We find a lot of customers get these units for bedrooms,” says Appliance Direct’s Jake Crossley. “7,000 BTUs is the output we would recommend for rooms up to 18 square metres. Any larger and you won’t get the full benefit.” It’s an effective cooler, taking a 25°C room to 21°C within half an hour, and to 20°C over a further 30 minutes, after which it kept the temperature steady for another hour. Testing in the middle of a heatwave, this was sweet relief. However, take any claims of silent running with a pinch of salt; noise levels hit 52dB at full tilt, falling to 46dB once the temperature had stabilised. Power consumption can also reach 620 to 820W when the unit is working hard. It isn’t the cheapest PAC to buy or run, but if you need some serious cooling, it’s exactly what you need. In Cool mode, it hovered at around 667W with the fan speed set to low and rose to around 672W with the fan at high speed. That’s with the temperature set to its coldest level of 16℃, so over time that should fall to a lower level. We do wish it had a lower fan speed to keep the noise levels down but, having said that, this isn’t all that different from most air conditioners at around this price. MeacoCool MC 7000: Is it energy-efficient?

Kandola says the most popular options for portable air conditioners are 9,000 and 12,000 BTU, which would cool a room of around 21 and 30 square metres respectively. Remember that the exhaust pipe will need to be run outside through a window and the gap sealed if possible. Window kits are sold for this purpose - see below. Do portable air conditioners use a lot of electricity? Air-conditioning units don’t get much more reasonably priced than the MeacoCool MC 7000. Suitable for rooms up to 22m² thanks to its 7,000 BTU rating, the unit includes two fan speeds, as well as dehumidifier and fan functions. It’s reasonably compact, too, measuring less than a metre tall and 35cm square. At 21kg, it’s also more realistically portable than some PACs; you can just about lug it from room to room without risking a hernia.

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The only major downsides are noise and power consumption. The MC Series 7000 outputs around 58dBA in typical use, and is only a few decibels quieter with the fan on its lower setting. And while it uses around 104W while cooling, we saw that rise to peaks of 641W during dehumidification – although the way the dry mode works means that this isn’t constant, by any means. Still, you’ll hear the same complaints of most PACs, but you can easily live with such issues when the price is so low and the performance so impressive. Further down, we recommend their EL98 model which is more powerful, at 11,000 BTU. But this smaller, cheaper N82 is slightly cheaper to run (at 27p per hour rather than 33p) and boasts many of the same features, including an LED control panel and thermostat, making it our top choice for most families. It’s also about as quiet as air conditioners get: 52dB compares to the murmur of a quiet office. Note: The window kit is only designed to be installed with sliding windows or doors. The window kit is not designed or to be used with casement style windows.

You get two window kits with the supplied 1.8m duct as standard – a fabric one designed to be attached via supplied Velcro strips, plus one that comprises a trio of hard plastic window ‘plates’. When joined together, the latter also allows you to vent the duct through a sliding door – though you’ll be left with a small gap at the top. This is still far better than the window kits offered with most air conditioners, a big point in the Meaco’s favour. I tested the unit over a couple of humid days in my home office and bedroom, both of which measure around 26m2, the upper volume limit for the unit. Weighing in at 23.5kg it is – just – possible to get the unit up a flight of stairs single-handed, but nul points to Meaco for the shallow finger-grips.Key specs – BTU rating: 9,000; Functions: AC, dehumidifier, heater, fan; Energy rating: A; Noise: 64dB; Features: Remote control, timer, three-speed fan, heat pump; Hose length: 1.5m; Dimensions: 705 x 472 x 383mm; Weight: 31kg to 34kg

Designed in Guildford and manufactured in China, Meaco’s MC9000 is intended to cool rooms of between 16 and 26 square metres. Given that the average new-build UK living room is a little over 17 square metres in volume, that makes this model a prime candidate for most homes. Non-Disruptive: Designed with an advanced sleep mode that can be programmed to switch off after a desired time to allow you to fall into a deep sleep at night. The running costs of around 25 to 35p per hour will seem reasonable value for money the next time temperatures rise. Most have a Class A energy rating.When we talk about BTU per hour (BTU/h) for air conditioners, we mean the cooling capacity per hour. The larger the room to be cooled, the greater the cooling capacity (BTU/h) should be. Most mobile cooling systems start at 4000 - 5000 BTU/h, while a 7000 BTU air conditioner is of average consumption. How to choose the right BTU capacity for an Air Conditioner? Great for small rooms, caravans, boats or where space is limited, the cooling fan function is perfect when you need to cool one part of your room - ideal for when you're on your own or don't want to waste time and money cooling unnecessary areas. As for running costs, a higher BTU rating generally means the PAC will be doing more work and consuming more energy, but not all units are created equal. Your air conditioner should have an energy efficiency class, from A++ down to G, just like your fridge or cooker. The higher the class, the more efficient the unit will be. Are there any other features I should look out for? Free unlimited phone support with a UK Dedicated claims line need a repair. We have a dedicated claims line and are here to help.