Smitsair B.V. roof-cowling products are designed to be rainproof covers for roof ducting in both natural and mechanical building ventilation. The roof cowls are available in various models. We also supply excellent solutions for pitched roofs. You may choose from any RAL colour as well, as we have our own powder-coating department.
For information relating to the dilution factor (NEN1087) between different roof cowls, read article: dilution factor (NL)