Small kitchen extractor fan

[Gossamer]

Evening,
I opened a fireplace in my Victorian semi, raised the lintel and put in a cooker and hob.
Surprisingly I'm having trouble finding an extractor to fit into the hole.
Dims are about 230 x 500 mm.
The extractor ducting and electrics are in place.
Cheers.

 

[bobasd]

why not post pics of what you've done and the hole" you refer to (presumably the chimney flue)?
cooker hood extractors require a min of 750mm from gas hob to hood.
there are different diameter outlets in different cooker hood extractors.
what diameter is your in place ducting or liner?

 

[Gossamer]

why not post pics of what you've done and the hole" you refer to (presumably the chimney flue)?
cooker hood extractors require a min of 750mm from gas hob to hood.
there are different diameter outlets in different cooker hood extractors.
what diameter is your in place ducting or liner?

It would help wouldn't it! I've added a few pics.
The ducting is 5''.

 

[bobasd]

a canopy extractor will work and you can easily find one with a 5" dia.
depends on how far you are extracting to a terminal but its good to get a powerful motor - as silent as possible.
i think the lintel was set a little too low but unless you use flaming Woks it should be OK.

has that flue been swept? if not you have to have it swept.
i dont see any ducting?
can you show the ducting?

if you ever do this again use angle iron not timber.

 

[Gossamer]

I've really struggled to find one that would fit.
The distance from hob is perhaps 5cm short max so ok. Bosch came out for a hob warranty issue and said it was ok.
The timber is a temp fix for a bit of ply that stopped muck coming down.
The chimney has been swept.

 

[JohnD]

you could fit something like this

https://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/4_Inch_Fans_Kit/index.html#Kitchen_Fans

but it would have to go up in the chimney void or it will be too close to the hob.

there is a smaller one but it does not seem to have a grease filter, which you need or the duct will get coated with flammable grease which will drip down into your fan and food. This one you can remove the fan and filter to clean. Might be worth keeping a spare set handy.

Or like this, fitted up your void (600mm but other sizes available)

https://www.tlc-direct.co.uk/Products/ELERAHESS60.html

Professional kitchens use steel shutters that close when you have a hob fire to prevent flames setting the duct alight.

 

[foxhole]

You can fit a fan in the chimney and make up a steel plate with cut out to accept grease filters but venting into open chimney will result in condensation running down along with grease build up which could result in a fire.
The distance to hob varies by manufacturer and hob type, the smallest distance I have seen specified was 660mm while the largest was 800mm.So taking one manufacturers guidance could lead to problems .

 

[Gossamer]

you could fit something like this

https://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/4_Inch_Fans_Kit/index.html#Kitchen_Fans

but it would have to go up in the chimney void or it will be too close to the hob.

there is a smaller one but it does not seem to have a grease filter, which you need or the duct will get coated with flammable grease which will drip down into your fan and food. This one you can remove the fan and filter to clean. Might be worth keeping a spare set handy.

Or like this, fitted up your void (600mm but other sizes available)

https://www.tlc-direct.co.uk/Products/ELERAHESS60.html

Professional kitchens use steel shutters that close when you have a hob fire to prevent flames setting the duct alight.

The first one would fit.
So it gets put up the chimney and screwed to the back of it? Then connected to the ducting I've installed.
That would mean the chimney would still be open?

 

[Gossamer]

You can fit a fan in the chimney and make up a steel plate with cut out to accept grease filters but venting into open chimney will result in condensation running down along with grease build up which could result in a fire.
The distance to hob varies by manufacturer and hob type, the smallest distance I have seen specified was 660mm while the largest was 800mm.So taking one manufacturers guidance could lead to problems .

Yes I researched that and put in ducting, didn't like the idea of it going up the chimney, although it has a great draw. If I cook pasta with the windows closed there's no condensation.
The Bosch guy said it was a touch too low but not an issue in practice.

 

[JohnD]

The first one would fit.
So it gets put up the chimney and screwed to the back of it? Then connected to the ducting I've installed.
That would mean the chimney would still be open?

you wouuld need a partition or boxing to separate the chinney from the room. The fan would need to be on the room side with the duct passing through the partition. I'd prefer a non-flammable damp-proof material such as hardiebacker, but there might be a better way.

 

[bobasd]

if you had raised the lintel a few courses higher you would have been able to install a conventional hood extractor, & gained the typical Mfr's dimension between the hob and the appliance.
with what you've got, presuming you are ducting sideways out through the c/breast cheek, you will need as i suggested above - a canopy extractor.

above the canopy extractor you can fit a metal plate or a backer board plate to totally block off the flue - you would then ventilate the upper flue with a vent through any convenient side of the chimney breast.

fwiw: for a swept flue it sure looks sooty, which is not good.

 

[Gossamer]

This is going to be a proper mission! Quite tight up the chimney.
Was hoping to slot in a canopy unit with light etc.

PS. The flue was swept, but yes its grotty and some muck does come down during high winds..... Not much, just a few chunks.

 

[bobasd]

"slot the canopy" in what?

i dont understand your problem with the canopy ext. - they most all have lights and control panels?
the face of the canopy is level with the bottom of the lintel while the canopy itself is set in a frame or plate cutout - i thiught you understood this?
above the appliance you must blank off the flue.

you've not shown the ducting or the canopy thats been chosen?

 

[Gossamer]

Ok I *think* I'm being a bit dim.
So I close the chimney off above the extractor and ventilate through the side of the chimney.
The first unit shown is secured to the rear 'wall' inside the chimney, above where the canopy goes, and attaches to the ducting.
Then a canopy goes flush below which contains the various filters and lights.
So there's a void between the canopy and the chimney seal where the extractor unit sits against the 'wall', which is just where air is pulled through to be extracted.
I don't seem to be able to find canopy's on their own as such. They seem to be integrated with an extractor and are too big.

 

[foxhole]

Minimum dimensions usually around 500x465 do unlikely to fit .