When you’ve made the wise decision to invest in air conditioning for your home or commercial premises, that’s actually only the beginning of the decision making process.

That’s because to get the most out of air conditioning, the location, both in terms of the choice of room and the positioning within the room matters.

Poorly positioned indoor units are notorious for cooling one corner of a room while leaving another uncomfortably warm. Likewise, a badly sited outdoor unit can overheat, lose efficiency or generate noise complaints from neighbours. Across the life of the system, these issues translate into higher energy bills, more frequent servicing and a shorter lifespan for the equipment.

As professional air conditioning installers here at Lee Jackson, helping our clients to determine the most advantageous installation locations for their air conditioning units is all part of out service.

Until you contact us about your project, these are our expert tips on ideal locations for your air conditioning unit, along with the key areas to avoid.

Residential Air Conditioning Installations

Residential installations typically involve wall-mounted split systems, with a single indoor head connected to one outdoor unit. Multi-split systems are increasingly common, where more than one room requires conditioning. The guidance below covers the most common room types found in UK homes.

Living Rooms And Open Plan Spaces

The living room is often the first room homeowners choose to air condition, particularly in open plan kitchen-diner layouts where heat from cooking compounds the challenge.

Best positions:

High on the wall opposite the main seating area, so cooled air travels across the room before reaching occupants
On the longest central wall in open plan spaces to maximise airflow reach across the full floor area
At least 15 to 20 centimetres below the ceiling so the unit can project air in a wide arc and mix it with ambient air at a comfortable level
Ceiling cassette units where a ceiling void exists, as these distribute air in four directions and suit larger or irregular room shapes particularly well

Positions to avoid:

Directly above fireplaces, wood burners or radiators, where rising heat will confuse the thermostat and cause unnecessary overcooling elsewhere in the room
On a south or west-facing wall where prolonged afternoon sun heats the wall surface and the air immediately around the unit
Above large pieces of furniture, such as sofas or shelving units that block the discharge of cooled air and trap it in a small area
Corner positions that force air along two walls rather than distributing it across the whole room

Bedrooms

Bedrooms present a particular challenge because comfort requirements during sleep differ from daytime use. Airflow direction, noise level and overnight temperature management all become more important.

Best positions:

High on the wall to the side of the bed, rather than directly above or opposite it, so airflow can be angled away from the sleeping area
On a north or east-facing wall where the wall itself is cooler and morning sun does not warm the area around the unit
Units with a sleep or quiet mode that reduces fan speed and airflow velocity during overnight operation should be prioritised for this room type

Positions to avoid:

Directly above the bed, where cooled air falls onto sleeping occupants, causing draughts and discomfort
Directly opposite the bed, where the unit blows air straight across the sleeping area
Above or adjacent to fitted wardrobes that restrict the return air path and reduce the unit’s ability to draw in warm room air efficiently
South-facing walls, where afternoon heat gain causes the thermostat to work harder than necessary

Home Offices

Home offices typically have a relatively small footprint but may carry a higher heat load than other domestic rooms due to computer equipment, monitors and ancillary devices. The combination of heating and cooling that an inverter split system provides makes it particularly well suited to this room type year-round.

Best positions:

On a central wall with a clear path to distribute air evenly across the workspace without creating cold spots at the desk
Positioned to allow the unit to serve as a heat pump in winter, providing both functions from a single installation
High enough to ensure airflow does not blow directly across desk surfaces, disturbing papers or creating localised draughts at head height

Positions to avoid:

Directly above computer equipment, monitors or server racks where condensate drip risk and thermal interference are genuine concerns
Adjacent to external walls carrying significant solar gain, which skews thermostat readings and forces the system to overwork
Positions where cable management becomes difficult and the pipework route to the outdoor unit requires excessive bends or a long run

Kitchens

Kitchens generate significant heat from cooking appliances and benefit considerably from air conditioning, but the environment presents challenges including grease, steam and high ambient temperatures that require careful positioning.

Best positions:

Higher on the wall than in other rooms to account for the additional heat load rising from cooking surfaces
On a wall that allows the unit to draw in cooler ambient air from the dining or living area, rather than recirculating kitchen air
Position that allows easy access to filters, which will require more frequent cleaning in a kitchen environment

Positions to avoid:

Directly above or adjacent to hobs, ovens or extraction units where grease, steam and heat will coat the indoor unit and reduce its lifespan rapidly
Positions where the airflow conflicts with the kitchen extraction system, creating competing pressure zones that reduce the effectiveness of both
Low on the wall where the unit draws in the warmest, grease-laden air from cooking at surface level

Conservatories & Garden Rooms

Conservatories and garden rooms are among the most challenging spaces to condition because of high solar gain through glazing, poor thermal mass and, in older properties, inadequate insulation. Air conditioning can make these spaces usable year-round, but positioning is critical.

Best positions:

On the solid wall that connects the conservatory to the main house, away from the glazed sections where solar heat is most intense
High on the wall to maximise air distribution across the full volume of the space
Systems with a high seasonal coefficient of performance (SCOP) are particularly beneficial here, given the extremes of temperature the space will experience

Positions to avoid:

On or adjacent to south or west-facing glazed walls, where the thermostat will consistently read a falsely high temperature due to solar radiation
In poorly insulated conservatories without addressing the building fabric first. Air conditioning will struggle to maintain a comfortable temperature and will run almost constantly at high cost
Outdoor unit positions that are hemmed in by garden furniture, dense planting or boundary fences that restrict the ventilation clearances the unit needs

Outdoor Unit Placement: Residential Properties

The outdoor unit is often treated as an afterthought, but its position is just as important as the indoor unit and comes with its own set of considerations that are particularly relevant in UK residential settings.

Best positions:

On a north or east-facing wall where the unit is shaded from the afternoon sun, which is most intense in the UK climate, as this can improve efficiency
Wall bracket mounting at first-floor level on smaller urban plots where ground space is limited and the unit is kept away from ground-level flooding risk
Ground mounting on stable, level concrete pads in larger gardens where access for maintenance is straightforward and there is no flooding risk
A position that keeps the unit within 10 to 15 metres of pipe run from the indoor unit, minimising refrigerant volume and installation complexity

Positions to avoid:

Directly beneath bedroom windows or adjacent to boundary fences where operational noise at 45 to 65 decibels will disturb sleep or neighbours
In enclosed side returns or tight alleyways where clearance on all sides is insufficient and the unit recirculates its own exhaust air
On or facing south-facing walls, where sustained afternoon sun significantly raises the ambient temperature the unit is working against
In low-lying positions in gardens with known surface water drainage issues or flood risk
On roofs in residential settings, which is not permitted under permitted development rules in England

Commercial Air Conditioning Installations

Commercial installations involve a wider range of system types, from individual wall-mounted split units in small offices through to multi-zone VRF systems serving entire buildings. The room-by-room considerations below apply across most commercial property types, with specific notes on sectors where specialist requirements apply.

Offices

Offices vary enormously from small cellular rooms to large open-plan floors and the right system and position depends heavily on the ceiling height, ceiling void availability and occupancy density.

Best positions:

Ceiling cassette units in open-plan offices where four-directional air distribution provides even coverage across the whole floor area without creating strong directional airflow over individual workstations
Concealed ducted systems behind suspended ceilings in higher-spec environments where aesthetics and acoustics matter
Wall-mounted units high on the end wall of cellular offices, angled to distribute air across the full room without blowing directly onto the desk nearest the unit
Dedicated precision cooling units in server rooms and IT comms rooms rather than standard comfort cooling systems, which are not designed for the heat densities involved

Positions to avoid:

Directly above individual workstations where cold air falls onto seated occupants and creates persistent complaints regardless of thermostat settings
Positions that place the indoor unit in conflict with existing mechanical ventilation, creating competing pressure zones that reduce the effectiveness of both systems
Shared systems for server rooms and office spaces, as the thermal load and temperature requirements of the two environments are fundamentally different

Retail Premises

Retail premises need to balance effective climate control with customer experience and operational practicality. Visible ductwork or poorly positioned units affect the perception of the space as much as the temperature itself.

Best positions:

Ceiling cassette or concealed ducted systems that preserve the aesthetic of the sales floor and avoid using wall space that might otherwise carry product displays or signage
Systems positioned to distribute conditioned air across the sales floor evenly before customers enter from the street entrance
Simpler wall-mounted units in back-of-house stockroom and staff areas where aesthetics are less important

Positions to avoid:

Discharge aimed directly at the entrance, where conditioned air is lost immediately to the outside every time the door opens
Positions directly above temperature-sensitive stock, such as food, flowers, cosmetics or electronics where localised cooling at the unit discharge point may affect product quality
Visible wall-mounted units in premium retail environments, where they conflict with brand aesthetics

Restaurants, Cafes and Hospitality Venues

Hospitality venues like restaurants and cafes carry high and variable heat loads driven by occupancy, kitchen output and the frequent opening of external doors. Front-of-house and back-of-house areas have very different requirements and should generally be served by separate systems.

Best positions:

Ceiling cassettes or concealed systems in dining areas that distribute air gently and evenly without creating localised draughts at table level
Separate, dedicated systems for kitchen areas designed to work alongside the extraction system rather than competing with it
Systems with humidity control capability in venues where food service or open kitchens create elevated moisture levels

Positions to avoid:

Discharge aimed directly over dining tables where customers will experience cold draughts and food will cool more rapidly than expected
Kitchen air conditioning that is positioned in a way which conflicts with the extraction system. Extraction removes air from the kitchen and any conditioning unit working in opposition will be largely ineffective
Single systems serving both kitchen and front-of-house areas, which cannot respond to the very different conditions in each zone simultaneously

Industrial Units & Warehouses

Large industrial spaces such as warehouses present unique challenges due to their volume, the heat generated by machinery and equipment and the frequent opening of large access doors that allow significant heat infiltration.

Best positions:

Multiple ceiling cassette or overhead ducted units positioned to create overlapping zones of conditioned air across the floor area
Zoning of loading bay and dock door areas separately from the main floor, as these areas experience the greatest temperature variation
Outdoor units on roof plant decks or dedicated ground-level plant areas with appropriate security fencing, drainage and maintenance access

Positions to avoid:

Single units attempting to condition a large volume, which will result in uneven temperatures and an overworked system
Positions that interfere with racking systems, overhead cranes, forklift routes or other operational equipment
Ground-level outdoor unit positions that are exposed to vehicle movements, forklift damage or surface water without adequate protection

Healthcare & Education

Air conditioning for healthcare and education settings carries specific regulatory and operational requirements that influence placement decisions beyond the standard engineering considerations.

Best positions:

In healthcare settings, systems that integrate with mechanical ventilation rather than recirculating room air between zones help maintain the infection control standards required by HTM (Health Technical Memoranda) guidance
In schools, low-noise units with sound power levels suitable for occupied classrooms should be specified. Units positioned on external walls away from teaching spaces minimise noise transmission
Ceiling cassettes or concealed systems in both sectors where aesthetics and the avoidance of wall-mounted units that pupils or patients might interfere with are important

Positions to avoid:

Systems that recirculate air between clinical zones in healthcare settings without appropriate filtration, which conflicts with infection control requirements
Loud outdoor units positioned adjacent to classrooms, consultation rooms or patient areas where operational noise causes disruption
Positions that make filter maintenance difficult in environments where hygiene standards require more frequent servicing than standard commercial premises

Hotels & Serviced Accommodation

Hotel air conditioning calls for a balance between individual room control, acoustic performance and the practicalities of running conditioning across dozens or hundreds of rooms simultaneously.

Best positions:

In-room fan coil units connected to a central VRF or chilled water system offer the best combination of individual room control and operational efficiency at scale
Units positioned high on the wall beside the entrance door rather than above the bed, allowing airflow to be directed across the room without disturbing sleeping guests
Outdoor condensing equipment on roof plant areas or dedicated ground-level plant rooms where noise, aesthetics and maintenance access can all be properly managed

Positions to avoid:

In-room units directly above the bed, which is the single most common source of guest complaints in hotel air conditioning installations
Shared systems between adjacent rooms where noise transmission through the building fabric from the unit or its pipework disturbs guests on either side
Ground-level outdoor equipment in visible guest arrival or garden areas where operational noise and aesthetics create a poor impression

Outdoor Unit Placement: Commercial Properties

Commercial outdoor unit placement differs from residential in scale, the likelihood of roof mounting and the greater scrutiny that planning authorities apply to commercial premises.

Best positions:

Roof plant decks with appropriate structural assessment, vibration isolation and acoustic treatment are the most common and practical solution for multi-unit commercial installations
Dedicated ground-level plant areas with security fencing, hard standing, drainage channels and maintenance access for smaller commercial premises
Positions that meet the minimum clearance requirements specified by the manufacturer and allow unobstructed airflow on all sides of each unit

Positions to avoid:

Positions adjacent to noise-sensitive receptors such as residential properties, schools or hospitals without a BS 4142 noise assessment confirming compliance
Roof positions without a structural survey confirming the roof can bear the combined load of multiple units plus maintenance access requirements
Ground positions exposed to vehicle movements, flooding risk or security vulnerabilities without appropriate mitigation

The Top Problems You Can Avoid By Choosing The Right Air Conditioning Placement

Poor cooling performance – Incorrect unit sizing or placement can leave rooms too warm even when the system is running.

Higher energy bills – Inefficient installation makes the system work harder than necessary, increasing electricity costs.

Uneven room temperatures – Bad positioning or airflow design can cause hot and cold spots around the property.

Excessive noise – Poor mounting or incorrect placement of indoor/outdoor units can lead to vibration and loud operation.

Water leaks and condensation issues – Incorrect drainage setup can cause water damage to walls, ceilings or floors.

Reduced system lifespan – Improper installation puts extra strain on components, causing earlier breakdowns.

Poor indoor air quality – Bad airflow design or incorrect filter placement can allow dust and allergens to circulate.

Electrical safety risks – Faulty wiring or non-compliant installation can create safety hazards.

Warranty invalidation – Many manufacturers require professional installation for warranties to remain valid.

Planning or compliance issues – Incorrect placement of outdoor units may breach UK planning rules or building regulations.

Refrigerant leaks – Poor pipe connections can lead to gas leaks, reducing efficiency and requiring costly repairs.

P.S. Are you experiencing any of the above issues with your current domestic or commercial installation? Contact us today to get a free quote for air conditioning repairs or replacement.

Want Expert Advice About The Best Place To Install Air Conditioning In Your Home Or Business?

Lee Jackson specialises in domestic and commercial air conditioning. So, if you’re in the market for air conditioning, it pays to get expert advice to choose the best installation location and placement within your property.

We operate across the East Midlands area of the UK, including the surrounding areas of Derby, Nottingham and Leicester.

Let us know how we can help by giving us a call on 0800 949 9070.

Or, please send us a message, and our team will be in touch shortly.