Does an air purifier help with mould?

Short answer: yes for the airborne spores and the smell, no for the patch on the wall. Here's exactly where an air purifier fits — with none of the over-promising most sites do.

What an air purifier does do

Mould reproduces by launching microscopic spores into the air, where they drift for hours before settling on the next damp surface. A MERV-13 air purifier captures around 93% of airborne particles, including most of those spores. Running one continuously lowers the spore count you breathe and slows how quickly mould spreads to fresh spots — which matters most in a bedroom, where you spend hours breathing the same air.

What it does not do

Be clear-eyed about the limits. A purifier can't kill or remove mould already growing on a wall, ceiling or sealant — that colony has to be physically cleaned off. And it can't fix the damp that feeds mould in the first place. Anyone claiming a purifier alone "gets rid of mould" is overselling it.

The smell is a separate job

That musty, earthy odour is a gas (microbial VOCs) given off by active mould, and particle filters don't catch gases. If the smell bothers you, choose the Carbon model, which adds an activated-carbon stage for odour on top of spore capture.

The complete approach

Use the purifier as one layer of three: (1) clean visible mould with an appropriate mould remover; (2) fix the moisture — ventilation, extractor fans, stop drying washing indoors, and a dehumidifier if humidity stays high; (3) run a MERV-13 purifier to capture the spores in the air while you do the first two. Together they work; alone, none is enough.