Frost protection The heater can be set to heat automatically when the temperature drops below 5°C, but you'll need to have it on standby for it to run, so this can limit its usefulness. Some modern options also have smart features so you can program them via companion apps and smart speakers. Adjustable thermostat Using this function, a portable heater will heat the room and when the desired temperature is reached, it will try to maintain the room at that temperature. Most of the cheaper, simpler heaters we tested have a dial thermostat that doesn't let you choose specific temperatures in °C. You'll likely need to buy a more expensive model for that. Our tests also found that they're rarely 100% accurate and will probably think the room is a couple of °C warmer or cooler than it is. It’s easy to use, has a timer and a great natural breeze setting, and is reasonably powerful by compact tower fan standards; we measured the maximum airflow at 2.2m/sec. It’s also light enough to lug around everywhere, which is handy in a heatwave. Throw in low energy consumption, even at higher speeds, and this is the best of the compact options. Read our full story on illegal and dangerous plug-in mini heaters for sale on online marketplaces to see those we identified as having serious safety risks.

If you were to try replacing the use of your central heating by putting an electric heater in each room, it will definitely end up costing much more.We buy all the electric heaters we test. We put the bestselling heaters from popular UK retailers through these tests: Heating speed, evenness, and accuracy Central heating is much more effective at maintaining a stable temperature over a longer period, whereas the heat from an electric heater will soon dissipate if the rest of your home is cold.

Keen to optimise home heating? See our advice on boiler controls and thermostats , smart meters , and loft insulation The oil in the radiator acts as a heat reservoir, which stays hot for some time after the heater's switched off. Some are called 'oil-free' and function in a comparable way, just with an internal heating element instead of any oil. And a fourth user put forth the following question: “@bmstores Would you be willing to donate some fans to be shared around to the various children’s wards at Southampton Children’s Hospital? They are crying out for them like a sauna up on the kids’ wards and paediatric emergency dept.” Key specs – Dimensions: 107 x 30 x 30cm; Weight: 5.7kg; Oscillation angle: 60˚; Cord length: 1.8m; Warranty: 2yr; Power: 45WThese have exposed heating elements, which heat up cold air as it passes. This often leads to slower, but more even, heating. They tend to be a little slower than fan heaters, but are quieter, and our tests found some are still pretty speedy.