Except perhaps in commercial settings, air conditioning is not as common in Britain as in some other countries like the US. Nevertheless, many homeowners have begun to seek ways to remain comfortable on the hottest days when a fan is not enough, and an air conditioner can be a good solution.

Air conditioners work in a similar way to refrigerators and are made from four essential parts: air is passed over an evaporator containing a refrigerant which cools the air. The warmed refrigerant is then pumped through a compressor to a condenser where the heat is radiated away. Continuing the refrigerator analogy, the room being cooled is the fridge cabinet and the outside world is the ‘heat sink’. Heat is exhausted from the unit via a venting duct that is usually snaked through a convenient door or window and ‘blocked in’ to prevent warm air returning to the room from outside.

Since cold air can hold less moisture than warm air, air conditioning causes evaporation of moisture at the evaporator. Most air conditioners try to evacuate some of this water down the venting duct but there is always also a drip collection-tray that will need to be emptied and sanitised occasionally. (By way of contrast, air coolers do not contain a refrigerant but are rather tower fans that pass air over water-dampened pads for an evaporative cooling action, and sometimes have trays to include ice for enhanced effect).

What to look for in an air conditioner

Air conditioners are rated according to the amount of heat in Btu’s that they can remove in one hour (one Btu is the amount of energy needed to raise the temperature of one pound of water through one Fahrenheit degree). We have reviewed conditioners rated between 8,000 and 12,000 Btu’s which will be sufficient for most domestic single-room purposes although smaller and more powerful units are available. As a rough guide, 8,000 Btu’s will be effective in a 12 x 12ft room and 12,000 Btu’s will be needed to cool a larger 18 x 15ft room with standard-height ceilings.

The cold air, of course, is very pleasant, but there are some disadvantages to portable air conditioners: they are heavy; can be noisy in operation; and can run up your electricity bill when operated continuously. All of the units we have highlighted have castors to assist in moving them around and we have taken account of reports of noisiness when available. Similarly, we have tried to identify running costs as far as possible, based on each manufacturers’ numbers or user reviews.

Added features available on some portable air conditioners that may be interesting include ‘heater’ and ‘dehumidifier’ modes, as well as variable speed fans and remote controls. Prices begin around £200 and range upwards for ‘better-name’ manufacturers and as capacity increases. They are not inexpensive machines but if the weather is making you hot under the collar then an air conditioner may be the machine to restore your equilibrium.

Best portable air conditioners

Prem I Air 9,000 Btu Portable Air Conditioner

Prem I Air 9000 BTU mobile air conditionerThe Prem I Air 9,000 is one of the least expensive units on the market but has sufficient capacity and features to make it worth consideration. It has an LED display panel and button controls to activate its different features. There are three ‘action’ modes: cool; dehumidify and fan (only), and two fan speed settings (high and low) along with power; sleep and swing buttons (the latter engaging a side-to-side blowing action). The manufacturer describes the conditioner as ‘self-evaporating’ but there is an excess drip tray and a warning light to advise when the tray is full. The unit weighs in at a relatively modest 23kg and stands 73cm high. It measures 33cm across its face and is 32cm front-to-back. It includes a 24-hr timer and a remote control and is supplied with ducting and a window adaptor.

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Inventor FCool 8,000 Btu Portable Air Conditioner

Inventor Fcool 8000 btu portable air conditionerThe Inventor Fcool 8,000 Btu conditioner is a basic, well-reviewed unit with three fan speeds and three working modes: cool, dehumidify and fan-only, all controlled via a four-button panel on the top of the machine or with the included remote control. A window kit and exhaust hose are also included in the package. Vanes on the front of the machine can be manually adjusted to direct the flow of cooled air. The conditioner has a white plastic casing and weighs 24kg and measures 79cm high x 30cm wide x 34.5cm deep. The manufacturer states typical energy usage is 0.95kW/Hr and provides a 2-year guarantee.

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EcoAir Artica 8,000 Btu Portable Air Conditioner

EcpAir Artica Cooling portable air conditionerA control panel on top of the machine has a small LED window for temperature adjustment and buttons for power on/off; mode ; sleep; fan speed and timer. There are three fan speeds and cool; dehumidify and fan-only modes; the timer has a 24 hour capability. The controls can also be accessed with the included remote control pad. This EcoAir machine includes a washable, mesh air filter and is described as ‘bucketless’ (although there is a drain tube available) and it is supplied with a flexible venting duct. It has a clean, solid design with a silver plastic exterior and measures 77cm x 32 cm x 40 cm (HxWxD) ; it weighs 24.5kg. Energy usage is quoted at 0.90kW/Hr. EcoAir manufactures a range of conditioners of different capacities and receives generally positive reviews.

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Igenix IG9901 9,000 Btu Portable Air Conditioner

Igenix IG9901 3 in 1 portable air conditionerIgenix is an Ipswich-based brand of household appliances including a range of air conditioners of which the 9901 is an example. The 9901 has a neat, compact design and features three fan speeds and a ‘sleep’ mode that gradually increases the temperature before switching off after 6 hours. An LED window on the front of the machine displays the target temperature while settings are entered either via the touch pad on the top of the unit or with the remote control; there is a 24-hour timer facility. The conditioner is described as ‘self-evaporating’, reducing the need to empty the water tank. At 22kg, it is a relative lightweight. The manufacturer offers a 2-year guarantee that can be registered on-line.

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EcoAir Apollo Heating and Cooling 12,000 Btu Portable Air Conditioner

EcoAir Apollo heating and cooling portable air conditionerEcoAir’s ‘Apollo’ air conditioner, with a 12,000 Btu capability, has the largest cooling capacity of our picks. It comes with a wireless remote control and features three fan speeds; a 24-hour timer; a ‘sleep’ function; and a heating mode as well as the usual ‘cool’ and ‘dehumidify’ modes. The design is clean and modern and the manual controls are grouped around a small LED window on the top of the machine. It incorporates a washable, mesh air filter and is ‘bucketless’ with a self-evaporating design. It weighs 39kg and its operative power consumption is 1.25kW/hr.

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De’Longhi N87 Pinguino Silent Air Conditioner

Delonghi PAC N87 Pinguino portable air conditionerThe N87 is a 9,800 Btu air conditioner from the De’Longhi range. The manufacturer is a well-regarded Italian brand, based in Treviso. The air conditioner has three fan speeds: maximum, medium and ‘silent’ (which is actually <50 decibels, only) and three modes: cool; dehumidify and fan-only. Controls are set via a soft-touch keypad with built-in LED in the top of the unit, or by using the wireless remote. It features a condensate recirculation system; it uses R410A ecologically-friendly refrigerant and is designed to be energy efficient. Weighing 30kg, this is a well-built, up-to-date air conditioner.

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Best Air Conditioners Summary

 PriceCooling capacity (Btu)Size H / W / D (cm)Weight (kg)Energy usage (KW/hr)Room size (m)Comments
Prem I Air 9000£230900073 x 33 x 3223N/S5 x 4Worth considering
Inventor F.Cool£260800079 x 30 x 34.5240.954 x 4Best seller
EcoAir ARTICA£300800077 x 32 x 4024.50.94 x 4Solid choice
Igenix IG 9901£305900068 x 32 x 31220.95 x 4Compact
EcoAir APOLLO£4101200082 x 39x 41391.256 x 5Well reviewed
De'Longhi PAC N87£500980075 x 45 x 40300.96 x 4'Silent'