More than four million UK homes now have air conditioning, double the figure from three years ago, as temperatures hit 37°C in some regions. But before you buy, industry experts Ian Brown from British Gas and Will Jones from Currys advise asking these 13 critical questions.
Are air conditioning units necessary in the UK?
Ian Brown notes: "Air conditioning is becoming more popular in the UK as summers get warmer. While it's not essential for every home, it can help make your living space more comfortable by keeping rooms cool, reducing humidity and improving air circulation. Many modern systems can also provide heating during colder months, so they can be useful throughout the year."
Will Jones agrees: "Air conditioning was once seen as a luxury in the UK, but as heatwaves become more frequent and homes retain more heat, it's becoming an increasingly practical investment." Portable units are particularly popular because they don't require permanent installation and offer heating, dehumidifying, and fan functions year-round.
How much do they cost to buy?
According to Ian, upfront costs depend on the system type and home size: "Portable units are usually the cheapest option, while wall-mounted systems require installation but offer a more permanent solution." Will adds that portable air conditioners start from around £269 for entry-level models like the Logik LAC07C25, while premium smart models like the MeacoCool range cost up to around £529. Professionally installed wall-mounted systems from brands such as Toshiba typically start at around £2,500 and can exceed £3,200, including installation.
What are the different types?
Portable units can be moved from room to room and don't require installation. Wall-mounted split systems are permanently fixed and designed to cool or heat a room efficiently. Multi-room systems can control temperature in several rooms at once. Will explains: "Portable units are flexible, simple to set up and ideal for renters, flats or homes where permanent installation isn't practical. Fixed split systems provide more powerful, quieter cooling and often greater energy efficiency, but they require professional installation and a higher upfront investment."
How much do they cost to run?
Independent testing by Which? found the average portable air conditioner costs 22p per hour on its highest setting, with the cheapest at 17p and the priciest at 31p per hour. MoneySuperMarket data notes that running costs depend on efficiency rating, usage level, and electricity tariff. A modern A-rated split system costs between 10p and 50p per hour for cooling. Will calculates: a typical 1,200-watt portable unit running eight hours a day costs around £2.50 per day, adding £75 a month to your bill. Wall-mounted split systems cost between 20p and 54p per hour to run.
How effective are portable units?
Will says: "Portable air conditioners are very effective at cooling individual rooms when they're correctly matched to the size of the space. The key is choosing the right BTU rating. A unit that is too small will struggle to cool efficiently, while one that's oversized may cool the room quickly without removing enough humidity." Ian adds: "They're often popular with renters or people looking for a lower-cost way to stay comfortable. However, if you're looking for cheaper long-term running costs and heating, wall-mounted air conditioning is a no-brainer."
Choosing the right BTU rating for your space
Will advises matching capacity to room size: Up to 14m² (small bedrooms) look for a 7,000 BTU unit. Up to 20m² (standard bedrooms/small living room) look for a 9,000 BTU unit. 20m² and above (large living rooms) requires 12,000 BTU or more. He also recommends checking energy efficiency, noise levels, and features like dehumidifying, heating, timers, and smart controls.
Practically, what do portable ones need?
"They're straightforward to set up," Will confirms. "Simply plug the unit in, position the exhaust hose through an open window using the supplied window kit, and you're ready to go." In very humid conditions, some models may occasionally need the water tank emptied, although many modern units use self-evaporating technology, so manual draining is rarely required.
Are air-conditioning units noisy?
Ian notes: "Modern air conditioning systems are typically much quieter than many people expect. Most are designed to run quietly in the background." Portable air conditioners are louder because the compressor sits inside the room. Will adds: "Most operate between 50 and 65 decibels, similar to a normal conversation. If using one overnight, choose a model with a dedicated sleep or night mode."
Which is better, portable or wall-mounted?
Both experts agree it depends on needs. Ian says: "Portable units are more affordable upfront and can be moved around the home, while wall-mounted systems tend to be quieter, more efficient and better suited to people looking for a long-term heating and cooling solution." Will adds: "If you're looking for a long-term solution with quieter operation and stronger performance, a professionally installed wall-mounted system is likely the better option."
What should buyers look out for?
Will advises: "Room size should always be the starting point, followed by the correct BTU rating, energy efficiency and noise levels. Look for Energy Class A or A+ models, along with features such as eco mode, programmable timers, and sleep settings. Many models also double as dehumidifiers and fans, while some offer heating and smart app controls."
Best overall models to buy
Will recommends three standout models: Best overall is the MeacoCool MC12000RPRO Smart Air Conditioner & Dehumidifier for excellent cooling performance, relatively quiet operation and smart connectivity. Premium option is the De'Longhi Pinguino EX130CST Smart Air Conditioner & Dehumidifier offering powerful cooling and app control. Best multi-tasker is the Igenix IG9909WIFI 4-in-1 Portable Air Conditioner combining cooling, heating, fan and dehumidifier functions. British Gas recommends Bosch air conditioning units for their advanced technology, quiet performance and high quality.
Could air conditioning add value to a home?
Will says: "There's no guarantee that installing air conditioning will increase a property's value, but buyer expectations are changing as hotter summers become more common. Portable units offer a simple, non-permanent way to improve comfort, while professionally installed systems can make a home more appealing to buyers looking for year-round climate control."
Do I need planning permission?
In most cases, you do not need planning permission if your system meets all criteria: it must provide both heating and cooling (operating as an air source heat pump); the external compressor unit must not exceed 0.6 cubic metres; it cannot be installed on a pitched roof; if on a flat roof, it must be at least 1 metre from the roof edge; the external unit must be at least 1 metre from your property boundary; and it should not be placed on a wall or roof facing a public road. You will need planning permission if your property is a flat or apartment, a listed building, in a conservation area, or if you install multiple or oversized units. Commercial properties have different, generally more stringent rules.
