Do air purifiers actually make a difference?

For specific problems — allergies, asthma, pets, dust — yes, a good air purifier makes a measurable difference to airborne particle concentrations. Studies have shown reduced allergen levels and improved allergy symptoms in people using HEPA air purifiers in their bedrooms and living spaces. For a healthy person in a well-ventilated home with no particular air quality concerns, the benefit is smaller and harder to perceive.

How much does it cost to run an air purifier?

A typical home air purifier uses 10-60W depending on fan speed. Running a 30W purifier for 8 hours a day at the UK unit rate of around 24p/kWh costs approximately 58p per day, or £17 per month, or £212 per year in electricity. Add filter replacement costs of £25-50 per year and total annual running cost is roughly £250-260. A more energy-efficient unit on sleep mode costs significantly less.

Are Air Purifiers Worth It? An Honest Answer

Air purifiers are a category that attracts a lot of marketing noise. Brands imply they'll solve everything from fatigue to COVID. The reality is more specific: they do some things well, other things not at all, and for some people the benefit is obvious while for others it's marginal.

Here's a direct answer to whether one is worth buying for you.

Who Noticeably Benefits

Allergy and hay fever sufferers. This is the strongest evidence base. Multiple studies have found reduced allergen concentrations and improved symptom scores in allergy sufferers using HEPA purifiers in their homes. The effect is most pronounced in bedrooms — the room where you spend the most continuous time — and during pollen season when indoor concentrations spike.

If you have diagnosed allergies and your symptoms are noticeably worse indoors than outdoors during allergy season, or if you wake up congested and it clears within an hour of getting up and out of the room, you'll likely notice a genuine improvement.

Asthma sufferers. Similar evidence base to allergies. Reduced exposure to airborne triggers correlates with reduced symptom frequency in studies. The benefit depends on what your personal triggers are — if your asthma is triggered primarily by cold air or exercise rather than indoor allergens, an air purifier helps less.

Pet owners. If you have animals that shed, an air purifier running in the main living areas measurably reduces airborne dander concentration. People with mild pet allergies who can't give up their animals often find an air purifier makes cohabitation tolerable.

People living near busy roads. PM2.5 from vehicle exhaust penetrates indoors even with windows closed. Studies in urban areas have found HEPA purifiers reduce indoor PM2.5 by 50-70% in homes near major roads. Whether that matters to you depends on how close you are and how much you care about long-term particulate exposure.

Parents of young children. Infants and toddlers have faster breathing rates than adults, so equivalent air quality represents proportionally greater exposure. If you have a baby with eczema or respiratory issues, there's a reasonable case for an air purifier in the nursery.

Who Probably Won't Notice Much

Healthy adults in well-ventilated homes. If you regularly open windows, live in a low-traffic area, don't have pets, and don't have allergies or respiratory conditions, your indoor air quality is probably already reasonable. An air purifier will reduce particle counts further, but you're unlikely to notice a subjective difference.

People buying them for general "wellness." Vague claims about "toxins" and "better focus" from clean air are not well supported. The measurable benefits are specific: particles, allergens, some odours. If you don't have a particular problem to solve, the benefit is speculative.

Anyone who expects them to fix humidity or condensation. This is worth reiterating because it's a common mistake. An air purifier does nothing for damp, condensation or humidity. If your home feels stuffy because it's damp, you need a dehumidifier and better ventilation.

The Honest Cost Calculation

A decent air purifier costs £80-200 to buy. Then there are running costs:

Electricity. Running a 30W purifier for 8 hours a day costs roughly £17-18 per month at current UK unit rates. Running it 24 hours a day costs around £52 per month. Most people run them on auto mode or sleep mode, which significantly reduces consumption.

Filters. Replacement filters cost £25-50 per year for most models. The Philips Series 3000i is an outlier with a 36-month filter at higher cost but lower annualised expense.

Total annual running cost. Roughly £100-250 depending on usage and model. Over five years, a £120 purifier might cost £600-700 in total including electricity and filters.

Is that worth it? For someone with moderate to severe allergies or asthma: almost certainly yes. The reduction in symptoms, reduced reliance on antihistamines, and improved sleep quality over five years is worth more than £700. For someone without those conditions: possibly not, unless there's a specific air quality problem you're trying to solve.

The Cheaper Alternatives First

Before buying an air purifier, it's worth checking:

Ventilation. Opening windows for 10-15 minutes in the morning dilutes indoor pollutants significantly, at zero cost. In a house with good airflow, this achieves a lot of what a purifier does.

Hoovering with a HEPA-filtered vacuum. Reduces settled allergens that an air purifier can't reach. A HEPA vacuum is a more cost-effective first step for dust mite allergy than an air purifier.

Allergen-proof mattress and pillow covers. For dust mite allergy, these reduce allergen exposure at the source — the bed — which is where most exposure happens. They cost £20-50 and last for years.

Removing the trigger. If the problem is cigarette smoke from a housemate smoking indoors, the most effective solution isn't an air purifier.

None of this means air purifiers aren't useful. It means they're more useful as part of a broader approach than as the sole intervention.

See our full air purifier roundup for product recommendations, our running cost breakdown for detailed electricity calculations, or our budget picks if cost is the main concern.