Indoor air quality: airing out, pollution sources, CO2
Home air is often more loaded than you think: ventilating daily, limiting its sources, and spotting stuffiness can improve it.
- Ventilation
- Pollution sources
- CO2
Indoor air quality at a glance
The most useful gesture costs nothing: open wide every day, especially when cooking or cleaning, and reduce what loads the air.
- Guidelines read on
- October 20, 2026
- In your home
- My home in 6 questions
Indoor air quality
Airing out: the basic step
Opening wide, even in winter, drives out water vapor, cooking odors, and compounds that build up in closed rooms. EPA notes that inadequate ventilation raises indoor pollutant levels by not bringing in enough outdoor air. Ventilation takes over the rest of the time: keep air inlets and extractor fans clear and working, especially when cooking or showering.
Indoor sources that release gases or particles are the primary cause of indoor air problems; inadequate ventilation raises indoor pollutant levels; high temperature and humidity can raise some of them.
US Environmental Protection Agency : Introduction to Indoor Air QualityA guideline on indoor air quality in homes, to raise awareness of its importance and of how to achieve good air quality.
NICE : Indoor air quality at home (NG149)
Who to consultYou; a professional if the mechanical ventilation no longer works.
Where indoor air pollution comes from
According to EPA, indoor sources that release gases or particles are the primary cause of indoor air problems. Many are in the home itself: combustion appliances, tobacco, cleaning and DIY products, air fresheners, candles and incense, new furniture and materials, not to mention mold, dust mites, and radon. Do not smoke indoors, measure out products, and ventilate after use.
Indoor sources that release gases or particles are the primary cause of indoor air problems; inadequate ventilation raises indoor pollutant levels; high temperature and humidity can raise some of them.
US Environmental Protection Agency : Introduction to Indoor Air Quality
CO2, a sign of stale air
The carbon dioxide we exhale builds up when the air is not renewed: it serves as a sign of stuffiness. A high level signals that the room is not ventilated enough. At home, a CO2 sensor can show when an occupied room needs fresh air; the answer remains the same: open wide.
Official pointers, not a diagnosis: for any risk, the named authority is the reference.
Indoor air quality: your questions
How long should you ventilate your home each day?
Public guidance differs from one country to another, but it agrees on the principle: open wide every day, summer and winter, and more during and after cooking, cleaning, DIY work, or a shower. The rest of the time, keep extractor fans and vents working.
Do plants clean the air in your home?
Not in any notable way: France’s observatory for indoor environmental quality judges their effect weak in a real home. Keep them for the pleasure they give. For the air, renewing it and reducing sources come first, and a purifier comes only as a last resort.
Do candles and incense pollute indoor air?
They release particles and compounds that load the air, especially for sensitive people. Use them in moderation and open up afterward. If you hold to a ritual with smoke, keep the window open during and after, and reserve it for special occasions.
Official guidelines read on the original pages on October 20, 2026, reread at each quarterly review.
Read also
And in your home, what should you check?
Six questions about your home tell you what deserves checking, with the public contact for each point.
Check my home in 6 questions Free, no account · nothing is sent · no score