FT System Updated: 2019-01-25

Supply and exhaust air ventilation (FT) 
An exhaust duct fan is installed, e.g. above the cooker hood (spice rack duct fan IFK), on the roof (roof fans TKC, TKS, TKV) or in the attic (insulated duct fan IRE).
Ducts and fresh air intakes must be installed, and the increased ventilation may lead to increased heating costs.