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.