3 - 5%Max 3 mtENGLISHIt is mandatory to use airtight pipes.CHIMNEYIn addition to the general requirements, the chimneys for releasing combustion products into the atmosphere must: operate under negative pressure (operation under positive pressure is not allowed); have a preferably circular internal section; square or rectangular sections must have rounded corners with a radius of noless than 20 mm (hydraulically equivalent sections may be used, as long as the ratio between the longer side and the shorterside of the rectangle, which circumscribes the section, is in any case no greater than 1.5); be designed for fumes be designed for fumes expulsion; be predominantly vertical and have no narrowing along their entire length; have no more than two direction changes with a slope angle no greater than 45°; be fitted with, in the event of operating in damp conditions, a device for reflux drainage (condensation, rainwater);Ducted systemA ducted system can be installed with one or more ducts, operating only with negative pressure with respect to the environment.The flexible hose compliant with UNI EN 1856-2, with T400-G characteristics, meets the requirements.CHIMNEY CAPSThe chimney caps must meet the following requirements: they must have a useful outlet section no less than double of that of the chimney/ducted system on which it is installed; they must be adapted in order to prevent the penetration of rain and snow in the chimney/ducted system; they must be built so that, in the event of winds coming from all directions and from any angle, the expulsion of combustionproducts is in any case ensured; they must be free from mechanical intake aids."T" fitting withinspectionplugSteel plate,airtightInsulated "T"fitting withinspection plugProtection from rainand windProtection from rainand wind"T" fitting withinspection plugEXAMPLES OF CORRECT CONNECTION TO THE CHIMNEY55
