VENTILATION CHIMNEYS!
Fully insulated exhaust and intake chimenys. Outside material HDPE, Inside material HDPE. In between: 50mm PU-insulation. Especially suitable in colder climatic zones as the insulation avoids condensation and freezing up of condensation. Tried and tested in Siberia as well as in Italy.
Available for now in 2 diameters: 570mm and 650mm. Therefore most standard available chimney fans will fit.
All necessary accessories are available. E.g. wind rind, wind cone, rain hood with special corona reducing airflow restriction, inflow rings, dampers, butterfly valves and standard roof sheets for closing up the roof from the outside.