How Air Match works.
Air Match is a set of rules, not an AI model. It runs in your browser and gives the same answer every time for the same answers.
1. Sizing
Clean air needed (m3/h) = room area (sq ft) x 0.0929 x 2.75 m ceiling x 4.8 air changes an hour
That cleans the room's air about five times an hour, the usual rule for heavy pollution. A 144 sq ft bedroom needs 177 m3/h. A 300 sq ft living room needs 368 m3/h.
A model qualifies when the maker's published CADR (clean air delivery rate) meets the figure. When you pick a size band that has an upper limit, we size for the top of the band, so the match covers any room in it. "Over 600 sq ft" has no upper limit, so Air Match asks for your exact size. For spaces over 350 sq ft we also consider two units placed apart, and for whole floors and offices of 700 sq ft or more, three.
We do not size with models whose CADR the maker does not publish (today: Coway Airmega 50, Coway Airmega 100, Coway Airmega 350, Shark HP300, Dyson Purifier Big+Quiet BP02 and Dyson HushJet Purifier Compact HJ10). Where the only CADR is on a retailer or importer listing, the model page shows it marked "Not a maker's figure". You can still find these models in the shop.
2. Ranking
Among models that qualify, your priority counts most: quiet at night, yearly running cost, app and display, looks, or the most clean air for the size. Then fit for the space, noise, yearly filter cost, features, and clean air per rupee of the maker's price. Noise counts only when the figure is the maker's own. Models not sold as HEPA rank a little lower, and their card says so. People in the room change the order only in practical ways: a carbon stage for smoke, a pre-filter for pets, quieter units for children and older family members. We use no Amazon ratings, review counts or sales figures.
Budget is what you want to spend in total: when a plan needs two or three units, their combined price must fit. Budget bands use the maker's own store price seen on 13 Oct 2026, or the printed MRP where the maker runs no store; retailers often sell for less. A model above your budget never ranks above one inside it that qualifies. If nothing in your budget qualifies, we say so and show the closest matches above it, lowest price band first, clearly marked.
The top picks come from different brands, so you can compare, unless every other brand's best option scores well below a second model from the same brand. When quiet matters most, models without a maker's quiet-setting figure are left out of the top picks if at least three others have one.
3. What never affects the order
Retailers, commission rates, affiliate links, and whether Purispira stocks a model. The matching code has no access to any of them.
4. The Purispira package above the matches
Above the matches, Air Match shows what Purispira can install for your room. If we stock your top match, the package is built around it. If not, we offer the cheapest package with a stocked model, or a pair, whose maker's CADR reaches the clean air your room needs: small room ₹8,999, standard bedroom ₹12,999, large room ₹14,999, two purifiers ₹26,999, two large purifiers ₹28,999. When only one model in a size reaches it (the Qubo Q400 at 330 m3/h in the standard size, the Honeywell Air Touch V5 at 380 m3/h in the large size), the package names that model. Homes beyond two large purifiers get a free room test and a written plan; offices get a proforma. When the package costs more than your budget answer, we show the best size inside your budget first, with how much of the rule it covers. This block is separate from the ranking and never changes it.
5. Where the figures come from
Each maker's own product pages and spec sheets, checked on 13 Oct 2026, and the retailer listing where the maker publishes nothing. Every figure on a product page says whether it is the maker's figure, and notes any doubt, for example two different CADR figures on one brand page.
Yearly filter cost uses the maker's own store price for the genuine filter and the maker's filter life. Where the life is a range we use the middle; where the maker gives two figures we use the shorter; where the maker gives no life we assume a year and say so. When the maker's store shows the filter sold out, we still show the maker's price with that note, and rank on what a retailer charged that day. We do not show Amazon prices, ratings or review counts.
6. What Air Match does not do
It gives no health advice and makes no health claims. A purifier reduces PM2.5 in the room it is sized for. If you want the number for your own room, book a free room test.