Winter is quietly one of the worst seasons for London indoor air. Wood-burning stoves and open fires are a major and growing source of PM2.5 — a single evening's burning can raise particulate levels sharply, indoors and out. Add sealed-up, less-ventilated rooms and cooking, and winter indoor air often beats summer for particle counts.
Ready to clean up your London air?
Luggable MERV-13 kits deliver up to 681 m³/h CADR — built on the Corsi-Rosenthal principle, from £229. Ships from Oxford in 2–3 days.
Shop the UK store → See all kitsThe winter sources
- Wood burners & open fires — the big one for PM2.5.
- Gas cooking & heating — NO2 indoors.
- Reduced ventilation — pollutants build up with windows shut.
Staying warm and clean
If you burn wood, run a high-airflow purifier in the same room while the stove is lit and after. Ventilate briefly when cooking. A MERV-13 kit clears the particulates; add carbon for smoke odour.
Frequently asked questions
Are wood burners bad for indoor air?
Yes — they're a leading source of indoor and outdoor PM2.5. Running a purifier in the room while burning substantially cuts the particle load.
Is indoor air worse in winter?
Often, yes — wood burning, gas heating and reduced ventilation combine to raise indoor particle and NO2 levels.