PART F · Ventilation
Bathroom and kitchen extractor fans explained
Bathroom and kitchen extract ventilation removes moisture and pollutants near their source. The fan needs to be selected and installed as part of the ventilation system. A large airflow figure on the box does not prove that the fitted system performs adequately.
Does a cooker hood count
A hood that recirculates air back into the room should not be assumed to provide the required extract ventilation. It can filter some cooking pollutants, but it does not discharge moisture outside in the same way as an extract system.
Ask how the kitchen's required ventilation is provided and whether the hood forms part of that arrangement.
Why does the duct route matter
Long routes, bends and unsuitable terminals can reduce performance. The installed airflow may differ from the manufacturer's headline figure.
Choose the duct route before ceilings and cupboards are fixed. Avoid treating a convenient space above a ceiling as a substitute for a designed discharge route.
Should the fan run continuously
That depends on the system. Intermittent extract, continuous extract and heat recovery arrangements have different operation and control needs.
Ask which components should remain running, when boost settings are used and how incoming air is provided. Switching off a continuous system may undermine its intended performance.
What should be checked at completion
Confirm the applicable Part F requirements, relevant airflow measurements, controls and commissioning records. Obtain clear operating and maintenance instructions.
Noise deserves attention because an irritating system is more likely to be turned off. Suitable equipment and installation should address that practical issue without sacrificing ventilation.
For an extension or refurbishment, review existing rooms as well as the new fan. A kitchen relocated to the centre of a house, for example, needs an achievable duct and ventilation design before the room layout is finalised.