Central heating flueing
A central heating unit can be installed in a roof space, under the floor, outside, or in a garage. Internal units must be flued to the outside. Placement will depend on the design of the house.
The ductwork is installed within the ceiling cavity, under the floor or a combination of both. It is also possible to run between floors within the joist cavity or through pre-prepared bulkheads or lowered ceilings.
Air for combustion must be taken from outside via permanent fixed ventilation grills and must be kept completely separate from the return air. The return air must be sealed from the cavity containing the heater to eliminate any adverse effect on the flue system, or the ventilation and combustion airflow to the central heating unit, or any other appliance.