Prevents condensation water running back down the duct towards the fan. This could potentially cause a fault, therefore Airflow Developments recommends the use of a condensation trap in its ducting systems. This is in line with the best guidance from the building regulations document part F. This product is for use with 100mm diameter round ducting and has a 21.5mm connection for a PVCU overflow waste pipe.
Preventing mould and condensation in the property also involves protecting from condensation in the ducting and unit.