Ventilation mountingDuct systemLegislationATTENTIONAll work must be carried out by qualified personnel and in accordance with applicable legislationand regulations.DuctsThere are two systems for transporting air round the building.Spiral tubesSpiral tubes are metal ducts which are cut to size with an angle grinder, screwed together with bendsand manifolds and laid out in accordance with the working drawing. The duct pipes are typically laid atthe rafter ends and fixed with perforated band or suspended with suspension band. Avoid unnecessarybends in the ducting.To avoid noise transmission, where sound is transmitted from room to room, a sound damper must bemounted in each room.The ducts must be insulated to avoid heat loss and condensation. In some cases this can be avoided ifthe ducts are led through the ordinary insulation or inside the climate screen.NilAIR tubesNilAIR tubes are a flexible system which is easy to mount. The tubes are easily cut to size with a hobbyknife and laid according to the working drawing without use of bends and manifolds. A manifold box isinstalled after the unit and the tubes run from this out to the various rooms.With NilAIR tubes it is unnecessary to mount sound dampers in each room, as there is no risk of noisetransmission.If the tubes are led outside the climate screen they must be insulated to avoid heat loss andcondensation. This is easier than with spiral tubing, as NilAIR tubes are easier to lead through ordinaryinsulation.NilAIR tubes are more flexible than spiral tubing and can therefore be laid in places where ordinaryspiral tubing would be impossible.UnitNilan recommends mounting a flexible connection between the unit and the duct system.This is to avoid oscillations from the unit being transmitted to the duct system, but also to ease futureservicing where it is necessary to move the unit.Nilan offers flexible silicing, which, apart from providing a flexible connection between the unit and theduct system, also dampen the passage of sound from the unit to the duct system.Flexible silencing are insulated for condensation, but it may be necessary to insulate them further tomeet local requirements for duct system insulation.56