In our experience the majority of extract fan failures are caused by the under powered fans and the duct runs being too long and/or with too many bends. To prepare the extract vents the following guidelines should be followed:
- Is the ductwork of the type specified by the manufacturer?
- Have the number of duct bends been minimised to ensure adequate air flow and least resistance?
- The Flexible duct provided should only be used to connect the unit to the central diffuser (this is important for the acoustic performance of the product).
- Have recommended duct jointing collars and components been used to ensure appropriate duct performance (duct runs should be as air tight as possible)? Note: All the joints should be sealed correctly using the collars provided.
- Is the fan correctly specified for the room/task?
- Is the fan correctly situated, secured and adjusted?
- Do all internal doors have 10mm undercuts? (as required in “Domestic Ventilation Compliance Guide” Part 2b Table 2.3a)
- Has the electrician set fan speed using manufacturer’s data table
- Has the unit been installed in a position that will permit access for maintenance purposes.
We always advise our clients to contact us as early as possible to ensure that your preceded enclosure stands the best chance of passing the extract vent testing. When we send out our quotation we also forward a specific extract fan testing checklist to help our client prepare for the testing.