Kitchen extractor duct running under suspended floor and back up. Drawing attached.

[ToastyToes]

Checked out a demo and it was computer graphic, not a real hob in a real kitchen, doubt it would perform very well in the real world, and can imagine a mess if a pan boils over or is spilt into the fan.

Live Demo:

The fan has a drip tray for spillages down it. Induction hobs are fantastic for boil overs as they just need a wipe with a cloth.

 

[Ian H]

I’d he cooking that heavier than air dry ice stuff off Top of the Pops?

 

[SpecialK]

Thats not steam from water.. and probably something heavy than air?

 

[ToastyToes]

I’d he cooking that heavier than air dry ice stuff off Top of the Pops?

Thats not steam from water.. and probably something heavy than air?

There are lots of actual cooking ones on youtube if you're interested to see the performance of them.

 

[foxhole]

That’s dry ice, heavier than air , still doesn’t show what happens when you spill a pan of oil down it.

 

[jj4091]

If that is the type of hob you are going to instal then search for a user/installation guide/instructions & it should tell you how to vent it away from your island.It may not be suitable for that situation but have to be next to an external wall.

 

[Matdar]

Just wondering if there could be potential problems with running the kitchen extractor from the island under the suspended floor across the kitchen, back up through the floor and then out the wall?

Drawing below - The ducting is drawn in red.

View attachment 164521

I am facing the same challenge - so really interested to know what you did in the end.
Did it work out?
Mstt

 

[chirpychippy]

Yes you can duct in the floor void, use 220 x 90 rigid ducting and lay it on the ground, I.e dont hang it off of the joists as ducting can vibrate when in use.

You can buy a square to round adaptor for this type of ducting to duct through the house wall through a 6 inch core hole, the core hole has to be 6 inch due to the distance between the hob and the exterior wall. If you use a small duct the hob will be noisy and you will invalidate its warranty.

I presume the hob is a downdraft, you may have to buy product specific ducting to get from the hob to the off the shelf ducting.

If you let me know the manufacturer I may be able to tell you what you need, its a bit of a minefield.

 

[Matdar]

Thanks for the response.
It is a downdraft age hob and the ducting kit is 220x90.
However the floor is block and beam with joists and insulation board on top. I can run a 60 mm duct between the joists and the blocks but 90 would mean notching the joists. That might be ok as I can add support to the joist either side of the ducting. But I had hoped to be able to use a reducer to go from 90 to 60 before the ducting went under the floor. But from what you say that might be a problem. The ducting would run for 3m.
I might have to fallback to a ceiling mounted extractor fan but that won’t be as effective as the down draft or as aesthetic :-/

 

[blup]

Warm air rises, just core the wall and put a suitable extractor in

 

[freddiemercurystwin]

Warm air rises, just core the wall and put a suitable extractor in

It's in a 'well thought out' island.

 

[chirpychippy]

Thanks for the response.
It is a downdraft age hob and the ducting kit is 220x90.
However the floor is block and beam with joists and insulation board on top. I can run a 60 mm duct between the joists and the blocks but 90 would mean notching the joists. That might be ok as I can add support to the joist either side of the ducting. But I had hoped to be able to use a reducer to go from 90 to 60 before the ducting went under the floor. But from what you say that might be a problem. The ducting would run for 3m.
I might have to fallback to a ceiling mounted extractor fan but that won’t be as effective as the down draft or as aesthetic :-/

You can gone from 90 to 204 x 60 but the downdraft may not be as effective and it may be noisier.

You can buy a square to round which goes from 90 to a 6 inch round spigot and you can buy a 204 x 60 rectangular to round 6 inch spigot, so you can connect the manufacturers duct to the off the shelf duct with 6 inch flexi.

Personally I wouldn't connect the 204x60 rectangular to round directly to the 204 x 60 flat channel preferring to create better airflow with 90 degree vertical bend.

Go on TLC's website, they cover all of the components for a variety of conundrum.

If push comes to shove put it on recirculation kit and put an extractor in the wall, you'll still have the WOW of steam tunnelling into the downdraft it'll just be leaving via a different route.