We intend to put in a large external motor to drive our hood
extraction, in order to cut down on noise as much as possible. Do we
really need to get a "special" hood which can work with an external
motor (hence reducing our options massively), or can we just get any
old hood and remove its existing internal fan and simply run the
ducting direct from hood up and out to the external wall?

I'm assuming a typical island hood just has those washable metal
filters, with a "hole" on the other side in which sits the internal
fan, on the other side of which the ducting starts -- so removing the
fan would just mean having to lower the start of the ducting.

Any thoughts on this? Anyone ever looked inside the mechanisms of
these hoods?

The other complication is that our ceiling is 3.7m, so we'll need to
get a custom-made 2m or so stainless steel box to run up to the
ceiling as well.

thanks for any help,

Vince.

Vince

I would think you have a few options here.

Typically a cooker hood has the motor just below the shroud where the
chimney starts. If placing a new fan in here then you would need to
get one with similar mountings, unless you were to adapt the mounting
plate on the existing hood. If I were you then I would take out the
existing motor, and mount the new motor in the extension piece that
you are getting custom made, this way it can be fabricated as one unit
and perhaps even rubber mounted to reduce vibration noises. I would
also be tempted to do away with the telescoping chimney that comes
with the hood and bring your new hood all the way from the ceiling to
the hood. Ensure the same grade stainless is used throughout. I would
also mount the motor as high up the chimney as possible, or even into
the ceiling since your increase in chimney length will greatly affect
the stability of the whole hood assembly as they are just mounted on a
top ceiling bracket. And a low down motor could cause the assembly to
swing.

You also need to ensure that the new motor that you choose is capable
of taking the 4 wires (live and 3 neutrals for different speed
settings). Alternatively I would imagine that you could link all the
neutrals together so that whatever setting the switch was in, the
motor would just run at its normal speed (check with a sparky on that
one).

FInally, remember that the height from your hob for cooker hoods is a
minimum distance and that especially in islands it is an idea to
increase this distance. This avoids you constantly hitting your head
off it and it blocking your view to the rest of the room.

Hope this helps and good luck.
Calum Sabey
NewArk Traditional Kitchens 01556 690544

On 20 Feb, 00:47, " wrote:
Typically a cookerhoodhas the motor just below the shroud where the
chimney starts. If placing a new fan in here then you would need to
get one with similar mountings, unless you were to adapt the mounting
plate on the existinghood. If I were you then I would take out the
existing motor, and mount the new motor in the extension piece that
you are getting custom made, this way it can be fabricated as one unit
and perhaps even rubber mounted to reduce vibration noises. I would
also be tempted to do away with the telescoping chimney that comes
with thehoodand bring your newhoodall the way from the ceiling to
thehood. Ensure the same grade stainless is used throughout. I would
also mount the motor as high up the chimney as possible, or even into
the ceiling since your increase in chimney length will greatly affect
the stability of the wholehoodassembly as they are just mounted on a
top ceiling bracket. And a low down motor could cause the assembly to
swing.

I was a bit worried about the swinging aspect too!

What you write sounds sensible, and I'm glad to hear you think it'll
work. We were even thinking of mounting the motor at the far end of
the duct (either in the ceiling after the bend in the duct, or even at
the external wall where the duct exits the house).

I think you're right that it will be best to do away with the chimney
that comes with the hood, and just put in a solidly-constructed new
chimney in one piece.

You also need to ensure that the new motor that you choose is capable
of taking the 4 wires (live and 3 neutrals for different speed
settings). Alternatively I would imagine that you could link all the
neutrals together so that whatever setting the switch was in, the
motor would just run at its normal speed (check with a sparky on that
one).

That's a good point and a good idea -- that we don't have to have
something that runs at lots of different speeds if that makes it hard
to get the right motor.

FInally, remember that the height from your hob for cooker hoods is a
minimum distance and that especially in islands it is an idea to
increase this distance. This avoids you constantly hitting your head
off it and it blocking your view to the rest of the room.

I'd thought about the hitting your head bit, but not about the view --
that's definitely also important. I think we should probably mount at
1.9m above the floor, or perhaps 2m -- I'll have to visit some more
kitchen shops to help visualise things better.

Thanks for your advice - truly very helpful.

Vince.

Vince
Its good to know that there is some food for thought. I wouldnt worry
too much about raising it too high off the ground. Forehead height
should be high enough since you never want to look up, only down or
straight across and this should be high enough so that when you bend
over the worktop your head misses the hood. Its always a play off
between it extracting well and it not getting in the way.

Another option is to do away witht the hood altogether and have an
extraction motor in the ceiling with a large skirt at ceiling height
to encourage smells and vapour to go into the extraction unit rather
than the rest of the house... I know this sounds like a weird idea but
it actually looks really good when done properly, give me a call if
you want it explained fuller or want some pics of what I mean.

Also if you need any further help or advice then just pick up the
phone and leave a message if i'm not in.

Calum Sabey
NewArk Traditional Kitchens 01556 690544