Britannia Duct/910 Houseware chimney extension

1 metre flat channel To obtain the best possible extraction performance use 150mm diameter ducting. Wherever possible utilise rigid circular pipe or ‘Mega Duct’ ducting – both types are available via your Britannia dealer. Where possible, do not use expanding concertina type ducting as this is not smooth on the interior and can cause air flow restrictions. Do not use ducting that has a smaller diameter than 150mm as this will reduce extraction rates and can increase noise levels.