- A plastic plenum box allowing up to 2 x 75mm ducts to connect to ceiling mounted room vents.
- One ventilation plenum box is required for each supply and extract air vent.
- Easy to fit, quick connect, no tools required.
- Use for air fresh air supply and stale humid ‘heat recovered’ extract air.
- Suitable for Passivhaus, air tight or any mechanical heat recovery ventilation system.
An important part of a semi rigid radial duct system is the ceiling vent plenum box. One is required for each supply and extract grille in each of your rooms to allow a balanced airflow throughout your house, flat or apartment.
Extract plenum boxes are required to be mounted in your kitchen, utility room and all other wet rooms including bathrooms, en-suites, showers and guest or annex bathrooms. Fresh air supply plenums are required for all habitable rooms to enable recovered heat to be transferred back into the dwelling.
The grille plenum consists of three parts; a standard 204x60mm adapter to allow the connection of 2 x 75mm semi rigid ducts, a 204x60mm flat duct with an 90 degree angled connection to 125mm dia and a short section of 125mm dia ducting. All three pieces simply push fit together to form a single unit. The single unit then allows the connection of your ceiling vent.
Generally one semi rigid duct is required to run from a manifold box to each grille plenum with the exception of long duct runs or larger kitchens.
It is best practice to use two duct runs (or even three with the 3 port metal plenum box) to reduce resistance (air pressure) to rooms that are a significant distance away from a mvhr heat recovery ventilator or rooms that require a higher airflow rate such at kitchens and pantries.