Hob Extractor fan

[MrFish]

Has anyone fitted an extractor fan above their hob? I want a reliable way of removing unwanted cooking smells and reducing the risk of condensation from boiling water. I don't really mind if it is 12v or 240ac.

[cuthound]

My boat came with one already fitted. It uses a 12 volt fan extracting through a roof mounted mushroom vent and works well.

Edited January 28, 2023 by cuthound
Clarification

[Slim]

2 minutes ago, cuthound said:

My boat came with one already fitted. It uses a 12 volt fan extracting through a roof mounted mushroom vent and works well.

12v computer fan (available on e bay) wired into a miniature rocker switch and fed off a galley light or nearby light supply. That's my set up. I also have one over the bathroom hand basin and another in the shower cubicle. They can be fixed into the mushroom upstands with a dab of silicone. You may need to file the extreme corners off of the fan bodies.

[matty40s]

I built my own from 2 heavy duty dirty air fans as there was nothing on the market to fit the space between the top cupboards.

[MrFish]

3 minutes ago, Slim said:

12v computer fan (available on e bay) wired into a miniature rocker switch and fed off a galley light or nearby light supply. That's my set up. I also have one over the bathroom hand basin and another in the shower cubicle. They can be fixed into the mushroom upstands with a dab of silicone. You may need to file the extreme corners off of the fan bodies.

Is that the smaller fans or will a 120mm fit?

 

[PeterF]

We have one of these in the galley mushroom vent and one in the shower room.

 

12V light and fan

[Slim]

2 hours ago, MrFish said:

Is that the smaller fans or will a 120mm fit?

 

Depends upon the dimensions of your mushroom vent upstands.

[Russ9294]

On 28/01/2023 at 17:24, Slim said:

12v computer fan (available on e bay) wired into a miniature rocker switch and fed off a galley light or nearby light supply. That's my set up. I also have one over the bathroom hand basin and another in the shower cubicle. They can be fixed into the mushroom upstands with a dab of silicone. You may need to file the extreme corners off of the fan bodies.

Hi did you put inline fuse from light to fan

[TandC]

I have a 12v computer fan tucked up in the mushroom vent in the galley area - it isn't directly above the hob and isn't sealed in anyway, literally just poked up there. I was very sceptical it would do anything but it does gather a surprising amount of grease so it must be moving air.  It's better than nothing.

 

For my new boat, i've been looking at better options. 

 

There are slimline 12v cooker hoods made for the motor home market - they're bloody expensive - and i don't think they extract, they recirculate through grease traps I think.  https://www.amazon.co.uk/Dometic-CK2000-Cooker-Extractor-Halogen/dp/B002BW6CIE/ref=asc_df_B002BW6CIE/?tag=googshopuk-21&linkCode=df0&hvadid=309862953042&hvpos=&hvnetw=g&hvrand=4056514625113343313&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006839&hvtargid=pla-562856114140&psc=1&th=1&psc=1 

 

As my new boat is 10ft wide, the cooker will be orientated away from the wall, more in the centre.  This means there is head room above and I have sourced a 240v integrated extractor fan for building into a small cupboard over the hob.  I saw a lot of the widebeam boats at Crick had these installed - various brands etc - this one i got on facebook new for £40 so worth a punt.

 

https://business.currys.co.uk/catalogue/kitchen-domestic-appliances/cooking/cooker-hoods/zanussi-zhg51251g-integrated-cooker-hood-stainless-steel/B246672B

 

I may need to use a short section of flat duct to extract through a mushroom vent located on the centreline of the roof as the hob will be a bit off-centre.  Not got to it yet... it may not be feasible.

 

Hope that helps - three options. 

 

[IanD]

1 hour ago, TandC said:

I have a 12v computer fan tucked up in the mushroom vent in the galley area - it isn't directly above the hob and isn't sealed in anyway, literally just poked up there. I was very sceptical it would do anything but it does gather a surprising amount of grease so it must be moving air.  It's better than nothing.

 

For my new boat, i've been looking at better options. 

 

There are slimline 12v cooker hoods made for the motor home market - they're bloody expensive - and i don't think they extract, they recirculate through grease traps I think.  https://www.amazon.co.uk/Dometic-CK2000-Cooker-Extractor-Halogen/dp/B002BW6CIE/ref=asc_df_B002BW6CIE/?tag=googshopuk-21&linkCode=df0&hvadid=309862953042&hvpos=&hvnetw=g&hvrand=4056514625113343313&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006839&hvtargid=pla-562856114140&psc=1&th=1&psc=1 

 

As my new boat is 10ft wide, the cooker will be orientated away from the wall, more in the centre.  This means there is head room above and I have sourced a 240v integrated extractor fan for building into a small cupboard over the hob.  I saw a lot of the widebeam boats at Crick had these installed - various brands etc - this one i got on facebook new for £40 so worth a punt.

 

https://business.currys.co.uk/catalogue/kitchen-domestic-appliances/cooking/cooker-hoods/zanussi-zhg51251g-integrated-cooker-hood-stainless-steel/B246672B

 

I may need to use a short section of flat duct to extract through a mushroom vent located on the centreline of the roof as the hob will be a bit off-centre.  Not got to it yet... it may not be feasible.

 

Hope that helps - three options. 

 

The extractor fan / roof mushroom option is what I went for after a lot of discussion with Ricky at Finesse -- from experience recirculating fans aren't much use, especially if you're doing things like frying bacon. The one we used was a fairly small one from CDA which cost about £75 IIRC, it's built into a box over the hob with a big mushroom vent through the roof and a small length of flat ducting connecting them up, in my case because the vent would otherwise be too close to the handrail.

 

https://www.cda.co.uk/extractors/integrated-extractors/CCA52WH/

 

Edited July 24, 2023 by IanD

[pearley]

I had the builders fit a low profile vent in the roof above the hob and continue the line of overhead cupboards with a void above the hob. The fitted a small car radiator fan on a ply board with a resistor to give 2 speeds.

[Roberto Conigliaro]

On 28/01/2023 at 17:24, Slim said:

12v computer fan (available on e bay) wired into a miniature rocker switch and fed off a galley light or nearby light supply. That's my set up. I also have one over the bathroom hand basin and another in the shower cubicle. They can be fixed into the mushroom upstands with a dab of silicone. You may need to file the extreme corners off of the fan bodies.

Hi, I am planning to do the same thing - getting a computer fan wired to my 12v led light and use the same switch to turn the light and fan on at the same time, I was wondering what's the best way to wire the cables together? do I need a splitter? 

 

attached the photo of the light which will feed the 12v to the the fan and a link of the fan I have bought 

 

I am new to electronics so any advice will be greatly appreciated  

 

https://www.amazon.co.uk/gp/product/B07C5LRQD3/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

 

[Jen-in-Wellies]

Welcome to the forum. To work the fan from the same switch as the light, one wire needs connecting to the left hand terminal of the switch as shown in the picture, as this is the side that is turned on and off by the switch. The other fan wire needs to be connected to the blue wire. There is little of this wire visible in the light fitting, so unscrew the fitting and see what the blue wire attaches to in the ceiling space and use that. A photo will help us suggest where. If the fan runs backwards, swap the wires round.

Various ways of making the connections. Wago three way connectors are easy to use.

[TandC]

Putting Jen's above into a picture... 

 

Wago connectors - those little orange levers flick up, you push your stripped cable into the hole and snap the lever down - these ones effectively join the cables together within the housing, creating a connection across them all. Much easier than the old screw "chocolate block" terminals.  They are about the size of a double pencil sharpener (what a strange thing to come to mind...) so you have to find somewhere to tuck them away.  

 

So one Wago is for the negative.  One is for the switched positive. You need to take a little piece of cable from the switch, into the Wago. Then another piece of cable into the LED, and another cable goes off to the fan.   Ditto on the negative.

 

You don't have much of the blue negative cable to play with so I expect you will need to take all the light fitting out, lengthen all the cables and tuck everything away under it - up inside the ceiling void. 

 

 

[ditchcrawler]

I would suggest you will probably find a connector behind the light fitting that the blue wire is connected to so you could use that.

Just now, ditchcrawler said:

I would suggest you will probably find a connector behind the light fitting that the blue wire is connected to so you could use that.

 

[Roberto Conigliaro]

Thanks so much you both, much more clear now - here what's behind the light fitting: so if I understood well, instead of the clear plastic connector on the right attached to the blue cable, I will fit one the Wago splitter, and the other one will be fitted after the switch.

 

 

[ditchcrawler]

11 minutes ago, Roberto Conigliaro said:

Thanks so much you both, much more clear now - here what's behind the light fitting: so if I understood well, instead of the clear plastic connector on the right attached to the blue cable, I will fit one the Wago splitter, and the other one will be fitted after the switch.

 

 

While you have it down replace both those screw connectors with Wago's

[Francis Herne]

I was wondering if an extractor fan would be a hazard with the stove lit - on my small boat they're in the same room.

 

Wouldn't overpower the draught of a really hot fire but I fear it might with a few coals banked up.

 

Might be a case of "so don't use it in that case"...

[ditchcrawler]

5 minutes ago, Francis Herne said:

I was wondering if an extractor fan would be a hazard with the stove lit - on my small boat they're in the same room.

 

Wouldn't overpower the draught of a really hot fire but I fear it might with a few coals banked up.

 

Might be a case of "so don't use it in that case"...

I thought it was over a cooker

[Francis Herne]

7 minutes ago, ditchcrawler said:

I thought it was over a cooker

It would be, but I'm not sure how much negative pressure an extractor fan generates across the whole cabin. My stove is about 8ft away. Maybe not an issue with the mandated low-level vents fairly nearby.

Edited October 30, 2023 by Francis Herne

[TandC]

21 minutes ago, Roberto Conigliaro said:

Thanks so much you both, much more clear now - here what's behind the light fitting: so if I understood well, instead of the clear plastic connector on the right attached to the blue cable, I will fit one the Wago splitter, and the other one will be fitted after the switch.

 

 

Indeed - the brown in the ceiling is your positive -  so that goes into your switch to provide the permanent on supply.  Then you need to add some cable after the switch into the positive Wago. You'll need to come back off the switch back into the ceiling void so you've somewhere to put it.   That Wago will only be live when the switch is thrown.  Then from that, you'll have two brown - one going back through to the LED, one off in your ceiling void to the fan.  With the blue neutral it's easier as no switch - just get the three connected. 

[Roberto Conigliaro]

16 minutes ago, ditchcrawler said:

While you have it down replace both those screw connectors with Wago's

Thanks for the tip Brian, yes will do that.

2 minutes ago, TandC said:

Indeed - the brown in the ceiling is your positive -  so that goes into your switch to provide the permanent on supply.  Then you need to add some cable after the switch into the positive Wago. You'll need to come back off the switch back into the ceiling void so you've somewhere to put it.   That Wago will only be live when the switch is thrown.  Then from that, you'll have two brown - one going back through to the LED, one off in your ceiling void to the fan.  With the blue neutral it's easier as no switch - just get the three connected. 

Makes a lot of sense, thanks so much

12 minutes ago, ditchcrawler said:

I thought it was over a cooker

Yes, it will fitted near the cooker 

[Jen-in-Wellies]

52 minutes ago, Francis Herne said:

I was wondering if an extractor fan would be a hazard with the stove lit - on my small boat they're in the same room.

 

Wouldn't overpower the draught of a really hot fire but I fear it might with a few coals banked up.

 

Might be a case of "so don't use it in that case"...

If you've got lots of top and bottom ventilation, as per BSS advisory calculations, I doubt it would be a problem. That's based on the oxygen consumption from people, flued items, like heating stoves and unflued items, like cookers.