VentilFlex – the most effective choice for relining ventilation ducts in Church of Sweden’s apartment building
A forty unit apartment building owned by the parish of Maria Magdalena of Church of Sweden, situated on Södermalm in the center of Stockholm, is for the moment being completely renovated, with relining of the exhaust ventilation ducts as an important part of the project in order to create better indoor climate and to reduce electrical consumption for fan operation due to previous high duct leakage. The ductwork is originally made of asbestos cement, which presents particular challenges.
Petri Tuomela is the CEO of Tegelhantverk i Stockholm, the company responsible for installing VentilFlex in the building’s ductwork. Mr. Tuomela talks about the challenges:
– The ductwork is from the 1930s and made of asbestos cement where each duct has one or several 90 degree bends on them. With this as starting point we’ve chosen the relining material.
Reline or install new?
Relining the ductwork will provide better air quality and lower energy costs. The alternative would have been to demolish the existing ductwork and to install new spiral metal ducting – something that Petri Tuomela would advise against.
– Concrete or masonry walls enclose the asbestos cement ducts so demolishing them would be very time consuming. The asbestos cement ducts are in some cases left free hanging inside concrete shafts with an imminent risk for the fragile asbestos cement material to break and cause carcinogenic asbestos waste. My opinion is that it is far safer to reline the existing ductwork than installing a new one.
VentilFlex – the material of choice
Tegelhantverk i Stockholm chose VentilFlex, as the material may be installed in any existing ductwork without downsizing the original duct, if specifically not wanted to by choice.
– Before, we’ve worked on many projects by parging flues and vents with ceramic mortar, but parging is not ideal for asbestos cement since it’s thin and fragile. With VentilFlex we found a solution for the different challenges in this particular project, including bends.
The installer tells more
– VentilFlex is available with ready-made bends but can also be easily cut and adjusted by the installer. In addition, VentilFlex is an environmentally friendly material and a good solution from an economic standpoint – both for the installer and the client, says Petri Tuomela. The main diameter we’ve used for apartment ducts is ø125 mm but additionally we’ve used a ø250 mm liner for conveying radon radiation from the bedrock to the outside air. The total amount of installed VentilFlex should sum up to about 1000 meter.
SkorstensFolket Sverige AB supplies flue and vent lining composite materials VentilFlex and FuranFlex to more than 40 installers in Sweden from their head office in Gothenburg.
Tegelhantverk i Stockholm has been hired by General contractor Ovidius Bygg AB for the relining of the ductwork in the parish of Maria Magdalena’s apartment building.