Kitchen extract - Ever used/fitted/made a downdraught one?

[markocosic]

Kitchen extractors...

 

 

Anybody used a downdraught unit? Fitted one? DIY made one? 

 

 

This looks attractive as a concept:

 

 

 

 

Do they actually work?

 

 

 

We have a cathedral ceiling to the kitchen/living space and would like a clear wall (1) for aesthetic reasons and (2) for cleanliness.

 

I'm thinking of making one - perhaps the same thing but with the extract "grille" wall mounted into the splashback with a duct dropping down the service void.

 

Hob will be electric induction.

 

 

 

Why?

 

I hate cleaning the things and she hates how they look. We have the IKEA 'underwerk' unit in the current house.

 

It's relatively invisible (hidden in one cupboard and boiler hidden in the matching cupboard); it doesn't block your sightline and you don't smash your head on it (we're both 6'); and it can extract steam.

 

Unfortunately the duct runs upwards before existing the wall and it drips condensation back when not in use. For example condensed grease from a previous steak fry gets softened by steam from a subsequent stew and will ooze back onto the worktop. (it has a mesh grease filter but it isn't enough) Or you get grease / tomato splashes up the wall and on the underside of the cooker hood that are a pain to clean. (you could say that we're clumsy) The buttons on the bottom of that...get sticky.  That off white cupboard...also gets stickier and less white rather quicker between cleans than we'd like.

 

 

It feels like a downdraught unit or a "letterbox" in the wall; with a clear wall and worktop; might extract the steam and make clearing up the grease/tomato/flying spaghetti from the flat surfaces easier.

 

 

 

[Onoff]

A few on here have Bora downdraft extractors I think. Search "Bora".

[Jenni]

Hoping to see responses to this too, sounds very similar to what I hope to achieve.

 

My thoughts so far are to possibly buy a pop-up downdraft extractor, and rather than use the lifting function, Plumb the extract unit into a self created opening in the wall. 

[markocosic]

 

A few threads.

 

 

Consensus appears to be Novy, Bora, Gaggenau hobs (if you have to ask you can't afford)

 

Consensus also appears to be in-hob extract better than pop-up extract (surprising; but could be as much to do with crummy mechanisms as the fundamentals of extracting at height?)

 

 

IKEA are starting to do this style. Still rather spendy and Noisy as all heck though:

 

https://www.ikea.com/gb/en/p/foerdelaktig-induction-hob-integrated-extractor-ikea-700-black-50449403/

 

If you wanted to DIY an in-worktop extract you could add a pair of smaller hobs. It'd probably be a pig to clean though and probably not save you anything once you'd finished faffing.

 

https://www.ikea.com/gb/en/p/vaelbildad-induction-hob-ikea-300-black-20467592/

 

Probably time to hold this thought for a while.

[joth]

12 hours ago, markocosic said:

Consensus also appears to be in-hob extract better than pop-up extract (surprising; but could be as much to do with crummy mechanisms as the fundamentals of extracting at height?)

The in-hob extractors are typically equidistant from all four "rings" on the hob, whereas the pop-up ones have to be on the far side of the hob, making them too far from the front 2 rings thus much less effective

 

One more thing to add:-

If doing an airtight build and/or with MVHR, you should plan for an internally recirculating downdraft, not one ducted to extract to outside.

 

 

[markocosic]

Recirculation is still up for debate.

 

 

I'm sceptical because life experience of recirculation to date has been awful (shitty flats with grease filled asthmatic mouse recirculation hoods) whereas extract hoods have been decent (at extracting anyhow). Too sceptical to rely purely on recirc.

 

 

It's a newbuild. It's tight and it's having MVHR. Hob would be going to the left of the bucket. It could also go in front of the window to the left but I fear that would be insanity unless you like drawing on grease or you had a pop-up downdraught extractor / splash guard behind the hob. (such as http://www.hobcoversdirect.co.uk/index.html very practical but icky style)

 

 

 

The MVHR has a bypass on the extract. It's a proper* bypass with motorised shutters to close flow through the core and a motorised bypass to go around it. By default it opens when the indoor temperature rises too much. It can also be controlled manually. Boost flowrate is 500 m3/hr at 100 Pa drop.

 

It is very tempting to pipe the extract the hood into this. "Low" hob extract = boost and bypass the MVHR (only) and extracts steam in near silence. "High" hob extract boosts and bypasses the MVHR and adds the hob extractor fan in series to counter the duct / filter pressure drop. "No" hob extract is also an option if it's only steam. (allow the regular MVHR to clear the moisture)

 

Or extract to outdoors. Or setup as a recirculation hob with the option to shove it through the wall later.

 

It wouldn't be done for energy saving. (bypassed MVHR is the same as pure extract) It'd be for noise as much as anything else.

 

 

Extracting from the oven is also up for debate. (if you roast meat or you roast potatoes in fat etc then fan ovens vent grease) 

 

Perhaps we should extract into the oven then bake all the grease out occasionally...

 

https://www.berbel.de/dunstabzuege/zubehoer/umluft-zubehoer/umluftfilter-permalyt/

 

 

 

 

 

*Another MVHR unit that I bought had a joke bypass. There was a tiny flap next to the core with a wax filled actuator that would - slowly - open as the temperature rose. No blanking of the core. Just a flap that in theory moved with heat and in theory bypassed some air so that they could tick the box for having a summer bypass. The same absolute jokers (Brookvent) also refused to sell spare parts so the entire MVHR unit needs to be replaced if anything fails.

[joth]

2 hours ago, markocosic said:

I'm sceptical because life experience of recirculation to date has been awful (shitty flats with grease filled asthmatic mouse recirculation hoods) whereas extract hoods have been decent (at extracting anyhow). Too sceptical to rely purely on recirc.

 

I was skeptical too, but the Bora Pure X with recirc has greatly exceeded expectations. It has a built in dishwasherable filter that does really well, I've never yet found any grease on the under plinth gap in expels air through. (It blows out across porcelain  tiles and we have a weekly house cleaner, so maybe they just keep on top of mopping it well enough we have never seen any build up). YMMV!

 

If you have a plan to extract to outside with an airtight damper when not in use, and solve the issue of where the inlet air supply comes from to balance it, then fair enough, but that sounds a lot of extra cost and faff where the recirc would work.

 

 

Edited September 20, 2021 by joth

[Jenni]

On 20/09/2021 at 11:09, joth said:

The in-hob extractors are typically equidistant from all four "rings" on the hob, whereas the pop-up ones have to be on the far side of the hob, making them too far from the front 2 rings thus much less effective

 

 

Paired with a linear hob should be good I think. 

 

Quite apart from the price of Bora et al, they look to me like a grotty kind of mess magnet that's hard to keep clean, hence the desire to have extract on the wall.