Ventilation Ducting System & Semi Rigid Ducting | Flat & Flexible Duct Fan - Greenwood

What is Semi-Rigid Ducting?

Semi Rigid Ducting is essentially the mid point between rigid and flexible ducting.

  • It combines the performance benefits of rigid duct and the installation benefits of flexible duct.

  • Semi-Rigid Duct is classified the same as rigid duct in SAP

  • It is re-writing the ventilate rule book and is perfect for Heat Recovery System Installations. 

  • Click on the image to the left to see Semi Rigid duct in action in a 3 bedroom property with heat recovery

                        Semi Rigid ComfoTube Ducting                          

What is a radial system and what are the benefits?

 A radial system treats each room individually with a dedicated duct run.  For both supply and extract air, a manifold is connected directly from the unit and then each room has a direct run.

Radial Ducting for Heat Recovery Ventilation

With a manifold system, the resistance caused by duct is reduced, therefore Semi-Rigid duct resistance is very low.


The manifold takes mass airflow directly from the MVHR Heat Recovery Unit and allows lower rates to pass through to each individual room run

Directing mass flow to the manifold eliminates the need to increase the running speed of the MVHR Heat Recovery unit to overcome the resistance of duct which in turn causes noise for the homeowner

Semi Rigid Ducting for Heat Recovery Installations

Semi Rigid Duct is a perfect choice for MVHR Heat Recovery System Installations as it provides huge performance benefits whilst dramatically reducing installation time and installation risk on-site.

An MVHR Heat Recovery System requires a considerable amount of duct and air leakage occures within the duct network at the point where components are joined.

Comfotube requires no joins.

Comfotube can easily overcome site obstacles and can be worked through around joists with ease.

Did you know?

Semi Rigid Duct offers huge savings onsite - as a radial and flexible system it can be simply worked through and around the building structure without the need for a high number of connections;

 Semi Rigid Ducting

Semi Rigid Duct - ComfoTube Cleaning

ComfoTube is fully cleanable and one of the only systems on the market that is - making it ideal for Heat Recovery System installations as it offers long-term Guaranteed Installed Performance

Cleaning ensures that the performance of the MVHR system is maintained over the life of the unit and the installation

Cleaning of duct is a key focus in the new NHBC Best Practise Guidelines on Heat Recovery ventilating and is a crucial part of Guaranteed Installed Performance.


how clean is your air           

 ComfoTube as a smooth and patented interior called Clinside
                          Clean Ducting for heat recovery system 

  • This has been independently certified by a German Hygiene Institute for cleanliness
  • This prevents dirt and moisture getting trapped within the ridges of the system which inhibits mould and bacteria growth
  • Using the correct cleaning equipment between 95-98% of dust build up can be removed 

Our Ventilation Ducting System & Semi Rigid Ducting | Flat & Flexible Duct Fan range

  • Flat 51

    High Performance Semi-Rigid Duct designed for use with MVHR systems and ideal for apartments and houses where void space is very limited. Zero leakage and supplied on long rolls. No duct tape required. Radial System
  • ComfoTube

    ComfoTube is a range of high performance, semi-rigid duct ideal for use with MVHR installations. Zero leakage and supplied on long rolls to minimise connections and easily installed within the building structure. No tape. Fully cleanable. Radial system.


Click here to register for our latest promotions and updates


Facebook Twitter Pinterest Google Plus Linked In

Zehnder Group