I'm upgrading my kitchen extraction from circulating through a filter to ducting to the outside. My issue is the proximity of the exit point of the extractor to the existing combi boiler flue.
It will sit about 300 mm directly above the flue. I have looked at the regs and as far as I can tell 300 mm is fine if off to either side but I think siting the ducting exit point above or below a flue requires a greater separation (600mm or even 1200mm). Can anyone confirm as I obviously I need to avoid any fumes coming back into the kitchen.
I should add that the extractor hood will have 150mm round ducting going vertically for approx 1 metre, converting to 220mm x 90mm flat ducting horizontally for 2 m until it reaches the wall at which point I can convert back to 150mm round to exit through the wall, or more likely continue the flat duct through the wall and terminating in a grill outside.
I have a jointing piece with a 'damper', a hinged plastic flap intended to prevent cold air coming into the house, which will be fitted along the 2 m flat run. There is a possibility of a vent grill with another damper on the outside. These dampers are very simple affairs, not completely airtight and in any case could potentially jam in an open position so cannot be counted on to prevent gasses reentering the property.
As it stands I'm looking at a rather eccentric solution involving two 90 deg elbows on the flat ducting outside to snake away and to the side of the flu. I think it'll work but look awful.
The alternative might be to mess about with the boiler flue. Its an old vaillant turbo max VUW 242/2.5. At present the flue comes out of the top of the boiler and immediately turns to the side and out through the wall. Is there a clever way of adding some elbows and turning it into a vertical flue or turning it to the side of its current position?
I've been in touch with vaillant tech support who were well meaning but vague. Of course I want to do this safely and thought I'd pick some brains on here first.
It will sit about 300 mm directly above the flue. I have looked at the regs and as far as I can tell 300 mm is fine if off to either side but I think siting the ducting exit point above or below a flue requires a greater separation (600mm or even 1200mm). Can anyone confirm as I obviously I need to avoid any fumes coming back into the kitchen.
I should add that the extractor hood will have 150mm round ducting going vertically for approx 1 metre, converting to 220mm x 90mm flat ducting horizontally for 2 m until it reaches the wall at which point I can convert back to 150mm round to exit through the wall, or more likely continue the flat duct through the wall and terminating in a grill outside.
I have a jointing piece with a 'damper', a hinged plastic flap intended to prevent cold air coming into the house, which will be fitted along the 2 m flat run. There is a possibility of a vent grill with another damper on the outside. These dampers are very simple affairs, not completely airtight and in any case could potentially jam in an open position so cannot be counted on to prevent gasses reentering the property.
As it stands I'm looking at a rather eccentric solution involving two 90 deg elbows on the flat ducting outside to snake away and to the side of the flu. I think it'll work but look awful.
The alternative might be to mess about with the boiler flue. Its an old vaillant turbo max VUW 242/2.5. At present the flue comes out of the top of the boiler and immediately turns to the side and out through the wall. Is there a clever way of adding some elbows and turning it into a vertical flue or turning it to the side of its current position?
I've been in touch with vaillant tech support who were well meaning but vague. Of course I want to do this safely and thought I'd pick some brains on here first.
P1070371