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.

Key specs – Dimensions: 107 x 30 x 30cm; Weight: 5.7kg; Oscillation angle: 60˚; Cord length: 1.8m; Warranty: 2yr; Power: 45W Convector heaters are usually taller than fan heaters, but thin and light – making them larger, but still relatively easy to move between rooms.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.

We set up each heater in the centre of our test room and run it on the maximum settings, with the room starting at a cool temperature. We monitor how much the room temperature changed over the course of an hour using temperature probes. We found the most drastic changes happen in the first half an hour and increases in temperature become more incremental after that. These can still be bought, but they aren't as popular or widely available as fan or convector heaters. Decided that a tower fan is for you? Well, now your choice comes down to size and features. Generally speaking, the larger and taller the fan, the higher the airflow and the bigger the room it can cool, with the added bonus that you might not have to push it so hard to have the same effect. This means you can run the fan at a slower speed with – usually – less noise. That’s handy, as noise is the second-biggest factor. A noisy tower fan can be distracting in the daytime, but a real issue if it stops you dropping off to sleep at night. Portable electric heaters use electricity, which costs 27.35p/kWh under the current energy price cap. Depending on how effective the heater is, they can take anything from 30 minutes to an hour to notably raise the temperature of a medium-sized room, so if you're only planning on using it until the room gets up to temperature, it will likely cost you between 28 and 55p.Unwanted Food or Drink Products - Once supply conditions are broken, there are a number of factors outside of our control that can affect the quality of a product. Therefore perishable goods such as food and drink cannot be returned. Oscillation is the other key feature. Nearly all tower fans oscillate, turning slowly from side to side to cover a larger area, but they differ in how wide the angle of oscillation is. Again, the bigger the space you want to cool, the wider you want it – and you can always turn oscillation off if you just want to keep yourself comfortable. How we test tower fans

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. 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. Key specs – Dimensions: 54 x 15 x 14cm; Weight: 2.4kg; Oscillation angle: 90˚; Cord length: 1.6m; Warranty: 2yr; Power: 18WOur fan tests start with a battery of airflow tests, where we measure the speed of the air pushed through the fan at a distance of 1m with an anemometer. We test at maximum and minimum fan speed settings, plus a medium setting in-between. We also measure sound levels at these settings, along with power consumption at the highest and lowest. From there, we use the fan in a selection of different rooms to gauge how effectively they work in different situations and layouts. We also try out any special modes and get to grips with both the built-in controls and the remote control, if supplied. What controls and features should you look for?

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. You can never bank on getting hot weather in the UK but, when it does come, it can come with a thump. When the mercury rises and the air stays still, it’s almost impossible to escape the humidity and heat, yet – for most of us – air conditioning is overkill. Get hold of a fan, however, and you can get a breeze going inside your home and make the temperature a bit more bearable. Put one in the lounge and you can properly chill out; get one in the bedroom and you might just get some sleep. They tend to be cheap to run, but some can be really slow to heat up. Most oil-filled heaters are also fairly heavy and cumbersome, so look out for models that come with wheels. 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.

This isn’t the perfect fan for sleepers, as even on its lowest setting it’s far from silent, but it’s fine for cooling down a small living room or taking some heat out of the bedroom before sleep. Looking for maximum cooling for a minimal cost? The Igenix is pretty hard to beat. We assess how easily each electric heater can be set up and how easily understandable the controls and settings are. We used any handles to lift the heater and move it around. While some heaters can be used straight out of the box, others have complicated program and timer settings. A third added: “Bought three of these yesterday, so needed in this heat” with a fire emoji, while a fourth chimed in: “I definitely need one of these - 35 weeks pregnant in this heat” Cold air setting Some fan heaters can help cool you down too. They're not nearly as effective as a dedicated air conditioner, but a light breeze of cold air is better than nothing.