The Best Air Purifiers for Allergies and Hay Fever

Yes, within limits. A purifier with true HEPA filtration removes a large share of the airborne pollen, dust and pet dander passing through it, which can reduce symptoms, especially overnight in a bedroom with the windows shut. It won't help with allergens that have already settled on surfaces or in bedding, so pair it with regular vacuuming (ideally with a HEPA vacuum) and washing bedding at 60C where you can.

Look for true HEPA, ideally H13, which captures at least 99.95% of the hardest-to-trap particle sizes in a single pass. Be wary of vague phrases like 'HEPA-type' or 'HEPA-like'. A fully sealed system, where air can't bypass the filter, is a further step up because it stops filtered allergens leaking back into the room. Blueair's HEPASilent is a slightly different electrostatic-plus-mechanical approach that also captures fine particles effectively.

Match the purifier's clean-air delivery (CADR) to your room's floor area, and aim for a model that can cycle the air at least four to five times an hour for allergy control. Manufacturers often quote a headline room size based on a much lower air-change rate, so treat those figures as a maximum and size up rather than down. A unit rated only for small rooms will struggle in an open-plan living space.

For allergy control it's best to run it continuously on a low or auto setting, as airborne allergens are constantly replenished whenever doors open or people move about. Most models have a quiet night mode that's fine to leave on while you sleep, which is often when relief matters most. Remember to check and replace filters on schedule, as a clogged filter cuts performance.

Budget roughly £25-£75 per filter depending on the model, usually replaced once or twice a year with typical use. Compact units like the Blueair are cheapest to feed, while premium combined HEPA-and-carbon filters (Dyson, Philips) sit at the top end. Factor this in alongside the purchase price, and buy genuine filters where possible, cheap 'compatible' filters can use lower-grade media that underperforms on fine allergens.

For allergies specifically, HEPA does the heavy lifting, as pollen, dust and dander are particles. Activated carbon targets gases and odours rather than allergens, so it's a useful bonus (for cooking smells, pets or VOCs) but not essential for symptom relief. Every pick here includes a carbon layer, so you get both, just don't pay a premium for carbon alone if pure allergy filtration is your goal.

Purely mechanical HEPA units produce no ozone. Some ionisers can generate trace ozone, which can irritate airways, so it's sensible to check for an ozone-free claim or a switchable ioniser. Blueair states its HEPASilent electrostatic process is ozone-free, and the other picks here rely on mechanical HEPA filtration. If in doubt, choose a sealed or true-HEPA model without a standalone ioniser.

Place it where you spend the most time and where air can circulate freely around it, typically the bedroom for overnight relief, with a gap of 15-30cm from walls and furniture so intake and outflow aren't blocked. Keep it off the floor behind curtains or sofas, and run it with the door and windows closed during pollen peaks so it isn't fighting a constant influx of fresh allergens.