Just fitted the bathroom extractor - vent in ceiling, fan in loft, with a humidistat and all is good. I have two backdraught dampers, a gravity one in the vertical section and a sprung one in the horizontal section and there are a bends in both planes so no direct route for wind. There is a slight coldness around the vent and external noise can be heard which is not surprising. However it made me realise what I really want is a powered damper that seals in an airtight manner. Googling does not find much.
Any ideas of where to get one, or how to make one, for a sensible cost ?

Simon.

sm_jamieson wrote

Just fitted the bathroom extractor - vent in ceiling, fan in loft,
with a humidistat and all is good. I have two backdraught
dampers, a gravity one in the vertical section and a sprung
one in the horizontal section and there are a bends in both
planes so no direct route for wind. There is a slight coldness
around the vent and external noise can be heard which is
not surprising. However it made me realise what I really
want is a powered damper that seals in an airtight manner.

Googling does not find much.

You must be using the wrong keywords
www.google.com/search?q=exhaust+fan+shutter

Any ideas of where to get one, or
how to make one, for a sensible cost ?

I wouldn't bother to make one myself.

In article ,
sm_jamieson writes:
Just fitted the bathroom extractor - vent in ceiling, fan in loft, with a humidistat and all is good. I have two backdraught dampers, a gravity one in the vertical section and a sprung one in the horizontal section and there are a bends in both planes so no direct route for wind. There is a slight coldness around the vent and external noise can be heard which is not surprising. However it made me realise what I really want is a powered damper that seals in an airtight manner. Googling does not find much.
Any ideas of where to get one, or how to make one, for a sensible cost ?

Search for extractor fan with shutter.
They aren't cheap.

I have a few, but they're old.
A 6" Vent Axia which has solenoid operated shutter, which operates with
quite a loud bang at both switch-on and switch-off.
A couple of 4" Deta extractors which have thermo-electric solenoids which
open and close very slowly (and silently) as the solenoid self-heats and
cools. Note that as thermo-electric solenoids take a few minutes to close
after the fan is switched off, you can get a backdraft for a short time.

Neither of these products are still around (Deta themselves folded some
years ago, sadly), but you can find fans with powered shutters.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Wednesday, December 17, 2014 9:29:48 PM UTC, Rod Speed wrote:
sm_jamieson wrote

Just fitted the bathroom extractor - vent in ceiling, fan in loft,
with a humidistat and all is good. I have two backdraught
dampers, a gravity one in the vertical section and a sprung
one in the horizontal section and there are a bends in both
planes so no direct route for wind. There is a slight coldness
around the vent and external noise can be heard which is
not surprising. However it made me realise what I really
want is a powered damper that seals in an airtight manner.

Googling does not find much.

You must be using the wrong keywords
www.google.com/search?q=exhaust+fan+shutter

Any ideas of where to get one, or
how to make one, for a sensible cost ?

I wouldn't bother to make one myself.

Sorry, I mean an inline device to put in the ducting. I know there are hole-in-wall extractors with powered flaps - but I doubt those are actually airtight.
Simon.

On Wednesday, December 17, 2014 9:35:35 PM UTC, Andrew Gabriel wrote:
In article ,
sm_jamieson writes:
Just fitted the bathroom extractor - vent in ceiling, fan in loft, with a humidistat and all is good. I have two backdraught dampers, a gravity one in the vertical section and a sprung one in the horizontal section and there are a bends in both planes so no direct route for wind. There is a slight coldness around the vent and external noise can be heard which is not surprising. However it made me realise what I really want is a powered damper that seals in an airtight manner. Googling does not find much.
Any ideas of where to get one, or how to make one, for a sensible cost ?

Search for extractor fan with shutter.
They aren't cheap.

I have a few, but they're old.
A 6" Vent Axia which has solenoid operated shutter, which operates with
quite a loud bang at both switch-on and switch-off.
A couple of 4" Deta extractors which have thermo-electric solenoids which
open and close very slowly (and silently) as the solenoid self-heats and
cools. Note that as thermo-electric solenoids take a few minutes to close
after the fan is switched off, you can get a backdraft for a short time.

Neither of these products are still around (Deta themselves folded some
years ago, sadly), but you can find fans with powered shutters.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

It was an inline ducting damper required. The through-the-wall fans might be better than they used to be, but I always remember my mum's one rattling away.

Something from the US,

http://www.smarthome.com/suncourt-zo106-6-inch-diameter-normally-open-electronic-hvac-air-duct-damper-with-power-supply.html

Looks fairly basic so I'm not sure how well it would seal - airtight is the aim, to avoid noise transfer as well as better immunity from draughts.
I guess such things would be available from aircon suppliers in the UK, but the "HVAC" industry is of course much larger in the US.

Simon.

sm_jamieson presented the following explanation :
Sorry, I mean an inline device to put in the ducting. I know there are
hole-in-wall extractors with powered flaps - but I doubt those are actually
airtight.
Simon.

The one we have in our bathroom extractor fan is fairly airtight. It
operates via a wax cartridge expanding, when heated. Rather like the
waxstat thermostat they sold for car cooling systems.

It has an electric heating element, to heat the wax, the cartridge
expands, pushes on a sprung lever to open an iris type shutter
arrangement as you used to see on cameras. It takes around 30 seconds
to fully open, from fan switch on, then a couple of minutes to re-close
after switch off. Wax expansion is a very powerful force.

The other type of extractor shutter arrangement, uses a solenoid, which
makes a loud bang as it opens and closes. The wax type is almost
silent.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Andrew Gabriel laid this down on his screen :
A couple of 4" Deta extractors which have thermo-electric solenoids which
open and close very slowly (and silently) as the solenoid self-heats and
cools.

It is not a solenoid, it is a wax cartridge which expands and contracts
when heated and cools.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

sm_jamieson wrote
Rod Speed wrote
sm_jamieson wrote

Just fitted the bathroom extractor - vent in ceiling, fan in loft,
with a humidistat and all is good. I have two backdraught
dampers, a gravity one in the vertical section and a sprung
one in the horizontal section and there are a bends in both
planes so no direct route for wind. There is a slight coldness
around the vent and external noise can be heard which is
not surprising. However it made me realise what I really
want is a powered damper that seals in an airtight manner.

Googling does not find much.

You must be using the wrong keywords
www.google.com/search?q=exhaust+fan+shutter

Any ideas of where to get one, or
how to make one, for a sensible cost ?

I wouldn't bother to make one myself.

Sorry, I mean an inline device to put in the ducting.

OK, but I don't see why you need one of those.

I know there are hole-in-wall extractors with powered
flaps - but I doubt those are actually airtight.

Not sure they need to be airtight with a ducted system.

It shouldn't be that hard to DIY with a round one
with a decent soft rubber seal around the edges
driven by a motor with an end cutoff like you get
with car windows or even just a stepper motor.
Sort of like a very large gate valve with a decent
soft round seal like you get with front loading
washing machines.

sm_jamieson wrote
Andrew Gabriel wrote
sm_jamieson wrote

Just fitted the bathroom extractor - vent in ceiling,
fan in loft, with a humidistat and all is good. I have
two backdraught dampers, a gravity one in the vertical
section and a sprung one in the horizontal section and
there are a bends in both planes so no direct route for
wind. There is a slight coldness around the vent and
external noise can be heard which is not surprising.
However it made me realise what I really want is a
powered damper that seals in an airtight manner.
Googling does not find much.

Any ideas of where to get one, or how
to make one, for a sensible cost ?

Search for extractor fan with shutter.
They aren't cheap.

I have a few, but they're old.

A 6" Vent Axia which has solenoid operated shutter, which
operates with quite a loud bang at both switch-on and switch-off.

A couple of 4" Deta extractors which have thermo-electric solenoids which
open and close very slowly (and silently) as the solenoid self-heats and
cools. Note that as thermo-electric solenoids take a few minutes to close
after the fan is switched off, you can get a backdraft for a short time.

Neither of these products are still around (Deta themselves folded
some years ago, sadly), but you can find fans with powered shutters.

It was an inline ducting damper required. The through-the-wall
fans might be better than they used to be, but I always remember
my mum's one rattling away.

The one I have on the kitchen exhaust fan doesn't rattle
at all. Goes off with a hell of a bang when you turn the
fan on tho. The parent's new house built in the very
early 70s was even more dramatic and loud.

Something from the US,

http://www.smarthome.com/suncourt-zo...er-supply.html

Looks fairly basic so I'm not sure how well it would seal - airtight is
the aim,

Still not convinced that that is necessary.

to avoid noise transfer

I don't get any noise transfer thru my kitchen exhaust
fan which faces onto the next doo neighbour's area
where their grandkids do play quite noisily at times.

as well as better immunity from draughts.

I don't get any draughts from mine.

I guess such things would be available from aircon suppliers in
the UK, but the "HVAC" industry is of course much larger in the US.

No reason why you can't import one and change the motor.

On Thursday, December 18, 2014 7:18:24 PM UTC, Rod Speed wrote:
sm_jamieson wrote
Something from the US,

http://www.smarthome.com/suncourt-zo...er-supply.html

Looks fairly basic so I'm not sure how well it would seal - airtight is
the aim,

Still not convinced that that is necessary.

to avoid noise transfer

I don't get any noise transfer thru my kitchen exhaust
fan which faces onto the next doo neighbour's area
where their grandkids do play quite noisily at times.

as well as better immunity from draughts.

I don't get any draughts from mine.

I guess such things would be available from aircon suppliers in
the UK, but the "HVAC" industry is of course much larger in the US.

No reason why you can't import one and change the motor.

Its not clear if you have a ducted fan or a through the wall device. I have always avoided through the wall since they used to have very poor extraction rates - but maybe they are better now.
I have always thought a nice vent in the ceiling and an inline duct fan is the best solution so that is what I fitted. I have two backdraught dampers, one gravity and one sprung, the pipework has a few bends in it and the vent exits downwards from the soffit.
If there is any air path you will always get some noise coming through, and standard inlne backdraught shutters are not airtight. The effect I am getting is as if a trickle vent has been opened or the double glazing does not quite seal properly - the slight roar of distant traffic, etc. This is one area where a through the wall fan with well sealing shutters could be better, but the ultimate solution for a ducted fan is an air tight damper in the ducting. Not a major deal, but as an engineer I like to find solutions !
Simon.

sm_jamieson wrote
Rod Speed wrote
sm_jamieson wrote

Something from the US,

http://www.smarthome.com/suncourt-zo...er-supply.html

Looks fairly basic so I'm not sure how
well it would seal - airtight is the aim,

Still not convinced that that is necessary.

to avoid noise transfer

I don't get any noise transfer thru my kitchen exhaust
fan which faces onto the next doo neighbour's area
where their grandkids do play quite noisily at times.

as well as better immunity from draughts.

I don't get any draughts from mine.

I guess such things would be available from aircon suppliers in
the UK, but the "HVAC" industry is of course much larger in the US.

No reason why you can't import one and change the motor.

Don't actually need to change the motor, it's a 24V motor.

Its not clear if you have a ducted fan or a through the wall device.

I have a thru the wall exhaust fan, but since I don't get any draughts
with that or noise thru it either, one of those shutters on the room
end of a duct should work even better with a duct because of the duct.

I have always avoided through the wall since they used to have
very poor extraction rates - but maybe they are better now.

Mine is more than 40 years old and has always had one hell of an extraction
rate.

I have always thought a nice vent in the ceiling and an inline duct fan is
the best solution

I decided it wasn't, essentially because I have the exhaust fan over the
sheet of glass top hotplates set into a hole in the massive great 20'
long bench that is all down one side of the kitchen against the wall
with the hotplates roughly half way down that, all counterleavered
off the wall with cupboards, dishwashers, bar fridge sized freezers
all sliding in under that. I did intend to have cupboards above that
very long bench with what would be effectively a range hood over
the cooktop but later decided against that, mainly because access
to the contents of cupboards there isnt very convenient at all.

Turned out that the main need for the exhaust fan is when grilling
in the grill under the wall oven at the end of that very long bench
but it actually works pretty well there for that.

so that is what I fitted. I have two backdraught dampers, one gravity and
one sprung,
the pipework has a few bends in it and the vent exits downwards from the
soffit.

That's the main reason I didn't go that route, I decided that the
duct would result in much worse air flow with the fan running.

And its mechanically much more awkward too. That wall the
exhaust fan is in is the main external block wall so all I had to
do is do a big square hole in the block work when laying the
blocks and put the fan in that hole. The outside end just has
a plastic grill with screws into rawplugs in the blocks. Very simple.

If there is any air path you will always get some noise coming through,

I don't in fact as I said.

and standard inlne backdraught shutters are not airtight.

Yet I don't get a draught there. So the shutter is essentially air tight
enough.

And its very handy to be able to unscrew the two screws in the
bottom edge of the shutter surround and put the whole thing
in the dishwasher given that it gets absolutely filthy because of
the fat from the grilling ending up on it and collecting dust on it.

Same with the outside one.

The effect I am getting is as if a trickle vent has been opened or the
double
glazing does not quite seal properly - the slight roar of distant traffic,
etc.

Don't get any traffic roar here but I do have the neighbours grandkids
romping around and shouting at each other just the other side of that
wall and that doesn't come thru the exhaust fan.

This is one area where a through the wall fan with well sealing shutters
could
be better, but the ultimate solution for a ducted fan is an air tight
damper in
the ducting. Not a major deal, but as an engineer I like to find solutions
!

Yeah, I do too and in fact I designed the entire house from scratch
and physically built it all myself as well on a bare block of land.

On Thursday, December 18, 2014 9:44:27 PM UTC, Rod Speed wrote:
sm_jamieson wrote
Rod Speed wrote
sm_jamieson wrote

Something from the US,

http://www.smarthome.com/suncourt-zo...er-supply.html

Looks fairly basic so I'm not sure how
well it would seal - airtight is the aim,

Still not convinced that that is necessary.

to avoid noise transfer

I don't get any noise transfer thru my kitchen exhaust
fan which faces onto the next doo neighbour's area
where their grandkids do play quite noisily at times.

as well as better immunity from draughts.

I don't get any draughts from mine.

I guess such things would be available from aircon suppliers in
the UK, but the "HVAC" industry is of course much larger in the US.

No reason why you can't import one and change the motor.

Don't actually need to change the motor, it's a 24V motor.

Its not clear if you have a ducted fan or a through the wall device.

I have a thru the wall exhaust fan, but since I don't get any draughts
with that or noise thru it either, one of those shutters on the room
end of a duct should work even better with a duct because of the duct.

I have always avoided through the wall since they used to have
very poor extraction rates - but maybe they are better now.

Mine is more than 40 years old and has always had one hell of an extraction
rate.

I have always thought a nice vent in the ceiling and an inline duct fan is
the best solution

I decided it wasn't, essentially because I have the exhaust fan over the
sheet of glass top hotplates set into a hole in the massive great 20'
long bench that is all down one side of the kitchen against the wall
with the hotplates roughly half way down that, all counterleavered
off the wall with cupboards, dishwashers, bar fridge sized freezers
all sliding in under that. I did intend to have cupboards above that
very long bench with what would be effectively a range hood over
the cooktop but later decided against that, mainly because access
to the contents of cupboards there isnt very convenient at all.

Turned out that the main need for the exhaust fan is when grilling
in the grill under the wall oven at the end of that very long bench
but it actually works pretty well there for that.

so that is what I fitted. I have two backdraught dampers, one gravity and
one sprung,
the pipework has a few bends in it and the vent exits downwards from the
soffit.

That's the main reason I didn't go that route, I decided that the
duct would result in much worse air flow with the fan running.

And its mechanically much more awkward too. That wall the
exhaust fan is in is the main external block wall so all I had to
do is do a big square hole in the block work when laying the
blocks and put the fan in that hole. The outside end just has
a plastic grill with screws into rawplugs in the blocks. Very simple.

If there is any air path you will always get some noise coming through,

I don't in fact as I said.

and standard inlne backdraught shutters are not airtight.

Yet I don't get a draught there. So the shutter is essentially air tight
enough.

And its very handy to be able to unscrew the two screws in the
bottom edge of the shutter surround and put the whole thing
in the dishwasher given that it gets absolutely filthy because of
the fat from the grilling ending up on it and collecting dust on it.

Same with the outside one.

The effect I am getting is as if a trickle vent has been opened or the
double
glazing does not quite seal properly - the slight roar of distant traffic,
etc.

Don't get any traffic roar here but I do have the neighbours grandkids
romping around and shouting at each other just the other side of that
wall and that doesn't come thru the exhaust fan.

This is one area where a through the wall fan with well sealing shutters
could
be better, but the ultimate solution for a ducted fan is an air tight
damper in
the ducting. Not a major deal, but as an engineer I like to find solutions
!

Yeah, I do too and in fact I designed the entire house from scratch
and physically built it all myself as well on a bare block of land.

I built an extension all myself. I'd love to do a house but I'd have to get someone in as my back is not up to it (oh and win the lottery !). Land is expensive in UK.
A Georgian style house with 10 foot ceilings (that's high enough) built around a wide hallway running from front to back with big oak double doors at each end (for a nice wind tunnel in the summer). Several reception rooms around 8 x 6m each and nice fireplaces. Easy Peasy !
Simon.

sm_jamieson wrote
Rod Speed wrote
sm_jamieson wrote
Rod Speed wrote
sm_jamieson wrote

Something from the US,

http://www.smarthome.com/suncourt-zo...er-supply.html

Looks fairly basic so I'm not sure how
well it would seal - airtight is the aim,

Still not convinced that that is necessary.

to avoid noise transfer

I don't get any noise transfer thru my kitchen exhaust
fan which faces onto the next doo neighbour's area
where their grandkids do play quite noisily at times.

as well as better immunity from draughts.

I don't get any draughts from mine.

I guess such things would be available from aircon suppliers in
the UK, but the "HVAC" industry is of course much larger in the US.

No reason why you can't import one and change the motor.

Don't actually need to change the motor, it's a 24V motor.

Its not clear if you have a ducted fan or a through the wall device.

I have a thru the wall exhaust fan, but since I don't get any draughts
with that or noise thru it either, one of those shutters on the room
end of a duct should work even better with a duct because of the duct.

I have always avoided through the wall since they used to have
very poor extraction rates - but maybe they are better now.

Mine is more than 40 years old and has always had one hell of an
extraction rate.

I have always thought a nice vent in the ceiling
and an inline duct fan is the best solution

I decided it wasn't, essentially because I have the exhaust fan over the
sheet of glass top hotplates set into a hole in the massive great 20'
long bench that is all down one side of the kitchen against the wall
with the hotplates roughly half way down that, all counterleavered
off the wall with cupboards, dishwashers, bar fridge sized freezers
all sliding in under that. I did intend to have cupboards above that
very long bench with what would be effectively a range hood over
the cooktop but later decided against that, mainly because access
to the contents of cupboards there isnt very convenient at all.

Turned out that the main need for the exhaust fan is when
grilling in the grill under the wall oven at the end of that very
long bench but it actually works pretty well there for that.

so that is what I fitted. I have two backdraught dampers,
one gravity and one sprung, the pipework has a few
bends in it and the vent exits downwards from the soffit.

That's the main reason I didn't go that route, I decided that the
duct would result in much worse air flow with the fan running.

And its mechanically much more awkward too. That wall the
exhaust fan is in is the main external block wall so all I had to
do is do a big square hole in the block work when laying the
blocks and put the fan in that hole. The outside end just has
a plastic grill with screws into rawplugs in the blocks. Very simple.

If there is any air path you will always get some noise coming through,

I don't in fact as I said.

and standard inlne backdraught shutters are not airtight.

Yet I don't get a draught there. So the
shutter is essentially air tight enough.

And its very handy to be able to unscrew the two screws in the
bottom edge of the shutter surround and put the whole thing
in the dishwasher given that it gets absolutely filthy because of
the fat from the grilling ending up on it and collecting dust on it.

Same with the outside one.

The effect I am getting is as if a trickle vent has been
opened or the double glazing does not quite seal
properly - the slight roar of distant traffic, etc.

Don't get any traffic roar here but I do have the neighbours grandkids
romping around and shouting at each other just the other side of that
wall and that doesn't come thru the exhaust fan.

This is one area where a through the wall fan with well sealing
shutters could be better, but the ultimate solution for a ducted
fan is an air tight damper in the ducting. Not a major deal, but
as an engineer I like to find solutions !

Yeah, I do too and in fact I designed the entire house from scratch
and physically built it all myself as well on a bare block of land.

I built an extension all myself. I'd love to do a house

Yeah, it leaves the other DIY projects for dead.

but I'd have to get someone in as my back is not up to it

Never had a back problem myself.

(oh and win the lottery !).

I in fact ended up making a lot more than the boss
of the place I worked for at the time did essentially
because with our tax system it was all tax free because
capital gains on the primary residence is tax free.

Land is expensive in UK.

Its not cheap here now either. I only paid $3750 for it
in the very early 70s and you were free to pay it off at
a very low interest instead of paying a lump sum too.

Today blocks just down the road are typically $150K
and its money up front too.

A Georgian style house

Mine is modern style, flat roof, passive solar with 13
massive great patio doors which are the only thing
in all the bedrooms and the two main rooms. The
only conventional windows are in the bathrooms
and toilets and kitchens.

with 10 foot ceilings (that's high enough)

I did go one more block row above the legal minimum so 8'8"

built around a wide hallway running from front to back

Mine is open plan hardly any hallway at all, just a short
one down the side one bedroom to the two bedrooms
at one end of the house and one between the cluster
of bathrooms and toilets in the middle of the house
between the two main rooms. The place is designed
so you can have a solid wall there between the cluster
of bathrooms and toilets and have two very large flats
instead of the one big house. Never did bother to do
that tho, use the whole very large house.

with big oak double doors at each end
(for a nice wind tunnel in the summer).

I have the massive patio doors on the N and S
side of the main rooms, 5 on the biggest main
room, 3 on the smaller one. Gives very nice
outside inside result in the spring and autumn
with all the doors open.

Our summers are too hot for that to be enough
tho, we can have 10 days over 40C in a row so
what the yanks call a swap cooler is essential.

Several reception rooms around 8 x 6m each

I just have the two very large open plan areas.

and nice fireplaces.

Mine is passive solar and otherwise electric heating, heatbank.

Easy Peasy !

Yeah, leaves other DIY for dead. You get to use it all the time.