With UK summers becoming increasingly hotter, many of us find that go-to solutions like using fans and keeping curtains shut just aren’t cutting it anymore. As a result, many homeowners are considering air conditioning as an effective solution to keep them cool.
But with so many types of air conditioners on the market - each with different costs, space, and installation requirements - it can be difficult to know where to begin. How do you find the best solution for your budget and needs?
Look no further than our ultimate guide to choosing an air conditioner for your home! In this guide, we break down the types of air conditioners available for domestic use; compare them on key features like cost, installation, and energy efficiency; and answer your burning (or cooling) air-con questions!
Ready to become an AC expert? Keep reading to discover:
Types of air conditioners explained
How to choose the right air conditioner for your home
Find an air conditioning expert with JustFix
Do I need an air conditioner?
Air conditioners can be a worthwhile investment for many homes. However, most air conditioning units aren’t cheap. Before you purchase one, it’s worth considering if air con is the best way to cool your home.
Air conditioning can be a great solution if:
- You often feel uncomfortably hot in your home in the summer
- You’ve tried other solutions (like fans and keeping curtains shut), and your home is still too warm
- You struggle to sleep when temperatures are high
- Your home is humid, leading to other problems like damp and mould
If you’re unsure about committing to a permanent installation, you could start with a portable unit and upgrade to a built-in air conditioning unit if you’re still struggling with temperature regulation.
Types of air conditioners explained
There are five main types of air conditioning systems found in UK homes. Here’s a quick summary of each:
- Split-system air conditioning: A popular and energy-efficient option consisting of an indoor and outdoor unit, ideal for cooling a single room or open-plan space.
- Window air conditioning units are self-contained: Compact, self-contained units that fit into a window or wall opening. They’re budget-friendly and effective for single rooms but less efficient than split systems.
- Multi-split air conditioning: Similar to a split system, but allows multiple indoor units to connect to one outdoor unit, making it a great space-saving solution for cooling several rooms.
- Portable air conditioners: Standalone units that can be moved between rooms. They’re an affordable choice but generally less powerful than built-in systems.
- Central air conditioning: A ducted system designed to cool an entire home or building. While it’s the most expensive option, it offers excellent temperature control and efficiency.
Despite their differences in design and function, all air conditioners work on the same basic principle. They all use refrigerant to extract heat and humidity from the air and replace it with cool, fresh air. For a deeper dive into how AC units function, read our guide: How does air conditioning work?
Nonetheless, these units vary in supply and installation costs, running costs, and energy efficiency. They also require different amounts of space, and some can be noisier than others.
Not sure which system is best for your space? Keep reading to discover the factors you should consider before investing in an air conditioner. Or, find and book a qualified AC or HVAC installer to assess your property today.
How to choose the right air conditioner for your home
When deciding on the best air conditioner for your home, it’s important to consider a variety of factors. While cost is most people’s main priority, the size of the unit, its energy efficiency, and how noisy it’ll be are also essential considerations.
Supply cost
The cost of the air conditioning unit itself depends on the type, brand, and model you opt for. Here’s a price breakdown of the types of air conditioning:
- Portable air conditioners: £100 - £200
- Window air conditioners: £150 - £800
- Split-system air conditioning: £800 - £2,500 per room
- Multi-split air conditioning: £3,000 - £6,500 (depending on the property size)
- Central (ducted) air conditioning: £2,500 (for a single room) - £14,500 (for a whole house)
These prices reflect the cost of the unit alone, excluding the associated installation costs.
Installation cost
Installation costs vary depending on the type of unit you choose and the complexity of the work required.
Portable units incur no installation cost: simply plug the air conditioner in and turn it on.
Split-system units, including multi-split units, can cost between £1,000 and £2,000 depending on factors like wall access and pipework.
Window air conditioners are usually cheaper to install, starting at about £100-£200 and generally costing no more than £800.
A central ducted system is significantly more expensive to install and requires extensive work throughout the home. It’s typically only cost-effective for large homes, new builds, or commercial properties. You could expect to pay around £2,500-£4,000 per room for installation.
Following supply and installation, you’ll also need to consider the costs associated with using and maintaining your air conditioning unit.
Running and maintenance costs
Investing in an air conditioner isn’t just about the upfront cost; it’s also important to think about the bills you’ll pay to use it and how much it costs to maintain it. Based on recent energy prices in the UK (rates of around £0.24-£0.27 per kWh), here are the average running costs* for each type of AC unit:
- Portable air conditioners: £0.24p per hour
- Window air conditioners: £0.06-£0.19 per hour
- Split-system air conditioning: £0.16 per hour
- Multi-split air conditioning: £0.05-£0.25 per hour
- Central (ducted) air conditioning: £1.22 per hour
While these figures provide some guidance,the actual, accurate running cost of running air conditioning in the UK depends on variables like the unit's wattage, age, and efficiency.
Maintenance costs are another factor to consider. Any type of built-in domestic air conditioner will require annual servicing, which usually costs between £70 - £120 . This includes the labour and call-out fees, and you might incur additional fees for cleaning, repairs, or replacements.
*These running cost estimates are based on UK energy prices as of February 2025 (£0.24-£0.27 per kWh). Actual costs may vary depending on fluctuations in energy prices, the efficiency and age of your air conditioning unit, and how often it is used. For the most up-to-date electricity rates, check with your energy provider.
Energy efficiency
Energy efficiency refers to how much energy is used to achieve the desired temperature. A more efficient air conditioner will use less energy to cool your space, meaning you’ll benefit from lower electricity bills.
When choosing an air conditioning unit, opt for models with a high-energy efficiency rating (A+++ is the most efficient and G is the least efficient). Although an A+++ model is likely to cost more upfront, it often leads to savings on energy bills.
What s BTU?
British Thermal Units (BTU) measure an air conditioner's cooling capacity. The higher the BTU rating, the more powerful the air conditioner.
Choosing an air conditioner with the correct BTU rating for your space ensures optimal performance, efficient energy use, and long-term savings on electricity bills. A suitable unit will cool the room effectively, maintain a consistent temperature, and operate without unnecessary energy consumption.
What BTU rating do I need?
As a rule of thumb, allow 20 BTUs per square foot of space. Typically, a small room of up to 215ft² will best suit an air conditioning unit with a BTU rating between 5,000 and 8,000. Meanwhile, a larger room over 325ft² might require a 12,000+ BTU unit.
However, factors like ceiling height, sun exposure, and insulation can affect the BTU rating required, so consult an AC/HVAC technician for an accurate recommendation.
Size and space
The space available inside and outside of your property and the size of the air conditioning unit should also be taken into account.
If you have a smaller home or flat, or you’re renting, a portable unit will usually be the best option. They don’t take up too much space and won’t require modifications.
A split-system air conditioner comprises a wall-mounted indoor unit and an outdoor unit on your exterior wall. A multi-split system connects several indoor units to one outdoor unit, so it’s more space-efficient if you want to cool multiple rooms.
A window-mounted air conditioner sits in a window, so it doesn’t take up too much space. However, if you have limited natural light or small windows, it might not be the best choice.
A central air conditioner consists of an outdoor unit and interior vents (in the ceiling or walls) connected to ducts that run invisibly through your home. Due to the extensive ductwork required, this type of air conditioner is primarily suited to new builds, large homes, and commercial properties.
Brand and model
When choosing an air conditioning unit, always buy from a reputable retailer to avoid scams or faulty products. Trusted brands like Samsung, Bosch, LG, Daikin, and Mitsubishi produce energy-efficient and durable units.
Make sure you choose an up-to-date model from your brand of choice. Older models may be less efficient and more likely to break down.
Noise levels
Some air conditioning systems are noisier than others, so pay attention to the decibel rating of the unit.
Portable air conditioners are typically louder, so if you’re a light sleeper or sensitive to noise, they may cause a disturbance. Wall- and window-mounted split units are usually quieter, making them better for bedrooms and living areas. Meanwhile, ducted systems are the quietest, producing virtually no noise inside the property.
Find an air conditioning expert with JustFix
An air conditioner can be an excellent investment for many households. However, as with any home renovation project, it can be difficult to know where to start and who to turn to.
JustFix is here to help lighten that load by taking the stress out of finding quality tradespeople you can trust. Our network of pre-vetted professional electricians can help you choose the right air conditioner for your home, install it correctly, and oversee routine maintenance and servicing.
Here’s how it works: Download the app or use our website to book a service, whether you’re after a consultation, installation, or repair job. Tell us a time and date that works for you, and we’ll match you up with an expert in your area.
We’ll always quote you a fixed price for the work and promise a 12-month guarantee on any job. Book a service today and discover how our electricians can transform your home’s climate.
FAQs
Do you need planning permission to install an air conditioner?
You usually won’t need planning permission to install air conditioning. Permitted development rights cover most small air conditioning systems. However, you might need planning permission for an extensive central system bigger than 0.6m³, for example.
Furthermore, if you live in a restricted area or a listed building, you’ll probably need to seek planning permission first. More information is available on the home improvement section of the Planning Portal website.
Any electrical work undertaken in your home must comply with the relevant British electrical safety standards. As a result, we always recommend hiring a qualified electrician or air conditioning specialist to ensure your installation is fully compliant.
Is air conditioning bad for you?
Air conditioning reduces moisture and humidity in the air. As a result, spending a long time in an air-conditioned room can dry out your skin and eyes. Furthermore, if you have respiratory issues like asthma or allergies, air conditioning can aggravate them.
Although spending prolonged periods of time in an air-conditioned room (while you sleep, for example) can cause irritation, there are no serious illnesses associated with air conditioning.
How do you install portable air conditioning?
Portable air conditioning units don’t require professional installation. Simply choose an appropriate location (near a window), plug the unit in, and attach the exhaust hose to the window kit. For an accurate guide, read the instructions provided with your model.
Does air conditioning need PAT testing?
Portable air conditioning units should be PAT (Portable Appliance Testing) tested if they are in a workplace. There’s no legal requirement for PAT testing in domestic homes, but landlords do have a duty to maintain electrical appliances in a safe condition.
For built-in air conditioning systems, such as split or ducted units, PAT testing isn’t necessary as they are fixed installations rather than portable appliances. However, they should be inspected and maintained by a qualified electrician or HVAC technician during an annual service.
