(dug out of poor design rant thread)

On 14/04/2012 00:58, sm_jamieson wrote:
On Friday, April 13, 2012 9:04:24 PM UTC+1, Adrian C wrote:
On 13/04/2012 19:27, Tim Streater wrote:


Quite. We're currently shopping for a chimmney style cooker hood. I
found one at John Lewis and downloaded the manual primarily for
checking dimensions. However, the words "not designed for extracting
steam" have now confused the selection process.

By "chimney style" do you mean it's a faux chimney? The only type of
cooker hood that's worth a damn is one that extracts to the
*outside* of
the house.

Nope, it's a real chimney, a witches top hat above the hob. And a flat
roof overhead to vent through, so can't see how it would not extract
steam....

http://www.theappliancedepot.co.uk/j...1-s-steel-60cm

But Manual Says No...


A quick web search reveals that many extractor instructions contain
the phrase "will not extract steam". There appears to be a couple of
variants of the phrase so maybe it is copied from some kind of
regulation document.
I don't get it.
Someone suggested maybe it means most of the steam will condense in
the filters or grease trap (the wire grid).

I will have to choose an extractor hood soon also.

Can anyone explain ?

Simon.

On 14/04/12 10:26, Adrian C wrote:
(dug out of poor design rant thread)

A quick web search reveals that many extractor instructions contain
the phrase "will not extract steam". There appears to be a couple of
variants of the phrase so maybe it is copied from some kind of
regulation document.
I don't get it.
Someone suggested maybe it means most of the steam will condense in
the filters or grease trap (the wire grid).

That seems a plausible explanation. I suppose it depends how much
condensation. If enough to start dripping onto the cooking below then
unacceptable. The other consideration might be that steam condensing
within the hood might not do the fan motors any good.

--
djc

"djc" wrote in message
...
On 14/04/12 10:26, Adrian C wrote:
(dug out of poor design rant thread)

A quick web search reveals that many extractor instructions contain
the phrase "will not extract steam". There appears to be a couple of
variants of the phrase so maybe it is copied from some kind of
regulation document.
I don't get it.
Someone suggested maybe it means most of the steam will condense in
the filters or grease trap (the wire grid).

That seems a plausible explanation. I suppose it depends how much
condensation. If enough to start dripping onto the cooking below then
unacceptable. The other consideration might be that steam condensing
within the hood might not do the fan motors any good.

--
djc
There are some poncy cooker hoods just recirculate the air through a carbon
filter, ie they don't take the air.fumes outside. Maybe it's one of them?

On Saturday, April 14, 2012 5:56:13 PM UTC+1, harry wrote:
"djc" wrote in message
...
On 14/04/12 10:26, Adrian C wrote:
(dug out of poor design rant thread)

A quick web search reveals that many extractor instructions contain
the phrase "will not extract steam". There appears to be a couple of
variants of the phrase so maybe it is copied from some kind of
regulation document.
I don't get it.
Someone suggested maybe it means most of the steam will condense in
the filters or grease trap (the wire grid).

That seems a plausible explanation. I suppose it depends how much
condensation. If enough to start dripping onto the cooking below then
unacceptable. The other consideration might be that steam condensing
within the hood might not do the fan motors any good.

--
djc
There are some poncy cooker hoods just recirculate the air through a carbon
filter, ie they don't take the air.fumes outside. Maybe it's one of them?

An answer from justanswer.com

I have heard that stainless steel Cooker Hoods will not extract steam from Induction Hobs. Apparently the Induction Hob does not generate heat like a Ceramic Hob and when the hot steam hits the cold stainless steel Cooker Hood the steam condenses and water drips onto the hob.
Submitted: 1262 days and 23 hours ago.
Category: Appliance
Value: $15
Status: CLOSED
Accepted Answer
Picture
Expert: The Home Smithy replied 1262 days and 20 hours ago.

HiCustomer

That is true to a certain extent. The amount that condenses is determined by the amount of airflow that the fan draws. If sufficient the diffrence is neglegable.

If you consider that even with gas or electric power the hood is still going to take some time to warm up, you can see that this shouldnt be a big concern.

The only time I can see it being a major concern is if you are constantly boiling water.

Even then a quick wipe with a dry rag handels that.

On Saturday, April 14, 2012 5:56:13 PM UTC+1, harry wrote:
"djc" wrote in message
...
On 14/04/12 10:26, Adrian C wrote:
(dug out of poor design rant thread)

A quick web search reveals that many extractor instructions contain
the phrase "will not extract steam". There appears to be a couple of
variants of the phrase so maybe it is copied from some kind of
regulation document.
I don't get it.
Someone suggested maybe it means most of the steam will condense in
the filters or grease trap (the wire grid).

That seems a plausible explanation. I suppose it depends how much
condensation. If enough to start dripping onto the cooking below then
unacceptable. The other consideration might be that steam condensing
within the hood might not do the fan motors any good.

--
djc
There are some poncy cooker hoods just recirculate the air through a carbon
filter, ie they don't take the air.fumes outside. Maybe it's one of them?

Had a look at some manuals with this warning, they all can extract to outside.

Simon.

On 14/04/2012 17:56, harryagain wrote:
wrote in message
...
On 14/04/12 10:26, Adrian C wrote:
(dug out of poor design rant thread)

A quick web search reveals that many extractor instructions contain
the phrase "will not extract steam". There appears to be a couple of
variants of the phrase so maybe it is copied from some kind of
regulation document.
I don't get it.
Someone suggested maybe it means most of the steam will condense in
the filters or grease trap (the wire grid).

That seems a plausible explanation. I suppose it depends how much
condensation. If enough to start dripping onto the cooking below then
unacceptable. The other consideration might be that steam condensing
within the hood might not do the fan motors any good.

--
djc
There are some poncy cooker hoods just recirculate the air through a carbon
filter, ie they don't take the air.fumes outside. Maybe it's one of them?


Nope. These vent to the outside.

'Which' has recently tested some. As Quidco is paying £2 cashback per 2
month trial sign up (effectively putting me £2 in profit), I've done the
deed and downloaded their "report".

It's not a complete test. Models I'm loooking at are missing, and
comparisons and specifications I'd like to read about the products,
compared with actual physical measurements in proper units are also
sadly absent.

600mm chimney units that get 5 stars at steam performance are pretty
expensive, was thinking £300 tops - nah, £490....

--
Adrian C

It is a warranty / liability limitation.

Xpelair - your fan must be cleaned monthly by a qualified electrician.
Most are AC fans with bimetallic thermal cutout. Should the fan or
discharge vent become sufficiently blocked with dust the motor will
get hot - so hot that if insulated by dust buildup and grease deposits
the combination may ignite.

Cooker hoods - switch gear, motor, bearings, impellor are not IP-rated
or temperature-rated for continuous steam exposure. The RCD may trip
out, the motor may run its bearings, the plastic impellor or airflow
guide may melt. Grease could me migrated past the filters via steam
into the motor/impellor assembly creating a fire hazard.

Another point is steam is invisible, viciously hot close to a kettle's
outlet. The visible "steam" is lower temperature hot water vapour. I
suspect plastics used for motor housing, impellor & air ducting may
not be tolerant of continuous high temperature exposure such as when
used in recirculation mode - or even extract mode at low speeds
against a barrage of steam sources. Likewise steam jets from pressure
cookers I think can be a slightly higher temperature.

Most cooker hoods are made by Elica.
Twin motor (320m3/hr) units are good enough to get rid of heat, not
just odours & steam. Single motor (170m3/hr) are good at getting rid
of moisture, they struggle on a hot summer's day. Obviously you can
get single motor 550-800m3/hr units - but check the dB(A) figures
carefully because things can get loud, likewise check hole size.

Ebay sometimes has oddball super high flow hoods at cheap prices, you
do not have to pay the ?£3.5k? someone did per cooker hood on Grand
Designs.

On Saturday, April 14, 2012 10:29:28 PM UTC+1, js.b1 wrote:
It is a warranty / liability limitation.

Xpelair - your fan must be cleaned monthly by a qualified electrician.
Most are AC fans with bimetallic thermal cutout. Should the fan or
discharge vent become sufficiently blocked with dust the motor will
get hot - so hot that if insulated by dust buildup and grease deposits
the combination may ignite.

Cooker hoods - switch gear, motor, bearings, impellor are not IP-rated
or temperature-rated for continuous steam exposure. The RCD may trip
out, the motor may run its bearings, the plastic impellor or airflow
guide may melt. Grease could me migrated past the filters via steam
into the motor/impellor assembly creating a fire hazard.

Another point is steam is invisible, viciously hot close to a kettle's
outlet. The visible "steam" is lower temperature hot water vapour. I
suspect plastics used for motor housing, impellor & air ducting may
not be tolerant of continuous high temperature exposure such as when
used in recirculation mode - or even extract mode at low speeds
against a barrage of steam sources. Likewise steam jets from pressure
cookers I think can be a slightly higher temperature.

Most cooker hoods are made by Elica.
Twin motor (320m3/hr) units are good enough to get rid of heat, not
just odours & steam. Single motor (170m3/hr) are good at getting rid
of moisture, they struggle on a hot summer's day. Obviously you can
get single motor 550-800m3/hr units - but check the dB(A) figures
carefully because things can get loud, likewise check hole size.

Ebay sometimes has oddball super high flow hoods at cheap prices, you
do not have to pay the ?£3.5k? someone did per cooker hood on Grand
Designs.

I'm sure thats all true.
But you'd have thought they would put something in the manuals to explain whats going on, especially when most people assume a cooker hood is going to help remove "steam" (or water vapour) from their kitchen. And it will to some extent.

Anyway since I have to choose a cooker hood soon, this is a very timely discussion.

Simon.

On Apr 15, 12:02*am, sm_jamieson wrote:
But you'd have thought they would put something in
the manuals to explain whats going on

I think they should say "suitable for domestic cooking use only,
prolonged exposure to steam may reduce the life of your new widget-&-
co cooker hood and is not covered by warranty".

Most extractor manuals say "do not install directly above a hob or
cooking appliance", re temperature & steam.

It does read somewhat peculiarly as you have found :-)

On Apr 15, 12:12*am, "js.b1" wrote:
Most extractor manuals say "do not install directly above a hob or
cooking appliance", re temperature & steam.

That should say "Most extractor FAN (xpelair etc) manuals say"...

On 14/04/2012 22:29, js.b1 wrote:
It is a warranty / liability limitation.
Cooker hoods - switch gear, motor, bearings, impellor are not IP-rated
or temperature-rated for continuous steam exposure. The RCD may trip
out, the motor may run its bearings, the plastic impellor or airflow
guide may melt. Grease could me migrated past the filters via steam
into the motor/impellor assembly creating a fire hazard.

Another point is steam is invisible, viciously hot close to a kettle's
outlet. The visible "steam" is lower temperature hot water vapour. I
suspect plastics used for motor housing, impellor& air ducting may
not be tolerant of continuous high temperature exposure such as when
used in recirculation mode - or even extract mode at low speeds
against a barrage of steam sources. Likewise steam jets from pressure
cookers I think can be a slightly higher temperature.

Most cooker hoods are made by Elica.
Twin motor (320m3/hr) units are good enough to get rid of heat, not
just odours& steam. Single motor (170m3/hr) are good at getting rid
of moisture, they struggle on a hot summer's day. Obviously you can
get single motor 550-800m3/hr units - but check the dB(A) figures
carefully because things can get loud, likewise check hole size.

Ebay sometimes has oddball super high flow hoods at cheap prices, you
do not have to pay the ?£3.5k? someone did per cooker hood on Grand
Designs.

Thanks for that. Nope, not intending to spend loads.

Decided to fall to simple logic of picking something with the highest
flow rate as we are limited to 600mm width.

Noise is her problem and she can do the work in keeping it and the
grease filters clean - the John Lewis model we've found for £200,
filters can be washed. If she fails, I suppose there's the smoke alarm -
where do I dump in Halon gas in that event?



--
Adrian C

On Sun, 15 Apr 2012 20:15:56 +0100, Adrian C wrote:

On 14/04/2012 22:29, js.b1 wrote:
It is a warranty / liability limitation.
Cooker hoods - switch gear, motor, bearings, impellor are not IP-rated
or temperature-rated for continuous steam exposure. The RCD may trip
out, the motor may run its bearings, the plastic impellor or airflow
guide may melt. Grease could me migrated past the filters via steam
into the motor/impellor assembly creating a fire hazard.

Another point is steam is invisible, viciously hot close to a kettle's
outlet. The visible "steam" is lower temperature hot water vapour. I
suspect plastics used for motor housing, impellor& air ducting may
not be tolerant of continuous high temperature exposure such as when
used in recirculation mode - or even extract mode at low speeds
against a barrage of steam sources. Likewise steam jets from pressure
cookers I think can be a slightly higher temperature.

Most cooker hoods are made by Elica.
Twin motor (320m3/hr) units are good enough to get rid of heat, not
just odours& steam. Single motor (170m3/hr) are good at getting rid
of moisture, they struggle on a hot summer's day. Obviously you can
get single motor 550-800m3/hr units - but check the dB(A) figures
carefully because things can get loud, likewise check hole size.

Ebay sometimes has oddball super high flow hoods at cheap prices, you
do not have to pay the ?£3.5k? someone did per cooker hood on Grand
Designs.

Thanks for that. Nope, not intending to spend loads.

Decided to fall to simple logic of picking something with the highest
flow rate as we are limited to 600mm width.

Noise is her problem and she can do the work in keeping it and the
grease filters clean - the John Lewis model we've found for £200,
filters can be washed. If she fails, I suppose there's the smoke alarm -
where do I dump in Halon gas in that event?



is it really a biggy or just curiosity? I;ve never had (nor heard of) an
extractor hood failing from steam of a "normal" domestic kitchen.

Even if it were commonplace which I don;t believe it is, "unfit for
purpose" claims would seem dead certs - IOW WTF would a reasonable person
expect it to be able to do when mounted (as per instructions) above a
cooking appliance??

Jim K

On Apr 15, 8:15*pm, Adrian C wrote:
Noise is her problem and she can do the work in keeping it and the
grease filters clean - the John Lewis model we've found for £200,

JL often give a 2yr warranty, which can be quite useful.

filters can be washed. If she fails, I suppose there's the smoke alarm -
where do I dump in Halon gas in that event?

Fire blanket & 2kg CO2 with frost free horn (55B rated) are good.
Powder makes a piggin awful mess. That is for general DIY use... heh-
heh, just use the kitchen as the reason to buy on the domestic
accounts.

Cooker hoods are excellent at getting grill toast smoke out quickly
(not that I speak from experience, cough... splutter) and there is no
mention against it in the manual of course... unlike the dark force
known as "steam".

Smoke alarms are good at telling you when the oven needs a clean;
quick chirp when you open the door :-)