Indoor air is often worse than outdoor, here's what to do

What's in there with you

CO₂. Builds up when you sleep, work, or have people round. Over 1000ppm makes you sluggish. Over 1500ppm, decision-making and focus measurably drop.

VOCs. Volatile organic compounds from cleaning products, candles, air fresheners, paint, new furniture glue, vinyl floors, even dry-cleaned clothes.

PM2.5. Mostly from cooking on gas, vacuuming without a HEPA, candles, fireplaces, incense.

Formaldehyde. Off-gasses from new furniture, plywood, insulation. Worst in the first two years.

Mould spores. Anywhere humidity sits above 65% for hours.

Five things that fix most of it

1. Open the windows daily

Ten to fifteen minutes in the morning and again in the evening flushes out the CO₂ and VOCs. Skip on high-AQI days outside.

2. Always use the kitchen extractor

Especially on gas. Gas stoves emit NO₂, CO, and PM2.5 you can't see or smell.

3. HEPA purifier in the bedroom

You spend a third of your life there. HEPA plus carbon. Run it on low overnight.

4. Shoes off at the door

Shoes track in lead, pesticides, fungal spores, pollen. House dust drops by 60% with a no-shoes rule.

5. Houseplants are mostly symbolic

The famous NASA clean-air study is misunderstood. You'd need 100+ plants to measurably improve air quality in an average room. Plants are great for mood. Ventilation and filtration are what actually clean the air.

The most underrated gadget

A CO₂ monitor. Eighty dollars, lasts years, shows you exactly when the bedroom needs airing out. Most people are shocked at their numbers in the morning, often over 2000ppm.

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