A conventional flue (sometimes called an openflue appliance) uses a flue continuously rising from the top of the cooker and terminating above the highest part of the roof.
Conventional Flue Options
Older properties may have a convenient chimney built of stone or brick which can be used for this purpose, providing that the inside is lined with an acid resistant material.
Sometimes, when there is no masonry chimney, the flue-pipe from the cooker can be taken all the way up using special prefabricated flue systems. These consist of a twin-wall pipe and are usually manufactured from stainless steel.
The type of material used depends on the fuel type and cooker model, as does the flue diameter. This can range from 125 mm (5″) for some gas-fired models to 200 mm (8″) for a multifuel or woodburning cooker. Generally, models providing central heating as well as cooking require larger flues.
A single wall pipe connects between the cooker and the main chimney, preferably made of cast iron, as this matches the appearance of the cooker and helps to reduce noise levels. The flue-way inside the main chimney should normally be one size larger in diameter than the connecting pipe.
Normally the flue rises continually with no horizontal stretches. Some solid fuel cookers (not oil or gas) can connect into a masonry chimney from the rear, with a maximum 150 mm horizontal pipe.
Appliances must not share a flue, although there can of course be several separate flues travelling together inside a traditional chimney. Conventional flued cookers can be sited on internal or external walls within the property as convenient.
Other Flue Types