Air Purification

Air Purification

Two related problems, and it is worth knowing which one you have. Damp air brings condensation on windows, black mould in corners and washing that will not dry, and that needs a dehumidifier. Dirty air carries dust, pollen, pet dander and cooking odours, and that needs an air purifier. They are different machines doing different jobs, though several units here combine both. Power draw is the practical difference in running them: an air purifier is a fan pushing air through a filter and typically sits in the tens of watts, so it is designed to run continuously, while a compressor dehumidifier runs a refrigeration cycle and draws substantially more, which is why the better models let you set a target humidity and cycle rather than running flat out. Check the wattage stated on each product page, since it varies widely between models even within one brand.

Dehumidifiers

Extraction rate in litres per day is the figure to work from. 10 to 12 litres suits an apartment or two bedrooms, 16 to 20 litres handles a full house with persistent condensation, and 30 litres covers large or badly affected spaces including the industrial unit for unheated buildings. Compact 600ml to 900ml units suit a wardrobe, caravan or single room, and passive moisture absorbers in 450g and 680g need no power at all and take refill sets. Smart models let you set a target humidity so the machine cycles rather than running continuously. Dimplex EverDri, DeLonghi Tasciugo AriaDry, Russell Hobbs, De Vielle, Black & Decker, Princess, Prem-I-Air and Bonura cover the range, and the Masterplug Puredry SmartEnergy 3-in-1 combines dehumidifier, purifier and ioniser in 12 litre and 20 litre.

Air Purifiers

Air purifiers pull room air through a filter, and HEPA is the standard worth having because it traps the fine particles that matter for hay fever, asthma and homes with pets. Match the unit to the space: plug-in models handle a kitchen or bathroom, mid-size units suit a bedroom, and floor units cover living rooms and offices. Filter replacement is the running cost to watch rather than electricity, and the Shark NeverChange5 range is built to run five years before a filter change. Dyson combines purification with air movement across the Pure Cool, Cool Formaldehyde, Humidify + Cool, Hot + Cool and compact HushJet ranges, so one machine works year round. Shark covers NeverChange5 in standard, Max and Compact Pro, a 3-in-1 HEPA model and a 67W four-fan unit, PureAir plug-in, room and large-space units plus a fridge purifier, and Russell Hobbs a compact touch control model. See also Heating, Cooling & Air Treatment.