®Compared with formaldehyde, dampness brings musty odours, mould and dust mites that are easily overlooked — yet they are common triggers of allergies, asthma and everyday respiratory discomfort.
Why humidity matters
Relative humidity above 60% for long periods favours mould and dust mites; too low and mucous membranes dry out, static builds up and the air feels unpleasant. Holding indoor relative humidity between 40% and 60% is the more comfortable and healthier target.
Common warning signs
- Mould patches or black spots at wall corners and window frames;
- Musty smells on clothes and bedding, especially in humid seasons;
- Allergic rhinitis or a recurring cough that is worse at home;
- Persistently damp corners in bathrooms and kitchens.
What to do
- Control humidity first: use a dehumidifier or the dry mode on the air conditioner to bring it into range;
- Repair seepage and leaks promptly, never let water sit;
- Keep ventilating, and clean and air fabrics and carpets regularly;
- Treat mould early, before spores spread.
Treating air is not only "removing formaldehyde" — humidity control and mould prevention matter just as much, especially in humid southern regions where they return a lot for the money.