Philips Series 2000i (AC2939)

Philips has aimed the 2000i squarely at allergy and hay-fever users. Its AeraSense sensor tracks particulate levels and shows a numerical indoor allergen index plus a colour ring, so you can see the machine responding as pollen or dust rises. A dedicated allergen mode runs the fan harder at the fine-particle end, while auto mode handles day-to-day adjustment. The HEPA and active-carbon filtration covers pollen, pet dander and dust well. Philips markets it for rooms up to around 79 m2, but that uses a generous air-change rate; for proper allergy control treat it as a large-bedroom-to-living-room unit rather than a whole-floor solution. It's a capable, no-drama purifier. The main caveats are that app connectivity is more limited than the smart-first rivals here, and the genuine NanoProtect filters are best bought in advance so you're not caught out mid-season.