Best Portable Air Conditioners (top UK aircon units reviewed)

When temperatures soar during the few weeks that we call Summer here in the UK, things can get a bit uncomfortable. Especially if you work from home and your house is a sun trap.

Last Summer the temperature in some parts of the UK peaked at 40 C which led to many of us running our bladeless fans almost continuously. And while a decent electric fan will help to cool you down by evaporation, it does absolutely nothing to lower the temperature of the room.

Which is why so many UK households opted for a portable aircon unit last Summer. Obviously air conditioning is the only reliable way of cooling your home down during a serious heatwave. But a full on central air conditioner is expensive to buy and install and hardly seems worthwhile when we’re only likely to get around four weeks of very hot conditions.

This makes a portable air conditioner the perfect solution because they are relatively affordable, easy to move from room to room and surprisingly not too expensive to run.

Top Portable Aircons UK

Here’s our picks for the best air conditioners you can buy in the UK:

How Does A Portable Aircon Unit Work?

Portable A/Cs work using the laws of thermodynamics which state that the temperature will always try to equalise. In other words, hot air in a cold environment will try to cool and cold air in a hot environment will try to become hotter.

Lifting The Lid On Portable A/Cs

Inside the portable aircon unit you will find two radiators, one becomes cold and the other gets hot. The cold radiator absorbs heat from the room whilst the hot radiator expels heat from the room via the exhaust hose.

Running through both radiators on a continual loop is a copper pipe filled with a refrigerant. The system operates like this;

1. The cold refrigerant takes in the heat from the room which makes the refrigerant become hotter. 
2. It then passes through the compressor and heats up further as it gets pressurised by the compressor.
3. Once it reaches the condenser, the heat gets expelled to the outside (via an exhaust hose) which lowers the temperature of the refrigerant.
4. Which turns it back into a cooler liquid.
5. As it goes through the expansion valve, the refrigerant turns back into a gas at an extremely low temperature.
6. The process is then repeated continuously.

Advantages Of A Portable Air Conditioner

Let’s take a look at the positive reasons for buying a portable air conditioner unit. These include;

• Easy To Move From Room To Room
  Many portable aircon units are on wheels which makes them even easier to move around your home to the room that needs cooling.
• Saves Energy Costs
  A central aircon system will cool the whole house, including unused and unoccupied rooms. A portable aircon unit will only cool the room you’re in thus saving energy and costing less to run.
• Easy To Install
  A central air conditioner will need to be installed by a professional whereas, all that is needed with a portable A/C is a window and a plug socket.
• Dehumidifies As It Cools
  A portable aircon unit will dry the air as it cools it down. This removes that sticky, sweaty feeling caused by high humidity.
• Can Be Stored Away When Not In Use
  With a central A/C or a permanently installed window A/C, it is always there on view in Summer and Winter. A portable A/C can be stored away out of sight during the majority of the year when temperatures don’t justify turning on any form of air conditioning.
• More Affordable
  Many modern portable aircon units are smaller and far less expensive than earlier models used to be. This means a portable air conditioner is readily available to more people.

Disadvantages Of A Portable Air Conditioner

As can be seen above there are many advantages to owning a portable aircon. However, there are a few negatives as well which include;

• They’re Noisy
  There’s no escaping the fact that portable A/Cs are noisy. If you’re someone that is easily annoyed by a constant noise, you might want to rethink the whole portable aircon idea. With that said many of the modern units are no louder than an electric fan on full power.
• They Cost More To Run
  Compared to a central A/C, a portable aircon unit will cost more to run because they have no proper outside exhaust apart from that hose. This means there is always a small percentage of warm air that recirculates along with the cold air which does slow down the cooling process. This means the A/C will need to operate for longer periods to cool the room to your desired level.
• Struggle To Cool Large Spaces
  This is by far the main drawback to owning a portable aircon unit. If you try to run it in a room that is too large for the unit you have bought, it might never cool that room sufficiently. You need to buy the correct model for the size of the room you intend to cool (more on this below).
• Window Kits Are Often Poorly Fitting
  To effectively cool your room, the exhaust hose needs to be placed through an open window to allow the heat to leave the room. To prevent that hot air from re-entering the room you will need a window kit. These kits often create poor seals which then allow heat back into the room.
• The Filters Can Become Clogged
  As the portable aircon unit relies on airflow to remove heat and produce cold air, the filters need to be checked and cleaned regularly. If not they can become clogged which will affect the efficiency of the unit.
• Water Reservoir Needs Emptying Regularly
  Some portable aircons have tanks to store the water produced during the cooling process. These tanks or reservoirs will need emptying to avoid them overflowing and ruining your carpet. Many of the more modern units no longer have water reservoirs but you’ll need to check.

Air Conditioner Buyers Guide

Before you purchase a portable aircon unit, there are a few things to consider. Which are;

Cooling Power (BTU Rating)

You’ll need to know the size of the rooms that you’ll be using your portable aircon in. This is because portable aircons come with different cooling powers. 

These will be quoted on the specs as BTUs (British Thermal Units) and the size of the room you intend to use the A/C in will dictate which cooling power you need.

How To Calculate How Many BTUs Your Portable Aircon Unit Needs To Have

To easily calculate how many BTUs your portable air conditioner will need for any room in your house just use the following calculation.

Measure the room in feet and then multiply by five for example a 16ft x 12ft room which is 7ft high will need a portable aircon unit with a BTU rating of 6720 or more to work efficiently.

We came to this figure because 16^ft x 12^ft x 7^ft x 5 = 6720 BTUs. This calculation will work for any room of any measurement.

Sometimes You Need To Add To The Room Size Figure

There are circumstances that mean you’d need to add to the BTUs required. These circumstances include;

• Rooms With Exceptionally High Ceilings
• Rooms Which Contain Lots Of People
• Rooms In Close Proximity To Kitchens
• Rooms That Are Sun Traps

If any of the above apply, it is worth sizing up on the BTU count when buying a portable air conditioner.

Positioning

This is important because there are two requirements that will need to be met here. Which are the position of a window and the position of a plug socket. 

Hose Length

The thing is you should never mess with the size of the exhaust hose on a portable aircon unit. They are designed to work at their most efficient with the exhaust hose that comes supplied with the unit. 

Power Cable Length

The other thing that’s not advisable is plugging your portable A/C unit into an extension cable.

It should be plugged directly into a wall socket which means you’ll need to have a window near to an accessible plug socket to run your portable A/C unit correctly and safely.

Easy To Operate

On the whole, portable aircons are pretty simple to operate, but it makes sense to check. Look at the controls, do they look easy to use? Will all of the family be able to understand them?

Maintenance

Then there’s the maintenance aspect to consider, how difficult will it be to clean the filters and/or empty the water reservoir (if applicable).

Capacity Of Water Reservoir

Obviously if your A/C unit has a small water tank, it will require emptying on a more frequent basis than a unit with a larger capacity reservoir.

Weight

One of the main selling points for portable aircons is that they’re portable. But some are far heavier than others, this means that some portable A/Cs are less portable than others.

Consider where you’re most likely to want to operate your aircon unit. Does it involve carrying it upstairs? In which case, the lighter the better.

Noise Level

All portable air conditioners are noisy when running, but some are way louder than others. While the majority run anywhere between 50 to 60 decibels which is probably acceptable for sleeping, there are others that are more like 70 to 80 decibels which would definitely infringe on your peace and quiet.

60 decibels is about the same level as a normal conversation or a standard  electric fan. 80 decibels is more like the level of an argument or shouting.

Type Of A/C

There are really two different types of portable aircon units available or three if you include evaporative coolers. The main two are;

1. Single Hose
   These are the most common portable aircon units and they work by drawing air from the room, cooling it as mentioned above and then expelling the hot air through the exhaust hose. Whilst also drawing in air from the room to cool the components down. This creates a negative pressure in the room. Which means that air will try to enter the room by any available means like door cracks, gaps in the window kit etc. All of which makes the A/C unit have to work harder to remove heat.
2. Dual Hose
   Dual hose portable A/Cs work differently and are more energy efficient. There are two hoses which are both connected to the window kit. One works as an exhaust hose exactly like on the single hose models. The other hose takes air into the A/C unit to cool down the internal components which maintains an equal air pressure (no negative air pressure, so no extra warm air trying to enter the room). Dual hose units tend to be able to cool larger rooms, have better energy efficiency ratings but also cost more than single hose models.
3. Evaporative Coolers
   These are not technically air conditioners but we’ll include them because they are portable and they can cool the area around them. They have no hoses and the only internal part is a fan. They are typically designed with a tray of cold water (some use ice) which is blown via the fan and this cool damp air can cool the temperature slightly in front of the cooler. They work on the principle of evaporation and as we said earlier, they’re not really air conditioners. The one good thing about evaporative coolers is that because they have no exhaust hose, they are not restricted by needing to be close to a window.

Style

There are so many portable aircons available on the market currently which gives you far more choice when it comes to aesthetics. Some are very boxy whilst others are sleek and stylish. 

Ultimately it is an appliance for cooling you down in extreme heat conditions. So style might not be so high up on your list of considerations. 

However there are some people who believe that style is everything.

Size

The actual dimensions of portable air conditioners can vary considerably. Which means some are big and bulky while others are far more compact.

You will need to consider the space that you have available in your room and whether the unit you choose will fit.

Remote Control

Some models come with a remote controller which allows you the luxury of controlling the aircon from the comfort of your favourite armchair.

If this is a feature you would like you’ll need to check the unit you choose comes with a remote controller.

Dehumidifier

Some models can be used as dehumidifiers as well as aircon units. This feature can be very useful in hot, humid conditions to dry the air as it cools.

HEPA Filters

Many portable A/Cs are now fitted with High Efficiency Particulate Absorbing filters. These are designed to remove minute particles of dust, pollen, mould spores etc from the air to improve its quality.

Fan

There are some A/Cs that have a fan mode as well. This can be good for directing the cool air just where you want it.

Window Kit

Some portable air conditioner units include a window kit in the price. If they don’t you will almost certainly need to buy one separately. 

Unfortunately these window kits often prove to be insufficient when it comes to sealing the window correctly. You can make your own out of plywood or polystyrene and strong tape.

Energy Efficiency

As with all electrical appliances, portable air conditioners do have an impact on the environment. You can do your bit to cut down on environmental damage by choosing an energy efficient model.

Energy ratings run from A to G with A being the most energy efficient. You should also look for an A/C that doesn’t use the harmful chlorofluorocarbons (CFCs). 

Better alternatives are R410A, R32 and R290 refrigerants. However as R290 is highly flammable you would be better off with a portable air conditioner that uses R410A as a refrigerant as it has a low flammability level.

Timer Switches

Most portable air conditioners feature a timer mode or sleep mode or on some it’s called “eco mode”.

Smartphone Connectivity

Many portable air conditioners can link to your smartphone via an app and can also link to your voice assistant to allow you more control of the temperature of the room.

Running Cost

With energy prices on the rise here in the UK, the cost of running your portable A/C unit could be your main consideration.  As with any electrical appliance, the amount of energy it uses depends on the size of the motor. Or how many watts the unit uses to operate.

With aircon units the higher the BTU rating often equates to a higher wattage too. At current average costs of 34p per unit, the average cost of running a portable air conditioning unit will be;

• 34p per hour for a 1000 watt model
• 41p per hour for a 1200 watt model
• 51p per hour for a 1500 watt model
• 68p per hour for a 2000 watt model
• 85p per hour for a 2500 watt model

How To Calculate The Running Cost Of A Portable Air Conditioner

To calculate the cost of running a portable air conditioner you need to divide the number of watts by 1000 then multiply by the cost of a unit of electricity this gives you the cost per hour. 

So A 2000 watt portable A/C unit powered by electricity at 34p per unit will cost 68p per hour because 

2000 ÷ 1000 = 2 x .34 = .68p

LED Display

LED display screens can make it easier to see exactly what’s going on. If you prefer LED screens, look for a portable aircon with a LED screen display.

Price

Portable air conditioners start at around the £300 mark for anything halfway decent and can cost upwards of £1000. If you see any that are below the £300 price range they’re usually evaporative coolers rather than true portable air conditioners.

How much you will need to spend on a portable A/C will very much be dependent on how many BTUs the unit has and this will depend on the size of your room.

Warranty

Many aircon units carry a two year warranty but you need to check as there are many of the cheaper models that only have 12 month warranties.

However, any warranty is only as good as the company that issued it. We always recommend buying a well known brand from a reputable seller.

Frequently Asked Questions