Local extract fans

Description
Electrical fan usually installed in bathrooms, kitchens and toilets to provide rapid ventilation.

Unit cost of installation
From £150 dependant on size and method of installation.

Bulk cost of installation
Data not available

Maintenance
Periodic cleaning.

Lifetime
15 years.

Technical suitability
Can be fitted in a variety of positions (through wall, in windows and in ceilings). Operation can be manual or by humidity sensors.

Care should be taken if installing extract fans in dwellings with open-flue combustion appliances because in some circumstances the operation of the fan could cause spillage of combustion gases back into the room. This can occur even if the combustion appliance is in a different room to the extract fan(s). Mechanical extract fans should not be installed in the same room as solid fuel appliances. Technical guidance referred to below should be consulted if open-flued appliances are present in the dwelling.

Non-technical constraints
User perceptions of running costs and heat being drawn out of dwelling can lead to units being disabled. Some units can be noisy especially if not maintained properly or if they are mounted in plasterboard.

Potential concerns with fuel poor
No specific issues.

Ancillary benefits
Extraction of moisture vapour from source results in lower risk of condensation and damage to fabric of building and occupants' possessions from mould growth.

Trigger points for work
Refurbishment of kitchens and bathrooms. Any major refurbishment of the dwelling where there has been a significant improvement in airtightness.

Performance Limitations

Technical Guidance Available
» Approved Document F 'Ventilation'
» OFTEC Technical Information Sheet T1/112 'Oil fired Appliances and Extract Fans'
» BRE Information Paper 21/92 'Spillage of flue gases from open-flued combustion appliances' 1992