where Let’s Heat genuinely provides coverage and where the property or installation considerations justify local information.

Frequently asked questions

What is the best air conditioning system for a London flat?

A compact single-split or multi-split system is often the most practical fixed option. The outdoor-unit position, freeholder or landlord approval, planning position, pipe route and noise requirements should be checked before choosing the model.

Can air conditioning cool several bedrooms?

Yes. Options include separate single-split systems, a multi-split serving several indoor units or a ducted system. The best layout depends on the property and where pipework, ducts and outdoor equipment can be installed.

Can air conditioning also heat the room?

Many modern split systems are reversible and can provide heating as well as cooling. Their suitability as a main heating system needs a separate property assessment.

How long does air conditioning installation take?

A straightforward single-room installation can often be completed within a working day. Multi-split, ducted, difficult-access or electrical-upgrade projects can take longer.

Do I need an outdoor unit?

Conventional fixed split air conditioning uses an outdoor unit. Some specialist products use different arrangements, but they have different performance and installation trade-offs. The outdoor position should be considered early in the design.

Do London flats need permission for air conditioning?

Permission may be required. Flats do not benefit from ordinary householder permitted-development rights in the same way as houses, and leasehold or freeholder consent can be separate from planning permission. Check the specific building before work starts.

How much does air conditioning installation cost in London?

The installed price depends on system type, number of rooms, capacity, pipe route, electrical work, condensate drainage, outdoor-unit access and the building itself. A property-specific quotation is more useful than a generic fixed price.

Get an air conditioning installation quote in London

For air conditioning installation London homeowners can request a quotation based on the rooms, system type and proposed outdoor-unit position. Start with the rooms you want to cool, how the property is used and where an outdoor unit could realistically be installed. From there, the system can be designed around capacity, appearance, noise, controls and future servicing.