Externally vented cooker hood?

WIAWSNB

What's behind that square external grille - a round 150mm pipe? 

Anyhoo, a solution could be: (1) round to rect duct adaptor, (2) a length of rect duct, 206x60, (3) an elbow, (4) a brick vent (4). There are cover plates to fit around that existing wall exit point, such as (5).

All of this could be simply StixAll'd to the wall with a few blobs, and painted whatever colour is best

One thing I would definitely do before assembly is to punch/drill/heat through a small hole (~6mm) from the inside, through the lowest bottom part of the duct adaptor, so that any condensation that forms in the ext vertical duct drips out harmlessly. 

1) https://www.screwfix.com/p/manrose-round-to-rectangular-flat-channel-appliance-connector-elbow-90-bend-grey-204mm/50534

2) https://www.screwfix.com/p/manrose-204-x-60mm-flat-channel-1m/59769

3) https://www.screwfix.com/p/manrose-vertical-90-bend-white-204mm/85490

4) Ext vent cover: https://www.screwfix.com/p/manrose-air-brick-vent-white-204mm-x-60mm/50089

5) Cover: https://www.screwfix.com/p/manrose-round-wall-plate-white-120mm/83840

Or, a flatter version, but is bound to be more restrictive: https://www.screwfix.com/p/manrose-rectangular-flat-channel-vertical-90-bend-white-225mm/78560

blackstar

Yes thank you both for your help. It cost us £2k to get the kitchen ceiling plastered and the cooker hood externally vented. As well as 3 full days if disruption.

Yes it is a 150m pipe. Half goes under ceiling and the other half that goes out wall is boxed in and plastered over. 

So was very dissapointed when he said the wind blows the smell into his bedroom as the wind always blows for some reason from our house to his. He has his bedroom windows open but the vent is just above our downstairs kitchen window. He said it blows into all his windows, upstairs and down stairs. 

No he wasn't grateful for what we have done si far. He did say though that now the smell doesn't stay in his bedroom 24 hours a day it only smells when we cook and then goes away. He keeps all his windows open 247. 

We do smell neighbours cooking coming into our windows from the house to the other side. Doesnt bother us. Just lasts a little while.

The only reason we would consider doing this is if it was of any benefit to us ie we wouldn't smell our cooking when we open the back door or are sitting on our decking. But as Wia mentioned and crucially is that yes it would help alot but when it's gusty or windy the smell would still be smelt by him and us and would still blow into his windows. Which leads me to think we also have a pipe coming out for the gas boiler and when the gas boiler gives off a little gas smell at times when first turning on and our window is open we always smell it so that means even with a pipe vent wind will still blow it in.

Isnt it the case that if we added the external pipe it is still going to be blowing and coming out? How will it stop the smells blowong back into the windows or our back door when open? Is it because it will be directed higher up? And will help reduce the smells? As it will be blowing a bit of a different direction? 

I did ask the conpany who did all this work and they didn't recomend doing this. They said the wind would still blow the smells around and if anything would be smelt by him more as would be higher up closer to his bedroom window. They also said rain and dirt would get into it but don't see how as it wouod have the exact same flat cover on it. They also said the air pressure wouldn't work as well as it would have to travel futher and therefore not be quite as effective? Is this true? 

They said if we did wish to do it then these are the parts needed below.

Thanks WIA for the very helpful links which obviously show basically the same as below but in a mainly square type shape which would look nicer than the ones below. But would they be suitable for a 150mm pipe that I have? And are those square pipes have the same overall width as 150mm so not condensing the airflow?

https://www.ducting-express.co.uk/product/ducting-fittings/plastic-ducting/round-plastic-ducting/round-plastic-ducting-150mm-diameter/150mm-rigid-plastic-duct-2000mm-long

https://www.ducting-express.co.uk/product/150mm-rigid-plastic-pipe-connector

https://www.ducting-express.co.uk/product/150mm-rigid-plastic-90-bend

https://www.ducting-express.co.uk/product/ventilation-grille-with-mesh-150-diameter-white

WIAWSNB

blackstar said:

Yes thank you both for your help. It cost us £2k to get the kitchen ceiling plastered and the cooker hood externally vented. As well as 3 full days if disruption.

Yes it is a 150m pipe. Half goes under ceiling and the other half that goes out wall is boxed in and plastered over. I'm struggling to understand this. How does the pipe get to the boxed-in part?

So was very dissapointed when he said the wind blows the smell into his bedroom as the wind always blows for some reason from our house to his. He has his bedroom windows open but the vent is just above our downstairs kitchen window. He said it blows into all his windows, upstairs and down stairs. 

No he wasn't grateful for what we have done si far. He did say though that now the smell doesn't stay in his bedroom 24 hours a day it only smells when we cook and then goes away. He keeps all his windows open 247. Your new outside photo helps to explain what's going on. I have to say, I think you have done more than is reasonable and can be expected, and I doubt very much whether he'd have a legitimate claim against you for a cooking smell nuisance - I suspect nigh on impossible. Having said that, if you do specialise in particularly 'smelly' foods, then it obviously will be an annoyance, so I'm pleased that the steps you are taking should benefit you too. But you could - if you wanted to - challenge his lack of gratitude and appreciation, informing him you have gone beyond the call, and you can now stop if he doesn't show more respect. He always has the option of moving to a detached property if he's that fussy...

We do smell neighbours cooking coming into our windows from the house to the other side. Doesnt bother us. Just lasts a little while. That is quite normal. I presume what this guy is complaining about is significantly stronger? If not, tell him where to go.

The only reason we would consider doing this is if it was of any benefit to us ie we wouldn't smell our cooking when we open the back door or are sitting on our decking. But as Wia mentioned and crucially is that yes it would help alot but when it's gusty or windy the smell would still be smelt by him and us and would still blow into his windows. Which leads me to think we also have a pipe coming out for the gas boiler and when the gas boiler gives off a little gas smell at times when first turning on and our window is open we always smell it so that means even with a pipe vent wind will still blow it in.

Isnt it the case that if we added the external pipe it is still going to be blowing and coming out? How will it stop the smells blowong back into the windows or our back door when open? Is it because it will be directed higher up? And will help reduce the smells? As it will be blowing a bit of a different direction? Your exterior photo has helped a lot, and I have to say I originally assumed that a short length of vertical ducting would get the exhaust out near your eaves - that's clearly not the case any more! Is that a very wide upstairs window we can see at the top of the pic? If so, then - yes - my idea would only divert the smell up to that window.

I did ask the conpany who did all this work and they didn't recomend doing this. They said the wind would still blow the smells around and if anything would be smelt by him more as would be higher up closer to his bedroom window. They also said rain and dirt would get into it but don't see how as it wouod have the exact same flat cover on it. They also said the air pressure wouldn't work as well as it would have to travel futher and therefore not be quite as effective? Is this true? Yes, any additional ducting will restrict the flow to some extent. However, your extractor should be able to cope - if necessary, it just needs to be on a higher speed. Yes, unless the new outlet clears the windows above, then these windows will become the new victims. So, I wouldn't bother unless you can get past these upstairs windows.

They said if we did wish to do it then these are the parts needed below. Yes - similar idea, but they seem to have in mind something like a soil vent pipe.

Thanks WIA for the very helpful links which obviously show basically the same as below but in a mainly square type shape which would look nicer than the ones below. But would they be suitable for a 150mm pipe that I have? And are those square pipes have the same overall width as 150mm so not condensing the airflow?

https://www.ducting-express.co.uk/product/ducting-fittings/plastic-ducting/round-plastic-ducting/round-plastic-ducting-150mm-diameter/150mm-rigid-plastic-duct-2000mm-long

https://www.ducting-express.co.uk/product/150mm-rigid-plastic-pipe-connector

https://www.ducting-express.co.uk/product/150mm-rigid-plastic-90-bend

https://www.ducting-express.co.uk/product/ventilation-grille-with-mesh-150-diameter-white

Bits in bold above.

Could you explain why you took the exhaust out in the middle of your room, and not in the corner near the boiler flue?

If you want a full 'cure', then I fear you will need to bring the vent outlet up to near, or even beyond, the eaves. This is what a soil vent pipe does, and it obviously works as you don't get sewer smells. But, it's a significant addition to what you currently have, and you'd really need to have it running in a straight line vertically upwards, so it would need to avoid that window.

Any chance of an even wider pic, showing the whole house wall and part of the roof?

Section62

WIAWSNB said:

This is what a soil vent pipe does, and it obviously works as you don't get sewer smells.

You don't usually get sewer smells from a soil vent pipe because the vent is there to allow air into the system rather than let it out (hence an air admittance valve being an alternative solution for internal stacks) and because unless there is a blockage the signature smell is more likely to be 'spring meadow' or 'lemon fresh', rather than a more unpleasant smell most people would associate with a sewer. A nasty smell is a good indicator that there's a blockage or some other problem.

OP, it isn't a good idea to have an extractor vent close to a security light.  So unless you get the light moved as well, you need a solution which directs the air well away from the light - i.e. don't fit a cowl which directs the flow downwards, as you'll just be directing warm humid air straight onto your light.

WIAWSNB

Section62 said:

WIAWSNB said:

This is what a soil vent pipe does, and it obviously works as you don't get sewer smells.

You don't usually get sewer smells from a soil vent pipe because the vent is there to allow air into the system rather than let it out (hence an air admittance valve being an alternative solution for internal stacks) and because unless there is a blockage the signature smell is more likely to be 'spring meadow' or 'lemon fresh', rather than a more unpleasant smell most people would associate with a sewer. A nasty smell is a good indicator that there's a blockage or some other problem.

So why are they so tall? :-)
Lemon fresh ma botty.

Section62

WIAWSNB said:

Section62 said:

WIAWSNB said:

This is what a soil vent pipe does, and it obviously works as you don't get sewer smells.

You don't usually get sewer smells from a soil vent pipe because the vent is there to allow air into the system rather than let it out (hence an air admittance valve being an alternative solution for internal stacks) and because unless there is a blockage the signature smell is more likely to be 'spring meadow' or 'lemon fresh', rather than a more unpleasant smell most people would associate with a sewer. A nasty smell is a good indicator that there's a blockage or some other problem.

So why are they so tall? :-)
Lemon fresh ma botty.

Largely because the Victorians believed in miasma theory.

blackstar

WIAWSNB said:

blackstar said:

Yes thank you both for your help. It cost us £2k to get the kitchen ceiling plastered and the cooker hood externally vented. As well as 3 full days if disruption.

Yes it is a 150m pipe. Half goes under ceiling and the other half that goes out wall is boxed in and plastered over. I'm struggling to understand this. How does the pipe get to the boxed-in part?

So was very dissapointed when he said the wind blows the smell into his bedroom as the wind always blows for some reason from our house to his. He has his bedroom windows open but the vent is just above our downstairs kitchen window. He said it blows into all his windows, upstairs and down stairs. 

No he wasn't grateful for what we have done si far. He did say though that now the smell doesn't stay in his bedroom 24 hours a day it only smells when we cook and then goes away. He keeps all his windows open 247. Your new outside photo helps to explain what's going on. I have to say, I think you have done more than is reasonable and can be expected, and I doubt very much whether he'd have a legitimate claim against you for a cooking smell nuisance - I suspect nigh on impossible. Having said that, if you do specialise in particularly 'smelly' foods, then it obviously will be an annoyance, so I'm pleased that the steps you are taking should benefit you too. But you could - if you wanted to - challenge his lack of gratitude and appreciation, informing him you have gone beyond the call, and you can now stop if he doesn't show more respect. He always has the option of moving to a detached property if he's that fussy...

We do smell neighbours cooking coming into our windows from the house to the other side. Doesnt bother us. Just lasts a little while. That is quite normal. I presume what this guy is complaining about is significantly stronger? If not, tell him where to go.

The only reason we would consider doing this is if it was of any benefit to us ie we wouldn't smell our cooking when we open the back door or are sitting on our decking. But as Wia mentioned and crucially is that yes it would help alot but when it's gusty or windy the smell would still be smelt by him and us and would still blow into his windows. Which leads me to think we also have a pipe coming out for the gas boiler and when the gas boiler gives off a little gas smell at times when first turning on and our window is open we always smell it so that means even with a pipe vent wind will still blow it in.

Isnt it the case that if we added the external pipe it is still going to be blowing and coming out? How will it stop the smells blowong back into the windows or our back door when open? Is it because it will be directed higher up? And will help reduce the smells? As it will be blowing a bit of a different direction? Your exterior photo has helped a lot, and I have to say I originally assumed that a short length of vertical ducting would get the exhaust out near your eaves - that's clearly not the case any more! Is that a very wide upstairs window we can see at the top of the pic? If so, then - yes - my idea would only divert the smell up to that window.

I did ask the conpany who did all this work and they didn't recomend doing this. They said the wind would still blow the smells around and if anything would be smelt by him more as would be higher up closer to his bedroom window. They also said rain and dirt would get into it but don't see how as it wouod have the exact same flat cover on it. They also said the air pressure wouldn't work as well as it would have to travel futher and therefore not be quite as effective? Is this true? Yes, any additional ducting will restrict the flow to some extent. However, your extractor should be able to cope - if necessary, it just needs to be on a higher speed. Yes, unless the new outlet clears the windows above, then these windows will become the new victims. So, I wouldn't bother unless you can get past these upstairs windows.

They said if we did wish to do it then these are the parts needed below. Yes - similar idea, but they seem to have in mind something like a soil vent pipe.

Thanks WIA for the very helpful links which obviously show basically the same as below but in a mainly square type shape which would look nicer than the ones below. But would they be suitable for a 150mm pipe that I have? And are those square pipes have the same overall width as 150mm so not condensing the airflow?

https://www.ducting-express.co.uk/product/ducting-fittings/plastic-ducting/round-plastic-ducting/round-plastic-ducting-150mm-diameter/150mm-rigid-plastic-duct-2000mm-long

https://www.ducting-express.co.uk/product/150mm-rigid-plastic-pipe-connector

https://www.ducting-express.co.uk/product/150mm-rigid-plastic-90-bend

https://www.ducting-express.co.uk/product/ventilation-grille-with-mesh-150-diameter-white

Bits in bold above.

Could you explain why you took the exhaust out in the middle of your room, and not in the corner near the boiler flue?

If you want a full 'cure', then I fear you will need to bring the vent outlet up to near, or even beyond, the eaves. This is what a soil vent pipe does, and it obviously works as you don't get sewer smells. But, it's a significant addition to what you currently have, and you'd really need to have it running in a straight line vertically upwards, so it would need to avoid that window.

Any chance of an even wider pic, showing the whole house wall and part of the roof?

Thank you very much for the reply. 

So in answer to your helpful questions.

1) Foods - just regular foods. The main issue has been my full Scottish breakfast I like to make alot of mornings  I am guessing it's the bacon that he takes issue with. 

2) So the ducking departs from the top of the vent above the plastered ceiling. It then drops below the ceiling where you see it boxed in. It had to go underneath the ceiling as there were joists in the way as the joists ran parallel which is why it could go under the ceiling in a parallel fashion but not the other direction.

3) yes it is a very wide upstairs window so all it wouod mean is the smells would be diverted thar direction ie closer to the upstairs window. 
Only other options would be a very long ducking all the way up to the eves. Past the gutters. But that is an extreme measure and may compromise the air pressure as it would have such a long way to travel.? Do you think? Would the air pressure be strong enough to go all that distance? Guess would have to turn it on when its being installed and someone up on a ladder to see if the air pressure is still blowing out strongly? And if not then have to dismantle it all and probably loose our money on all the parts?

If we did do this would those parts I linked to that the company gave us be sufficient? If we were to vent past the guttering then wouldn't we need to measure the height of from the current outside vent all the way up to the guttering and make sure the ducting was long enough? Not sure how long the ducting is that they sent me the link for?


4) yes I shall get a wider photo. 

5) there wasn't the space to vent next to the boiler unfortunately.

6) do I really have to either move the security lughts or to get ducting  away from the security lights? Wonder why  the conpany didnt mention this? Whats the consequences of leaving it next to the security lights? 


7) theothet issue is the ducting wouod have to go past the upper bedroom window which would restrict our view. How couod we get arouhd that ?  Could we ask them to put the ducting at an angle slightly so it passes the window?

8l) looks like the ducting thr company gave us was only about 6 feet long. Wouod need to be much longer than this to go past the gutering. Also not sure if this company do longer ducting  or if two can be combined. 

9) How can we avoid dirt and rain and also prevent vermin getting into the duxting if we put it above the guttering?

WIAWSNB

blackstar said:

Thank you very much for the reply. 

So in answer to your helpful questions.

1) Foods - just regular foods. The main issue has been my full Scottish breakfast I like to make alot of mornings  I am guessing it's the bacon that he takes issue with. Tsk tsk. Yummy smell - but i can well imagine it's annoying if you aren't participating...

2) So the ducking departs from the top of the vent above the plastered ceiling. It then drops below the ceiling where you see it boxed in. It had to go underneath the ceiling as there were joists in the way as the joists ran parallel which is why it could go under the ceiling in a parallel fashion but not the other direction.
Wow - tortuous route.
3) yes it is a very wide upstairs window so all it wouod mean is the smells would be diverted thar direction ie closer to the upstairs window. 
Only other options would be a very long ducking all the way up to the eves. Past the gutters. But that is an extreme measure and may compromise the air pressure as it would have such a long way to travel.? Do you think? Would the air pressure be strong enough to go all that distance? Guess would have to turn it on when its being installed and someone up on a ladder to see if the air pressure is still blowing out strongly? And if not then have to dismantle it all and probably loose our money on all the parts? Yes, it's a longer route, compounded by the unfortunate layout already inside the house. Yes, it's bound to have an addidional effect, but there are many houses with equally long ducting routes inside their lofts, heading to the walls. So, yes, it ain't ideal, but it should still extract. Likely you'll need to run your extractor on higher than usual settings.

If we did do this would those parts I linked to that the company gave us be sufficient? If we were to vent past the guttering then wouldn't we need to measure the height of from the current outside vent all the way up to the guttering and make sure the ducting was long enough? Not sure how long the ducting is that they sent me the link for? That's the issue - how to run the ducting neatly. If you go for this, I'd be tempted to either use a conventional 4" soil vent pipe (you'll likely have one elsewhere on your house?), or the flat ducting I linked to.


4) yes I shall get a wider photo. Ta.

5) there wasn't the space to vent next to the boiler unfortunately. That's a shame. I'd have much rather a rectangular ducting heading there, and out the wall above or to the side of the boiler flue. Ducting could then be taken pretty much straight up that wall. Easy to say!

6) do I really have to either move the security lughts or to get ducting  away from the security lights? Wonder why  the conpany didnt mention this? Whats the consequences of leaving it next to the security lights? I wouldn't worry too much. The lights are designed for outdoor conditions, so I can't see a bit of steam affecting them. It might cause the odd false triggering in cold weather, but again hardly a big issue.


7) the othet issue is the ducting wouod have to go past the upper bedroom window which would restrict our view. How couod we get arouhd that ?  Could we ask them to put the ducting at an angle slightly so it passes the window? Not at a slopy (or sloppy...) angle, as that would look hellish. But the use of 45o elbows would get past the window.

8l) looks like the ducting the company gave us was only about 6 feet long. Wouod need to be much longer than this to go past the gutering. Also not sure if this company do longer ducting  or if two can be combined. If you are going to do this, I'd get it just up past the guttering. Again, I'd be tempted to use normal vent pipe.

9) How can we avoid dirt and rain and also prevent vermin getting into the duxting if we put it above the guttering? With a grille as before. And a drain hole or collecting point at the bottom. 

Bits in bold ^

What a 'mare. Really your call. I think your neighbour would be stuffed if you just said, "I've done more than could be asked, and at huge cost to me. There is nothing unusual about what you are now still smelling." I cannot see any possible way he could force you to do more.

The only easy improvements I can see are to duct the outlet upwards, above the gutter. Yes, even then there will be the odd strange wind that'll blow the smell downwards on occasion, but it should make a significant overall difference, imo. The Q is - how to best run the ducting? And, which ducting to use.

I personally wouldn't go 6" round, unless you are prepared to accept how awkward it will likely look. Having said that, I guess it's possible to run a climbing plant up it?!

Failing that, it's either 4" 'soil vent' pipe, or 8x2 rect ducting. Best route? No idea.

blackstar

Thank you very much WIA as this is incredibly helpful. I have taken notes from your 1st class advice. So if we do decide to go ahead with it then we have excellent information to ensure its done correctly.

Not really keen on getting it done to be honest. Although part of me thinks it will be nice to get cooking smells far and away. So think I might go ahead with it but I just need to ensure I order the exact and correct parts and then get in touch with a tradesman and say "here's all you need, please install this as per your excellent photo where there's an elbow". 

This is the hardest part for me, to order all the correct parts being someone who has zero diy experience. So I would be most grateful if you are able to post links to all the parts I need so I can order them and then give to a tradesman. 

I also emailed a company who do ducking and ask for help with what parts I would specifically need.
This was their response.

Please see below answers to your questions.

1) how I can avoid rain, dirt and vermin entering into the ventilation grille?

People tend to use https://www.ducting-express.co.uk/product/ducting-fittings/grilles-louvres/gravity-shutters/gravity-shutter-150-diameter-white for the exit, this will prevent any water entering back through the grille, but please be aware that there isn’t an insect mesh on the spigot, you can get this for quite cheap and install it onto the shutter yourself. Unfortunately, if vermin want to enter, they will. There is nothing stopping them, and we do not supply anything that could prevent this happening.

2) Will the ventilation grille be facing the sky (vertically) or facing the garden as it is now (horizontal)?

If you get the one linked above, this will face the ground, and as airflow passes through, the shutter will open and when the hood isn’t in use it’ll stay closed. If you wanted to stay with a ventilation grille with mesh, this’d be facing the ground.

3) Will I need to measure the length of ducting I need to get from the current position to the position I wish ie past the guttering and if so do you have ducting long enough or if not can some ducting be added to other ducting? And if so please can you give me the parts needed for this? It's a 150mm pipe I have from the cooker hood. 

I can see you linked plastic pipe, and the longest length we do is 2 meters. If you needed to extend this, you would use - https://www.ducting-express.co.uk/product/ducting-fittings/plastic-ducting/round-plastic-ducting/round-plastic-ducting-150mm-diameter/150mm-rigid-plastic-pipe-connector

4).please send me links to another parts I need other than the ones listed below.

Unfortunately, I cannot tell you exactly what you need, we can only advise as we do not design kitchen extraction systems.

WIAWSNB

Which of the two routes are you thinking of?