Island Downdraft Extraction

[mhearne]

I'm starting a new build and plan to install a downdraft hob on the island. To extract to the outside (~3m away), I'll need to bring a 220x90mm duct or 150mm diameter duct under the kitchen floor to the outside.

What's the best way to exit the outer wall (150mm cavity)? I guess I either bring it up inside (behind some kitchen cupboards) or bring it up upside?

House will be air tight so will have to consider something like a thermobox I reckon.

Any suggestions/help appreciated

 

[kitfit1]

My suggestion is don't use a downdraft extractor. If this is a new build you can design the build so that the joists run the right way to enable you to use an overhead island extractor in the first place. It will do a hundred times better a job of actually extracting than the most expensive downdraft extractor could ever dream of.
Just make shure the design has room for a 5inch drainage pipe from an outside wall to the hood with as few or no bends in it as possible.

 

[mhearne]

The kitchen ceiling is 3m high so downdraft is really the only way to have a hob in the island.

 

[kitfit1]

The kitchen ceiling is 3m high so downdraft is really the only way to have a hob in the island.

No it isn't. Every island cooker hood that we can buy here is made in Europe and all of them have a telescopic design that can easily manage a 3m ceiling height. The minimum height above a gas hob is 750mm, i've never fitted an island hood that wouldn't reach 3m yet allowing for the 750mm in the first place.

 

[wh100]

New to this community not trying to steal this post just cannot see how to post my own . I have a elica adagio bought new , No problems fitting but there is no suction ? vented outside blows powerful onto driveway all functions work . has settings 1to4 does not pulling anything from hob , heald a piece of paper next to it nothing ? any ideas much appreciated .

 

[Hausfix]

New to this community not trying to steal this post just cannot see how to post my own . I have a elica adagio bought new , No problems fitting but there is no suction ? vented outside blows powerful onto driveway all functions work . has settings 1to4 does not pulling anything from hob , heald a piece of paper next to it nothing ? any ideas much appreciated .

Don’t worry about hijacking this post, it died three years ago..
With regard to your Elica, if you can feel the air flowing out of the exhaust vent, the only way it can be circulating is via the hob inlet unless the fan motor housing is not screwed to the main extractor body under the cabinet or the blanking panel is missing on the other side of the motor housing (this has to be in place if you have switched the motor housing from front to back.
If you smoke or know someone who does, get a lit cigarette and hold it near the extractor inlet and see if the smoke is pulled in when set to the highest setting, if not, take a look underneath and waft the smoke around the extractor body and motor to see if it is drawn in down there somewhere.
I’ve fitted numerous downover the years, and found them all to be pretty useless, nice idea, but simply nowhere near as effective as overhead extractors.