Hi

After much conflicting advice from a number of people I thought I'd go
after some more from you all

I need to install a cooker hood. The purpose of this is to:

1) Remove smoke/steam etc from the kitchen
2) Ventilate the kitchen: kitchen/diner gets too hot when/after cooking.

The hood will sit a fair distance (about 3m vert+horiz) from the outside
wall, but directly on the (as yet unchecked) wall in front of the
chimney flue.

The comments I have had are

1) There is no point in having 3m venting as it just doesn't work and is
ugly. Should just do recirculating with carbon filter.
2) Recirculating no good at reducing heat. Should either vent or
recirculate plus add a separate fan in the kitchen.
3) Separate fan doesn't work well as it doesn't extract from where the
heat/smoke is produced. Should vent. Consider adding additional fan in
vent to increase power.
4) Adding additional fan problematic as cannot control from hood.
5) Throughput with recirculation less than with venting due to filter
obstruction.

In addition I was wondering if there is any point in venting to the
chimney flue. Possible plus is the there may be a little draw from the
chimney (even without a fire), and it would be a lot more attractive.
Possible -ve is that smoke would just fall back down the chimney or vent
would not cope, so it would be pointless.

I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Thanks in advance.

Amos

Amos wrote:

I need to install a cooker hood. The purpose of this is to:

1) Remove smoke/steam etc from the kitchen
2) Ventilate the kitchen: kitchen/diner gets too hot when/after cooking.

Recirculating will achieve neither. It will reduce smells to some
degree, but that's all. All the heat, and more importantly the water
vapour, stay in the kitchen.


The hood will sit a fair distance (about 3m vert+horiz) from the outside
wall

This is not very far. Our vent has a total run of 2.5m and works great.



1) There is no point in having 3m venting as it just doesn't work and is
ugly. Should just do recirculating with carbon filter.
2) Recirculating no good at reducing heat. Should either vent or
recirculate plus add a separate fan in the kitchen.
3) Separate fan doesn't work well as it doesn't extract from where the
heat/smoke is produced. Should vent. Consider adding additional fan in
vent to increase power.
4) Adding additional fan problematic as cannot control from hood.
5) Throughput with recirculation less than with venting due to filter
obstruction.

IMO recirculating hoods are only just very slightly better than nothing.
Venting is far, far better.

The quality of the hood makes a huge difference to how well it extracts.
We bought a twin fan hood from Elica, which works much, much better than
our old Baumatic hood used to.

I'd recommend using a venting hood, and installing the biggest diameter
duct you can. 5" is much better than 4".


In addition I was wondering if there is any point in venting to the
chimney flue. Possible plus is the there may be a little draw from the
chimney (even without a fire), and it would be a lot more attractive.
Possible -ve is that smoke would just fall back down the chimney or vent
would not cope, so it would be pointless.

I wouldn't consider that as an option - too many variables, and unlikely
to work.


--
Grunff

On Sun, 19 Jun 2005 17:14:33 +0100,it is alleged that Grunff
spake thusly in uk.d-i-y:


In addition I was wondering if there is any point in venting to the
chimney flue. Possible plus is the there may be a little draw from the
chimney (even without a fire), and it would be a lot more attractive.
Possible -ve is that smoke would just fall back down the chimney or vent
would not cope, so it would be pointless.

I wouldn't consider that as an option - too many variables, and unlikely
to work.

Just to add to that, there is the fact that all hoods, even filtered
ones will expel some grease and lots of moisture in the exhaust.
Having that building up in a chimney over time is likely to be very
bad odour wise and health wise, and may even cause condensation
problems, so that's a definite no.

I would definitely go with vented. MUCH better than a recirc.:-)


--
"Anyone who is capable of getting themselves made President should on
*no* account be allowed to do the job."
- The Hitchhiker's Guide to the Galaxy

On Sun, 19 Jun 2005 15:46:45 GMT, Amos
wrote:

Hi

After much conflicting advice from a number of people I thought I'd go
after some more from you all

I need to install a cooker hood. The purpose of this is to:

1) Remove smoke/steam etc from the kitchen
2) Ventilate the kitchen: kitchen/diner gets too hot when/after cooking.

The hood will sit a fair distance (about 3m vert+horiz) from the outside
wall, but directly on the (as yet unchecked) wall in front of the
chimney flue.

The comments I have had are

1) There is no point in having 3m venting as it just doesn't work and is
ugly. Should just do recirculating with carbon filter.

Ugly is a matter of opinion, and how well you do the vent pipe

2) Recirculating no good at reducing heat. Should either vent or
recirculate plus add a separate fan in the kitchen.

Recirculating will make the room wharmer, as you have the heat from
the fan to add in

3) Separate fan doesn't work well as it doesn't extract from where the
heat/smoke is produced. Should vent. Consider adding additional fan in
vent to increase power.

I think these fans look really ugly

4) Adding additional fan problematic as cannot control from hood.

5) Throughput with recirculation less than with venting due to filter
obstruction.

Debatable

In addition I was wondering if there is any point in venting to the
chimney flue. Possible plus is the there may be a little draw from the
chimney (even without a fire), and it would be a lot more attractive.
Possible -ve is that smoke would just fall back down the chimney or vent
would not cope, so it would be pointless.

You could run the vent pipe right up the chinmey to the pot, but its
hard work ...


I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Thanks in advance.

Amos

On Sun, 19 Jun 2005 17:14:33 +0100, Grunff wrote:



The quality of the hood makes a huge difference to how well it extracts.
We bought a twin fan hood from Elica, which works much, much better than
our old Baumatic hood used to.

I'd recommend using a venting hood, and installing the biggest diameter
duct you can. 5" is much better than 4".


Agreed.

Take a look at a fairly powerful blower and 120mm or 150mm duct for
this kind of length. Try to avoid sharp corners in the ducting by
using the flexible type if possible.

Take a look at Elica, an Italian manufacturer. Elica make their own
branded products plus virtually all for other vendors in Europe on a
private label basis.

Their UK distributor is DR Cooker Hoods

http://www.elica.co.uk/

This site is useful for the catalogue.

DR don't supply directly but through resellers such as TLC Electrical
and others. It's worth shopping around for best price.

I fitted one of their Built-in 80 Ultra models a couple of years ago
and it's excellent.

It's well worth getting the kind with metal mesh grease filters
because these can simply be taken out and washed.




--

..andy

To email, substitute .nospam with .gl

The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

In article , Rick
writes
On Sun, 19 Jun 2005 15:46:45 GMT, Amos
wrote:

In addition I was wondering if there is any point in venting to the
chimney flue. Possible plus is the there may be a little draw from the
chimney (even without a fire), and it would be a lot more attractive.
Possible -ve is that smoke would just fall back down the chimney or vent
would not cope, so it would be pointless.

You could run the vent pipe right up the chinmey to the pot, but its
hard work ...

That would be my choice, using a flexible stainless steel flue liner and a
vent cap on top. 5" for a 2 storey or 6" for a town house, expect to pay
8-10quid a metre but worth it I think.
--
fred

"Amos" wrote in message
k...
Hi

After much conflicting advice from a number of people I thought I'd go
after some more from you all

I need to install a cooker hood. The purpose of this is to:

1) Remove smoke/steam etc from the kitchen
2) Ventilate the kitchen: kitchen/diner gets too hot when/after cooking.

The hood will sit a fair distance (about 3m vert+horiz) from the outside
wall, but directly on the (as yet unchecked) wall in front of the chimney
flue.

The comments I have had are

1) There is no point in having 3m venting as it just doesn't work

How do you know it doesn't work?

Mary

On Sun, 19 Jun 2005 20:02:01 +0100,it is alleged that "Mary Fisher"
spake thusly in uk.d-i-y:

The comments I have had are

1) There is no point in having 3m venting as it just doesn't work

How do you know it doesn't work?


I read this as meaning this is an opinion from someone else, and we're
being asked our opinion on this opinion :-)

Mary



--
There are three things which I consider excellent advice. First, don't
smoke to excess. Second, don't drink to excess.
Third, don't marry to excess.
- Mark Twain

"Chip" wrote in message
n.net...
On Sun, 19 Jun 2005 20:02:01 +0100,it is alleged that "Mary Fisher"
spake thusly in uk.d-i-y:

The comments I have had are

1) There is no point in having 3m venting as it just doesn't work

How do you know it doesn't work?


I read this as meaning this is an opinion from someone else, and we're
being asked our opinion on this opinion :-)

Oh ... I THINK I know what you mean :-)

Mary

Mary



--
There are three things which I consider excellent advice. First, don't
smoke to excess. Second, don't drink to excess.
Third, don't marry to excess.
- Mark Twain

Chip wrote:

On Sun, 19 Jun 2005 17:14:33 +0100,it is alleged that Grunff
spake thusly in uk.d-i-y:



In addition I was wondering if there is any point in venting to the
chimney flue. Possible plus is the there may be a little draw from the
chimney (even without a fire), and it would be a lot more attractive.
Possible -ve is that smoke would just fall back down the chimney or vent
would not cope, so it would be pointless.

I wouldn't consider that as an option - too many variables, and unlikely
to work.


Just to add to that, there is the fact that all hoods, even filtered
ones will expel some grease and lots of moisture in the exhaust.
Having that building up in a chimney over time is likely to be very
bad odour wise and health wise, and may even cause condensation
problems, so that's a definite no.

Good point. Mice are enough of a problem in Edinburgh flats already?

I would definitely go with vented. MUCH better than a recirc.:-)

That was my feeling, so I was a little put out when I was told it
wouldn't be effective. However I am glad to hear that everyone is pretty
much consistent on this

Thanks

Amos

Grunff wrote:
snip
The quality of the hood makes a huge difference to how well it extracts.
We bought a twin fan hood from Elica, which works much, much better than
our old Baumatic hood used to.

Thanks for all your comments. The twin fan hood - do you mean one with
an additional external motor.

I'd recommend using a venting hood, and installing the biggest diameter
duct you can. 5" is much better than 4".

Elica seem to have quite a few 6" hoods. I'll probably go for that. It
is a kitchen diner, so it really needs to be kept clear.

Thanks

Amos

Amos wrote:

Thanks for all your comments. The twin fan hood - do you mean one with
an additional external motor.

You're welcome. By twin fan, I mean one with two motors/fans within the
housing, like the Concorde Twin
http://www.elica.co.uk/master.asp?http://www.elica.co.uk/view_products_parent.asp?Freestanding%20Hoods


Elica seem to have quite a few 6" hoods. I'll probably go for that. It
is a kitchen diner, so it really needs to be kept clear.

I'd be surprised if you don't get a good result with a decent hood.


--
Grunff

I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Recirculating doesn't work. At all.

You can vent 3m no problem. However, you MUST use a centrifugal fan. An
axial fan is not capable of doing it, as single stage axial fans can't
produce sufficient compression. Use the largest ducting you can
aesthetically fit.

Christian.

Amos wrote:
Hi

After much conflicting advice from a number of people I thought I'd go
after some more from you all

I need to install a cooker hood. The purpose of this is to:

1) Remove smoke/steam etc from the kitchen
2) Ventilate the kitchen: kitchen/diner gets too hot when/after cooking.

The hood will sit a fair distance (about 3m vert+horiz) from the outside
wall, but directly on the (as yet unchecked) wall in front of the
chimney flue.

The comments I have had are

1) There is no point in having 3m venting as it just doesn't work and is
ugly. Should just do recirculating with carbon filter.

I recently fitted a Baumatic built-in extractor
(http://www.tlc-direct.co.uk/Products/BMCAN54SS.html) which works
*extremely* well with a 4m ducting run (with a right-angle bend after
the first metre) using 6" rigid ducting hidden in the ceiling void.

This particular extractor has a free-flow flowrate of 500m3/hr and,
having gone through the back pressure figures and fan curves I
calculate it now runs at ~400m3/hr.

Condensation in the kitchen and cooking smells in the rest of house are
now a thing of the past, and for =A3150 (fan+ducting) all-in I couldn't
believe the bang-for-buck ratio - and it looks superb to boot.

It works so well that after installating it I went through half a box
of smoke matches due to sheer admiration of its effectiveness... but
then I'm sad like that.

Mathew

On Mon, 20 Jun 2005 10:24:59 +0100, "Christian McArdle"
wrote:

I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Recirculating doesn't work. At all.

You can vent 3m no problem. However, you MUST use a centrifugal fan. An
axial fan is not capable of doing it, as single stage axial fans can't
produce sufficient compression. Use the largest ducting you can
aesthetically fit.

Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.

Mark

Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.

And specifically avoid ribbed flexible ducting.

Christian.

Mark wrote:
"Christian McArdle" wrote:
You can vent 3m no problem. However, you MUST use a centrifugal fan. An
axial fan is not capable of doing it, as single stage axial fans can't
produce sufficient compression. Use the largest ducting you can
aesthetically fit.

Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.

You can also use grey soil pipe and fittings, which are cheaper.

Thanks. Actually, my mistake - it is actually 3m horiz + right angle +
another metre and a half, so it is rather long.

Even so, in light of comments here, I will vent. thanks

Amos


Grunff wrote:
Amos wrote:

Thanks for all your comments. The twin fan hood - do you mean one with
an additional external motor.


You're welcome. By twin fan, I mean one with two motors/fans within the
housing, like the Concorde Twin
http://www.elica.co.uk/master.asp?http://www.elica.co.uk/view_products_parent.asp?Freestanding%20Hoods



Elica seem to have quite a few 6" hoods. I'll probably go for that. It
is a kitchen diner, so it really needs to be kept clear.


I'd be surprised if you don't get a good result with a decent hood.

Mark wrote:

On Mon, 20 Jun 2005 10:24:59 +0100, "Christian McArdle"
wrote:


I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Recirculating doesn't work. At all.

You can vent 3m no problem. However, you MUST use a centrifugal fan. An
axial fan is not capable of doing it, as single stage axial fans can't
produce sufficient compression. Use the largest ducting you can
aesthetically fit.


Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.

Call me stupid I could not find any at BES. I plan to use solid duct
pipes rather than flexible. Although square makes a bit of a difference,
given I cannot go invisible on that one, I might compomise for square.

Amos

Mark wrote:

On Mon, 20 Jun 2005 10:24:59 +0100, "Christian McArdle"
wrote:


I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Recirculating doesn't work. At all.

You can vent 3m no problem. However, you MUST use a centrifugal fan. An
axial fan is not capable of doing it, as single stage axial fans can't
produce sufficient compression. Use the largest ducting you can
aesthetically fit.


Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.


Turns out Elica want to charge me 200 quid for the ducting. Ha ha.

However I don't really know what I should be paying. Any ideas for 1.5m
+ 90 degrees + 3m + wall plate of 150mm diameter. I've got it down to
110, but that still seems stupidly high. What should I really be looking
for and where. I am clearly missing something.

Thanks for any help.

Amos

On Tue, 21 Jun 2005 13:32:21 +0100, "Christian McArdle"
wrote:

Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.

And specifically avoid ribbed flexible ducting.

Christian.

.... but smooth interior is a good choice because you can create much
slower bends than are typical for solid ducts.



--

..andy

To email, substitute .nospam with .gl

The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

Amos wrote:

However I don't really know what I should be paying. Any ideas for 1.5m
+ 90 degrees + 3m + wall plate of 150mm diameter. I've got it down to
110, but that still seems stupidly high. What should I really be looking
for and where. I am clearly missing something.

I used aluminium duct from BES (125mm). They also do a 150mm.
http://www.bes.ltd.uk/products/181.asp


--
Grunff

On Tue, 21 Jun 2005 20:40:58 GMT, Amos
wrote:



Mark wrote:

On Mon, 20 Jun 2005 10:24:59 +0100, "Christian McArdle"
wrote:


I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Recirculating doesn't work. At all.

You can vent 3m no problem. However, you MUST use a centrifugal fan. An
axial fan is not capable of doing it, as single stage axial fans can't
produce sufficient compression. Use the largest ducting you can
aesthetically fit.


Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.

Call me stupid I could not find any at BES. I plan to use solid duct
pipes rather than flexible. Although square makes a bit of a difference,
given I cannot go invisible on that one, I might compomise for square.

If you select "Installation" on the left hand (index) then
"Ventilation" on the pop-up menu and finally "Ventilation, Ducting and
Accessories". Skip all the rectangular stuff at the top and the
circular ducting starts near the bottom of the page.

Hope this helps.

Mark.

On Tue, 21 Jun 2005 13:32:21 +0100, "Christian McArdle"
wrote:

Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.

And specifically avoid ribbed flexible ducting.

You mean the stuff with a spiral wound wire?

I use this and it seems OK (it's well stretched out
though).

Mark.

I use this and it seems OK (it's well stretched out
though).

It absolutely trashes the airflow, though.

Christian.

Amos wrote:

Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.


Turns out Elica want to charge me 200 quid for the ducting. Ha ha.

However I don't really know what I should be paying. Any ideas for 1.5m
+ 90 degrees + 3m + wall plate of 150mm diameter. I've got it down to
110, but that still seems stupidly high. What should I really be looking
for and where. I am clearly missing something.

Thanks for any help.

Amos

I got all mine from http://www.fansdirect.co.uk/ Their catalogue
doesn't cover their entire stock so here're the part numbers and prices
(exc. VAT) for my stuff:

PVC693WH Connector for 150mm=D8(ID) pipe =A33.40
PVC696WH Pipe Fastener to suit 150mm=D8 pipe =A32.20
PVC690WH 90=B0 bend (PVC) to suit 150mm=D8(ID) pipe =A312.00
PVC1200-6WH 150mm=D8 rigid PVC pipe, 2m length =A310.50

Free delivery for orders =A310.

(Note: 90=B0 bend looks quite pricey so I may have bought that
elsewhere.. BES?)

I bought the outlet plate (gravity flaps) from Screwfix
(http://www.screwfix.com/app/sfd/cat/...523&ts=3D43615) - at
the time of purchase it didn't feature in the paper catalogues.. this
may have changed now.

I did quite a bit of searching round to get the best prices -
admittedly this search was limited to the Internet (me being a lazy
arse and all) and the local sheds. You might be able to pick up
something cheaper from the 'specialists'.

Mathew

P=2ES. Incidentaly, looking at both the BES and FansDirect product codes
it would appear that it's pretty much all manufactured by Domus
(http://www.domusventilation.com/index2.htm) whose catalogue is well
worth downloaded for the item lists/descriptions and back pressure
figures.

Thank you very much.

Amos

Mark wrote:

On Tue, 21 Jun 2005 20:40:58 GMT, Amos
wrote:



Mark wrote:


On Mon, 20 Jun 2005 10:24:59 +0100, "Christian McArdle"
wrote:



I would really appreciate any helpful comments anyone has on these
options, especially if any of the arguments are fallacious.

Recirculating doesn't work. At all.

You can vent 3m no problem. However, you MUST use a centrifugal fan. An
axial fan is not capable of doing it, as single stage axial fans can't
produce sufficient compression. Use the largest ducting you can
aesthetically fit.


Also use circular section ducting rather than "space-saving"
rectangular section. BES stock a good selection.


Call me stupid I could not find any at BES. I plan to use solid duct
pipes rather than flexible. Although square makes a bit of a difference,
given I cannot go invisible on that one, I might compomise for square.


If you select "Installation" on the left hand (index) then
"Ventilation" on the pop-up menu and finally "Ventilation, Ducting and
Accessories". Skip all the rectangular stuff at the top and the
circular ducting starts near the bottom of the page.

Hope this helps.

Mark.

Mathew J. Newton wrote:
I got all mine from http://www.fansdirect.co.uk/ Their catalogue
doesn't cover their entire stock so here're the part numbers and prices
(exc. VAT) for my stuff:

PVC693WH Connector for 150mm=D8(ID) pipe =A33.40
PVC696WH Pipe Fastener to suit 150mm=D8 pipe =A32.20
PVC690WH 90=B0 bend (PVC) to suit 150mm=D8(ID) pipe =A312.00
PVC1200-6WH 150mm=D8 rigid PVC pipe, 2m length =A310.50

Free delivery for orders =A310.

(Note: 90=B0 bend looks quite pricey so I may have bought that
elsewhere.. BES?)

Oops - just realised I posted a load of symbols which may not come out
correctly in everyone's newsreader. Any '=3DA3' is a pound sign, thus the
2m pipe us GBP10.50 etc.

Sorry if this causes confusion...

Mathew

On Wed, 22 Jun 2005 10:57:14 +0100, "Christian McArdle"
wrote:

I use this and it seems OK (it's well stretched out
though).

It absolutely trashes the airflow, though.

Is it any worse than a 90 degree bend though? What would be a better
alternative?

Mark.

It absolutely trashes the airflow, though.

Is it any worse than a 90 degree bend though? What would be a better
alternative?

You can get types with a smooth internal bore. The cheaper ribbed types
cause turbulence in the flow, dramatically increasing resistance.

Christian.

On Thu, 23 Jun 2005 09:30:12 +0100, "Christian McArdle"
wrote:

It absolutely trashes the airflow, though.

Is it any worse than a 90 degree bend though? What would be a better
alternative?

You can get types with a smooth internal bore. The cheaper ribbed types
cause turbulence in the flow, dramatically increasing resistance.

I haven't seen any like this. Are there any national/online
suppliers?

Mark