An air-quality sensor, which enables the machine to switch itself on when the air quality becomes poorer, can be useful. After all, you can’t see when the air quality dips, for example, as the result of a high pollen count. Another thing to look at is the Clean Air Delivery Rate (CADR) per watt as this helps you identify the most energy efficient air purifier. The higher the CADR/Watt rate the more energy efficient the air purifier is.

It’s speed makes it ideal for living rooms and bedrooms and it can be wall-hung to save space,” says Matt Thomas of John Lewis. This is because, rather than drawing in air from behind, it draws it from a ring around its front surface. There is also a ring of coloured light all round it, which changes from green to red according to the air quality levels. In smart mode it adjusts its power accordingly. Key specs – CADR: 280m³/h; Max room size: 35m²; Power settings: 4; Dimensions (WDH): 25 x 25 x 45cm; Weight: 3.8kg; Filter replacement indicator: Yes; Warranty: 2 years It may be at the pricier end of the scale, but the AEG AX7 must be the best-looking air purifier on the market. Ideal for living rooms, its five-stage purification system ensures the capture of up to 99.9% of all microscopic particles and bacteria and can clean the air in 60m 2 room in as little as seven minutes, while making no more noise than light rain. At the same time, it also has a three-in-one function, hot air, cold air, and air purification. Thanks to the hollow reality, we will not be injured by the hot wire of the hot airIt’s one of the best-looking air purifiers you can get, but the real attraction is the lifespan of the German-made filters, which can last up to 12 months depending on use. The device reminds you when they’re in need of replacement. Another nice feature is an intelligent auto mode, which senses how much pollution is in the room and chooses appropriately from its five speed settings. The best air purifiers for small rooms 1. Russell Hobbs RHAP1001B Clean Air Compact: Best budget air purifier

Otherwise, this has the same advantages as the smaller version: effective three-stage filtering, a built-in humidifying function and Sharp’s Plasmacluster ion technology, which – while it sounds like a weapon from a Halo game – works to kill odours, bacteria and mould. While the Vax PureAir 300 gives you even more airflow and covers larger rooms for less, the Sharp hits a sweet spot for price, performance and features, making it a great mid-range purifier for mid-sized rooms. Airpurtech brand promise is "make you air pure" and recently launched its new motto: "Airpurtech - make you air pure". If you’re looking at investing in an air purifier, you probably want to know how much it costs to run one. Matt Thomas, Lead Small Electricals Buyer at John Lewis, has noted a marked increase in air purifier sales. “Typically, we’ve seen families with young children, new parents and families where there’s a history of allergies or respiratory conditions being the early adopters,” he says. So if you have a 40 watt air purifier running at maximum speed and you wanted to know how much it would cost to have running for 24 hours solid – the sum would be as follows:

Definitely not against a wall (unless the unit has been specifically designed that way). Air purifiers need to draw in air and redistribute it, so leave an arm’s length of space around each side. Put it in the room you spend the most time in, usually your bedroom or your child’s bedroom. What is the Clean Air Delivery Rate (CADR)?