The Polyaire Derby exhaust fan is a compact, efficient ‘all in one’ ducted ventilator complete with non-return damper and 90 degree takeoff for easy installations in tight areas.
It is recommended to achieve a minimum of 10 air changes per hour in a bathroom, toilet or laundry, to remove excess moisture. To work out the recommended capacity needed for your room, calculate the volume of air in the room ( length x width x height, all in meters) and multiply this by the number of air changes to get the required air volume of the fan. (This will be adequate in most normal situations. We recommend that those clients who install in a bathroom who have a lot of glass and prefer to have warmer showers should get a fan double or more the recommended capacity.)
Note: If you install an exhaust fan with ducting, there will be a loss in capacity resulting in fewer air changes per hour. Use the pressure curve graphs to work out the likely capacity drop across the duct run.
The Derby exhaust fan comes in two models:
Models (with Capacity value)
100mm – 144m3/hr (40l/s) – Hole Size 230mm x 230mm
150mm – 234m3/hr (65l/s) – Hole Size 282mm x 282mm
Lead and Plug
Back draft stopper
Polyaire Derby Exhaust Fan 867400 / 867401
**Fan & components must be installed by Qualified Persons unless a lead and plug is fitted for a DIY installation**