The III FU system

The III FU system is a double-walled, thermally insulated, exhaust gas system that is made from stainless steel and it is suitable for all standard fireplaces that operate with negative pressure in dry and moist (condensing) conditions. The system is used for boilers with exhaust temperatures of up to 600°C and therefore it is suitable for solid fuels, EL heating oil and gas.

The system is especially suitable for erecting on external walls. A thermally insulating layer of 34 mm thick mineral wool that is placed between the inner and outer shells ensures the necessary thermal insulation and therefore the system is classified in the Thermal Insulating Group IIa. The III FU system is also insensitive to expansion and contraction, even in the case of drastically oscillating temperatures.

The system is manufactured with diameters ranging from 80 mm to 600 mm and the thin-walled inner sleeve allows it to reach the temperature of the flue gas quickly; it also ensures low formation of condensation and high resistance to draughts.