Wall Ducting Kit
Wall ducting is the only option for a rear vented rangehood but it’s perfectly acceptable to duct a top vented through the wall. Where the rangehood is installed on an outside wall there is the advantage of it being the shortest route for air to travel to the outside. Building regulations state that the wall outlet should have shutters or a flap to prevent air flowing back to the inside. Some inspectors seem to favour a wall cowl, whilst others favour a shuttered vent. Quite simply the rangehood outlet is connected to the outside with a length of ducting and either a wall cowl or shuttered vent. Use only rigid or semi-rigid ducting for this installation as the use of flexible duct will certainly deliver poor results
As always, the quality of ducting is important to ensure the rangehood performs as it should and that noise is kept to a minimum. Ducting that disrupts the airflow will cause noise and reduce performance. Ducting that prevents the back-draft flaps from rising properly will restrict the airflow, strain the fan motor and increase noise.
A wall ducting kit will consist of 3m of semi-rigid ducting and either a wall cowl or shuttered outlet vent. It may also have a pair of ties but ducting tape is adequate to seal the duct ends to the rangehood and vent.
Vaned or Shuttered Vent Wall Cowl
Kitchen ventilation advice for New Zealand kitchens
Copyright Tom McKernan 2017