Garden Room Air Conditioning: An Expert’s Guide

More people are starting to use air conditioners in their garden rooms. It’s easy to see the appeal. Everyone needs a way to keep their garden room cool in hot weather. Plus, modern air conditioners are multifunctional. They can also heat and dehumidify a room.

There are many good reasons to consider garden room air conditioning. You just need to choose the right air conditioner. Keep reading to learn everything you need to know about garden room air conditioning. This will include:

  • Factors to consider when choosing an air conditioner for a garden room
  • Types of air conditioners that are ideal for garden rooms
  • The installation and running cost of garden room air conditioning
  • How to maintain garden room air conditioning
  • Whether garden room air conditioning is worth it

Let’s get started.

Why should you install air conditioning in your garden room?

Consider garden room air conditioning for the same reason you would consider using an air conditioner in any other room. An air conditioner is very effective and efficient for keeping a room cool in summer. This is invaluable because British summers seem to be getting hotter and hotter.

Most garden rooms have insulation and thermal cladding. However, these two are not enough to keep heat out (and cool garden rooms in) hot summers. You still need an additional measure. Air conditioners are more than capable of being that extra measure.

Heating is another good reason to consider garden room air conditioning. Modern air conditioners are more than capable of being a garden room's primary heating system.

Garden rooms are relatively small. So, an air conditioner can easily provide enough heating coverage. Besides, air conditioners are more energy efficient than some popular garden room heating systems. At the very least, an air conditioning unit can be a secondary heating system for any garden room.

You should also consider garden office air conditioning because of dehumidification. Some air conditioners have a dehumidifier mode that is useful during winter. Air conditioners that can also heat and dehumidify are usually more expensive. However, they are worth investing in.

Why should you install air conditioning in your garden room?

Choosing the right air conditioning system for your garden room

Here are a couple of factors to consider when selecting garden room air conditioning.

Room Size

Obviously, you want an air conditioner that is powerful enough to cool your garden room. You don’t want an air conditioner that is not powerful enough or too powerful.

If an air conditioner is not powerful enough, it won’t be able to cool the garden room. It will have to work too hard, affecting its durability. On the other hand, an overpowered AC will be a waste of money. You’d be spending more money than necessary on installation and running costs. An overpowered air conditioner will also have to start and stop more often, affecting its durability.

Here is a simple way to calculate the air conditioner size for a garden room. Multiply the square footage of the garden room by 25. That’s the capacity of the air conditioner needed for that garden room. This value is measured in BTU (British Thermal Unit).

Energy Efficiency

You also don’t want a garden room air conditioning unit that will drive up your energy bills. So, consider energy efficiency. Fortunately, modern air conditioners are very energy efficient. Still, you should compare energy efficiency between models and brands before buying. It’s good for your wallet. It’s also good for the environment.


Most garden room is insulated. Insulation and thermal cladding are two of the basic features of garden rooms. However, insulation methods and materials are not equal. Some are better than others.

Also, some garden rooms might not be adequately insulated. For example, there might be spaces between doors and windows for heat to pass through. The roof and flooring may also be poorly insulated.

All these affect heat exchange between the garden room and its environment. It also affects the capacity of the garden room air conditioning unit that’s required. For example, a well-insulated garden room can make do with a smaller air conditioner. Meanwhile, a poorly installed one can’t.

Content of the garden room

Let’s use garden office air conditioning to explain this factor. An office has machines like computers, printers, scanners etc. These machines produce heat. Therefore, you’ll need a more powerful air conditioning unit.

This same logic applies to the number of occupants inside the garden room. The human body gives off heat. So, consider the number of people usually inside the garden room. If there are more people, you need a garden room air conditioning that has a higher capacity.

Your budget

Budget is also important. Garden room air conditioning costs between £200 and £2,000 depending on the type and size of the air conditioner. However, this is just the installation cost.

You also have to consider running costs. This also depends on the type and size of the AC, alongside other factors. However, it usually costs around 10 to 25 pence per hour to run garden room air conditioners.

Personal preference

Some people prefer portable air conditioners. Others prefer permanent units like split systems. Both have their pros and cons. They also vary in price and capacity, with split system air conditioners being more expensive and higher capacity. Both portable and split air conditions are excellent for garden room air conditioning. So, let’s look at the features, benefits and cons.

Types of Garden Room Air Conditioning Systems

Most garden room air conditioning units are either portable or split systems. Let’s talk about them.

Split System Air Conditioners

A split system comprises two units: a fan and a compressor. The fan is installed inside the room while the compressor is outdoors. Both units are connected by a copper tube.

Split system air conditioners are mounted to a wall. They need to be installed by an F-Gas engineer, adding more to the installation cost. Split system air conditioning costs around £500 to £2,500.

However, they have better cooling capacity, energy efficiency, and noise levels. Better cooling means you can cool a larger space. Better energy efficiency means a lower running cost, a valuable long-term benefit. Finally, there is their lower noise level. Who doesn’t like a quiet air conditioner?

Split System Air Conditioners

Portable Air Conditioners

Portable air conditioners are also great for garden rooms. They are more affordable than split systems. Portable garden office air conditioning costs just £200 to £400.

You also don’t need a professional installer. Just place the portable air conditioners anywhere, then lead the exhaust pipe outdoors. Because they are portable, you can relocate this air conditioner at will. You can even shuffle it between the garden room and the main house.

However, this does mean that portable air conditioners take up floor space. Spilt systems are mounted on walls. Therefore, they don’t take up precious floor space.

Portable air conditioners also have lower heating capacity. In fact, you should only use them for spaces that aren’t bigger than 20 square metres. Finally, portable air conditioners are also noisier than split systems.

Portable Air Conditioners

The costs of garden room air conditioning

Let’s discuss how much it costs to install or run garden room air conditioning.

How much does it cost to install air conditioning in a garden room?

Installing garden room air conditioning costs £200 to £2000, depending on the type and size. We just talked about the types of air conditioners commonly used in garden rooms. The main ones are split systems (£500 to £2,500) and portable ACs (£200 to £400).

As for size, that’s easy to understand. A bigger air conditioning unit will cost more. However, this doesn’t mean you should get the smallest available air conditioner. Garden rooms are relatively small. So you don’t need a high-capacity air conditioner. You just need an air conditioner with the right BTU (aka capacity).    

How much does it cost to run an air conditioner in a garden room?

The running cost of garden room air conditioning is usually around 10-25 pence per hour. However, this will depend on factors like the air conditioner’s power consumption rating and your electricity rate.  You can find the former on the air conditioner’s manual and the latter on your utility bill.

Multiply the air conditioner’s power consumption rating by your electricity rate. That’s how much it costs to run that garden room air conditioning unit. Here is an example.

Let’s assume the air conditioner’s power consumption rate is 0.5 kW and your electricity rate is 24.50 pence per hour. Running that garden room air conditioning unit will cost 12.25P per hour (0.5 ×24.50).

An air conditioner’s power consumption rating will vary depending on its function. For example, it might consume more energy when heating (a room) than when cooling (it).  

How to maintain and care for a garden room air conditioning unit

There are a few things you can do to ensure the longevity and optimal performance of a garden room's air conditioner. Here they are.

Regular Cleaning

Essentially, you need to clean the coil, filter and vent of your garden room’s air conditioner. An air conditioner needs coils to transfer heat, a filter to remove dist and debris, and vents to circulate air. Problems with any of these affect the air conditioner’s performance and air quality.

Such problems usually occur because of the buildup of debris and dirt. They accumulate over time until the filer, vent and coil get clogged. Remove those buildups regularly. Clean the coil, filter and vent of your garden rooms or conditioning regularly.

For split air conditioning systems, you should also clear the area around the compressor. Remove loads, debris, and other items around the unit. Give the compressor at least 24 inches of clearance space on all sides.

Thirdly, close doors and windows when using air conditioning. If you don’t, the garden room won’t be adequately insulated. As a result, the air conditioner will have to overwork itself to keep the room cool. This is not energy efficient. It also affects the air conditioner’s longevity.

Regular Cleaning

Professional Servicing

Aside from regular cleaning, a garden room air conditioner also needs annual professional services. You can do this alongside other air conditioning units in your home.

Hire a trained professional to inspect the air conditioner, fix what needs fixing, and ensure everything works correctly. You should also call the professionals when you notice issues. Don’t wait until the problem gets worse. Call a qualified F-Gas engineer if you notice strange sounds or poor performance.

Professional Servicing


An air conditioner could be your one-stop tool for creating the desired environment in your garden room. Modern air conditioners don’t just cool a room. They provide general heat and moisture regulation. They can heat, cool and dehumidify. So, upon installing garden room air conditioning, you may no longer need a separate heater or dehumidifier. This might not be ideal for every scenario, but it’s still worth considering.

Whatever you decide to do, it’s crucial to pick the right air conditioner. As we discussed, this involves considering factors like room size, energy efficiency, insulation, content of the room, budget and personal preferences. You should also remember that both split systems and portable air conditioners have their strengths and weaknesses.

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