Only if your cooker hood is set to recirculate.
Charcoal filters are designed to absorb odours in recirculating extractor fans—the type that doesn’t vent to the outside. If your fan is vented (i.e. ducted through a wall), then you do not need a charcoal filter at all.
If you do have a recirculating setup, that charcoal filter is your only line of defence. It needs replacing every 3 to 6 months, or it becomes useless—just blowing warm, greasy air back into your kitchen.
