Kitchen extractor fans help remove steam, grease particles, and cooking odours from the air while food is being prepared. In many homes the extractor fan is connected to ducting that carries air outside through an external wall or roof vent.

However, some kitchens have extractor fans that do not vent outside at all. Instead, the air may simply be filtered and recirculated back into the room, or vented into cupboards, ceiling voids, or loft spaces.

When this happens, moisture from cooking remains inside the property and can contribute to condensation problems.

Why Venting Outside Matters

Cooking generates large amounts of water vapour. Boiling pans, kettles, and steam from ovens all release moisture into the air.

If this moisture is not removed effectively, it can settle on cold surfaces such as windows, walls, and ceilings.

Over time this can lead to:

• Condensation forming on windows
• Grease build-up on cabinets and ceilings
• Mould developing in corners or behind cupboards
• Persistent cooking smells in the home

Proper ventilation removes this moisture before it has a chance to accumulate.

Signs the Extractor Fan Is Not Venting Outside

Some signs that your kitchen extractor fan is not venting outside include:

• Steam lingering in the kitchen long after cooking
• Windows becoming wet with condensation
• Grease deposits forming on cabinets and walls
• Strong cooking smells spreading throughout the house

In some homes the extractor hood may simply recirculate air through charcoal filters, which remove odours but do not remove moisture.

Why This Problem Occurs

Many modern kitchen extractor hoods are designed to operate in either recirculating mode or ducted mode.

If the extractor is installed without external ducting, it will simply filter the air and return it to the room. While this may reduce cooking smells, it does not remove humidity.

Blocked ducts, disconnected pipework, or poorly installed vents can also reduce the effectiveness of kitchen extraction.

How To Fix the Problem

The most effective solution is installing a ducted kitchen extractor fan that vents air directly outside the building.

This typically involves fitting ducting through an external wall or connecting it to a roof vent.

Proper ducting removes both moisture and cooking fumes, helping reduce condensation and improving indoor air quality.