Pinguino PAC N90ECO Silent
The best air conditioners will cool your room quickly and evenly. The worst will be slow to cool your room, make a racket and be such a hassle to set up that they leave you hot and bothered.
For many people, an electric fan will be a better option than air conditioning. If you already know that you want an air conditioner, but you're puzzled by words like 'portable', 'standalone', 'BTU' and 'refrigerant', read on to find out all you need to know before buying.
There are two main types of domestic air conditioner:
Portable air conditioners are also known as single-unit air conditioners, standalone air conditioners and mono block air conditioners. You plug these into a mains power socket and dangle the hose out of a window or door, as pictured above.
Split-unit air conditioners are also called fixed air conditioners. These have an indoor and outdoor unit – the indoor unit is fixed to inside of an exterior wall, and the outdoor unit is fixed on the other side of the wall or installed on the ground outside.
Air conditioners come in various shapes and sizes, but are often described in terms of their BTU (British thermal unit) output. In theory, the higher the BTU claimed, the more efficiently it can cool a room.
As a general rule, 5,000 to 8,000 BTUs is adequate for most living rooms or bedrooms. There's a calculation you can use to work out what BTU is right for you. As a very rough guide, multiply the dimensions (in feet) of the room by five.
So for a room measuring 15x10x8 feet: 15 x 10 x 8 x 5 = an air conditioner of 6,000 BTUs.
If you're concerned about how much energy an air conditioner will use, look out for one with a good energy efficiency ratio (EER). This is the ratio between an air conditioner's BTU and its the power input (in watts).
In general, the higher the EER rating the more efficient the air conditioner.
You could also look at the claimed energy class. Air conditioner manufacturers are obliged to self-certify their energy class, from A to G. However, we conduct our own tests, according to the European Standard BS EN 14511:2013, and we often find the claimed and actual energy class to be different.
If you're primarily after a dehumidifier, though, we recommend buying a dedicated dehumidifier instead.
With some air conditioner-come-dehumidifiers, you'll need to connect up a hose (often not supplied) to drain away the water. With others, you'll need to set the machine up as you would in air conditioning mode, with the hose out of the open window: something you wouldn't need to do with a standalone dehumidifier.
Having a range of fan speeds is useful, as it affects the rate at which your room cools down (and the noise the air conditioner makes). Three is a typical number of fan speeds. Many models also have a fan-only mode, which has no cooling effect and simply circulates the air within the room.
As with the dehumidification function, we don't recommend buying an air conditioner purely for the fan function. You can save on floorspace and money (and the faff involved in setting everything up) by just buying a fan instead.
Some models of air conditioner can be used as an electric heater, which could prove useful in winter.
Useful if you want to adjust the settings without moving from your seat. We put all smart air conditioners through a privacy and security test.
This reduces noise by running the compressor and fan more slowly. Often the target temperature will increase automatically across the night so that you don't wake up freezing cold. No air conditioner will be silent, even on sleep mode. You're better off pre-cooling your room before you go to bed, rather than attempting to sleep with an air conditioner running.
This allows you to set the machine to automatically switch on and off – useful if you want to come home to a cool house or save energy by having the unit switch off once you’ve fallen asleep. Pick a model with a clock and 24-hour setting. Some only have countdown or delay timers that need to be reset daily.
Here are a few pointers on getting your portable air conditioner set up correctly.
If your portable air conditioner comes with a window sealing kit, you'll only be able to use it if you have certain types of window. Generally, the window kits provided are only suitable for sliding or sash windows or French windows.
If you have a different type of window, you should still able to use the air conditioner with the hose extended through an open window, but this will work less efficiently and use more energy (the better the room is sealed, the less hard the air conditioner has to work).
However, with some windows even this may not be possible – for example, if your window opens from the top inwards, and the hose isn't long enough to reach. Make sure you have a suitable window before investing in a portable air conditioner.
We've tested portable air conditioners from a range of popular brands, including AEG, Argos own-brand Challenge, De'Longhi and ElectriQ.
For each air conditioner we assess a range of factors, including:
Here's how to keep your portable air conditioner in peak condition for as long as possible: