Cooker hood duct exiting near boiler flue.

[Seri]

Hello all, just a really quick question that I can't find the answer to elsewhere. I'm soon going to be installing the new cooker hood and realised that with the planned position for it the ducting will exit the exterior wall quite close to where the current condensing boiler flue exits.

I intend to install gravity vents on the outside of the house to stop any back draft entering and these vents should only really open when the hood is in operation. I'm hoping this will cause enough positive pressure to stop any fume/plume entering back into the house.

Am I right in this? Also, are there minimums for how far another duct/hole should be from the existing boiler flue? Thanks for any and all help.

Seri

[BigWallop]

Never install above, but you can install to the side and below the flue from the boiler, is the normal rule of thumb. Always try to keep them apart by around the 500 to 600 mm mark as well, if you can. If you can't obtain this distance apart, then you need to fit a directional baffle on the vent for the cooker hood so it turns out away from the direction of the boiler flue.

Self closing flaps don't count on extractor ducting when the are fitted to close to boiler flues.

Or, you could lift the end of the cooker hood duct way above the height of the roof and not bother about fitting a fan to it, because of the natural chimney effect it would create.

[Paul Barker]

300mm for a fanned flue unless manufacturers instructions stat otherwise

-- Paul Barker

[Paul Barker]

Sorry 1500mm if vertical, 300mm horisontal. I do beg your pardon.