my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep

"davep" wrote in message
...
my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep

From our experience you'd be better with some form of extra ventilation but
you don't need to haveanythingcomplicated like aceiling fan and ducting if
you already have thehole in thewall. .

At the suggestion of someone here we've recently replaced the inefficient
extractor fan in the hole with a low wattage rh sensitive automatic fan. It
works very efficiently (and very quietly) and we don't have to think of
switching it on or off - although we can if we want.

We're getting idle in our dotage :-)

Mary

Mary Fisher wrote:

"davep" wrote in message
...


my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep



From our experience you'd be better with some form of extra ventilation but
you don't need to haveanythingcomplicated like aceiling fan and ducting if
you already have thehole in thewall. .

At the suggestion of someone here we've recently replaced the inefficient
extractor fan in the hole with a low wattage rh sensitive automatic fan. It
works very efficiently (and very quietly) and we don't have to think of
switching it on or off - although we can if we want.

We're getting idle in our dotage :-)

Mary




thanks for the reply.
I'm mainly concerned from a building regs perspective.
An electrician friend has said I need one,
connected to lighting loop with fused outlet outside

my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?

Replace the fixed vent with a fan. Job done. You can put ducted stuff in the
loft if you want, but just reusing the existing hole will be quicker,
cheaper and more effective.

Christian.

Christian McArdle wrote:

my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?



Replace the fixed vent with a fan. Job done. You can put ducted stuff in the
loft if you want, but just reusing the existing hole will be quicker,
cheaper and more effective.

Christian.




the fixed vent is within zone 1. okay I can use a product
that is IPX4 or selv but I don't think I can run this
from the lighting loop.
What I really need to know is whether in fact a fan is necessary.
davep

"davep" wrote in message
...
Mary Fisher wrote:

"davep" wrote in message
.. .

my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep


From our experience you'd be better with some form of extra ventilation
but you don't need to haveanythingcomplicated like aceiling fan and
ducting if you already have thehole in thewall. .

At the suggestion of someone here we've recently replaced the inefficient
extractor fan in the hole with a low wattage rh sensitive automatic fan.
It works very efficiently (and very quietly) and we don't have to think
of switching it on or off - although we can if we want.

We're getting idle in our dotage :-)

Mary


thanks for the reply.
I'm mainly concerned from a building regs perspective.
An electrician friend has said I need one,
connected to lighting loop with fused outlet outside

?

That only applies if you want the fan to come on every time you switch on
the light - and only when you switch on the light, even during the day. We
didn't want that so ours is independently wired. It makes sense in many
ways. Power saving is themost important one.

Mary

On Fri, 21 Apr 2006 10:34:39 +0100, davep
wrote:

|my average 3 bed semi has a bathroom with two outside
|walls. It has a 9" sq hole with vents to the outside.
|Do I need to supply extra ventilation
|in the form of a ceiling fan and ducting
|in the loft?

I have had no problems with *two* square inches ventilation in my bathroom.
Average semi, four adults.
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
newsreader, say Agent, and a newsserver, say news.individual.net. These
will allow them: to see only *new* posts, a killfile, and other goodies.

On Fri, 21 Apr 2006 11:04:04 +0100 someone who may be davep
wrote this:-

I'm mainly concerned from a building regs perspective.

They are not retrospective. If you were to do a lot of work on the
house then a fan might become "necessary" under the building
regulations, though since you didn't say where you are it is
difficult to go much further.

Does the bathroom have a window? If so, does this not provide
adequate ventilation without making your electricity meter go round?

An electrician friend has said I need one,
connected to lighting loop with fused outlet outside

Three incorrect statements.

Sadly, mechanical ventilation is required in places for new
buildings (and perhaps extensive works), but not retrospectively in
existing buildings.

Mechanical ventilation can be fitted to any suitable circuit,
providing that this is done properly. That could be a lighting
circuit, or not a lighting circuit.

Fused connection units can be placed inside a bathroom, provided
they are in the correct places, or outside.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

I have had no problems with *two* square inches ventilation in my
bathroom.
Average semi, four adults.

Teenage girls? That's when you get condensation.

Christian.

In message , davep
writes
Christian McArdle wrote:

my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?


Replace the fixed vent with a fan. Job done. You can put ducted stuff in the
loft if you want, but just reusing the existing hole will be quicker,
cheaper and more effective.

Christian.



the fixed vent is within zone 1. okay I can use a product
that is IPX4 or selv but I don't think I can run this
from the lighting loop.

Why not?

What I really need to know is whether in fact a fan is necessary.

As has been pointed out probably not from the POV of building regs.

Only you are in a position to judge whether the bathroom ventilation
needs improving.
--
Chris French

The message
from "Christian McArdle" contains
these words:

Teenage girls? That's when you get condensation.

And teenage boys, when they discover girls.

--
Skipweasel
Pay no attention to that man behind the curtain.

If its new work ie forming a bathroom for the first time then a fan is
required if its an existing bathroom then no mech extract is required

If its new work ie forming a bathroom for the first time then a fan is
required if its an existing bathroom then no mech extract is required

If its new work ie forming a bathroom for the first time then a fan is
required if its an existing bathroom then no mech extract is required

"surveyor" wrote in message
ups.com...
If its new work ie forming a bathroom for the first time then a fan is
required if its an existing bathroom then no mech extract is required

It might not be required by The Authorities but often it's desirable.

Mary

davep wrote on 21/04/2006 :
my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep

The hole sounds excessively large for what I would guess is quite a
small bathroom.

The best solution would be to install a small extract fan in the
existing hole, a 4" or at most 6" fan would probably be adequate. This
would draw air in from the rest of the house -helping to prevent the
moist air spreading out from the bathroom - rather than having a
drafty, open 9" square hole. You would also need to ensure all of the
extracted air went straight out through the wall, rather than into any
wall cavity there might be.

The best type to install are the ones with an automatic shutter,
triggered by humidity and by PIR with delay timer. That means it would
turn itself on if someone were to walk in and keep running for a set
period, or keep running until the humidity falls to normal levels if
someone has had a bath/shower.

Much better than the ones which need the light to be turned on before
it will operate, as you don't normally turn the light on during the day
when using the bathroom.

--

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

davep wrote:
Mary Fisher wrote:

"davep" wrote in message
...


my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep



From our experience you'd be better with some form of extra ventilation but
you don't need to haveanythingcomplicated like aceiling fan and ducting if
you already have thehole in thewall. .

At the suggestion of someone here we've recently replaced the inefficient
extractor fan in the hole with a low wattage rh sensitive automatic fan. It
works very efficiently (and very quietly) and we don't have to think of
switching it on or off - although we can if we want.

We're getting idle in our dotage :-)

Mary




thanks for the reply.
I'm mainly concerned from a building regs perspective.
An electrician friend has said I need one,
connected to lighting loop with fused outlet outside

If you have outside walls then you certainly don't need ducting to go
through your roof, that's when you don't have any outside walls and no
other option but to.

"Harry Bloomfield" wrote in message
...

The best type to install are the ones with an automatic shutter, triggered
by humidity and by PIR with delay timer. That means it would turn itself
on if someone were to walk in

Why on Earth would you need the fan to turn on just because someone walks
in? Do you have one in other rooms in the house???

The best automatic one is goverened by humidity, not movement..

Mary

davep wrote:
Mary Fisher wrote:

"davep" wrote in message
...


my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep


From our experience you'd be better with some form of extra
ventilation but you don't need to haveanythingcomplicated like
aceiling fan and ducting if you already have thehole in thewall. .

At the suggestion of someone here we've recently replaced the
inefficient extractor fan in the hole with a low wattage rh sensitive
automatic fan. It works very efficiently (and very quietly) and we
don't have to think of switching it on or off - although we can if we
want.

We're getting idle in our dotage :-)

Mary



thanks for the reply.
I'm mainly concerned from a building regs perspective.
An electrician friend has said I need one,
connected to lighting loop with fused outlet outside

He is largely correct. Slap a fan in the hole in the wall. The ouside
bit is not fused, its merely a double pole isolator.

You can choose between things that run off the lights direct., with a
timer, or a humidity sensor, or combinations of these.
Whilst you are at it, insulate the outside walls..if you can..

Mary Fisher wrote:
"davep" wrote in message
...
Mary Fisher wrote:

"davep" wrote in message
...

my average 3 bed semi has a bathroom with two outside
walls. It has a 9" sq hole with vents to the outside.
Do I need to supply extra ventilation
in the form of a ceiling fan and ducting
in the loft?
davep

From our experience you'd be better with some form of extra ventilation
but you don't need to haveanythingcomplicated like aceiling fan and
ducting if you already have thehole in thewall. .

At the suggestion of someone here we've recently replaced the inefficient
extractor fan in the hole with a low wattage rh sensitive automatic fan.
It works very efficiently (and very quietly) and we don't have to think
of switching it on or off - although we can if we want.

We're getting idle in our dotage :-)

Mary


thanks for the reply.
I'm mainly concerned from a building regs perspective.
An electrician friend has said I need one,
connected to lighting loop with fused outlet outside

?

That only applies if you want the fan to come on every time you switch on
the light - and only when you switch on the light, even during the day. We
didn't want that so ours is independently wired. It makes sense in many
ways. Power saving is themost important one.

Mary


The regs say that electrical kit in bathrooms must be connected to a
double pole isolator outside - or outside the zone anyway IIRC.

Whether that is on the light circuit, switched by the light switch, or
what, is up to you.

David Hansen wrote:
On Fri, 21 Apr 2006 11:04:04 +0100 someone who may be davep
wrote this:-

I'm mainly concerned from a building regs perspective.

They are not retrospective. If you were to do a lot of work on the
house then a fan might become "necessary" under the building
regulations, though since you didn't say where you are it is
difficult to go much further.

Does the bathroom have a window? If so, does this not provide
adequate ventilation without making your electricity meter go round?

An electrician friend has said I need one,
connected to lighting loop with fused outlet outside

Three incorrect statements.

Sadly, mechanical ventilation is required in places for new
buildings (and perhaps extensive works), but not retrospectively in
existing buildings.

Mechanical ventilation can be fitted to any suitable circuit,
providing that this is done properly. That could be a lighting
circuit, or not a lighting circuit.

Fused connection units can be placed inside a bathroom, provided
they are in the correct places, or outside.


However building regulations do apply to any 'material change' so if
doing a rewire, it is arguable that they do apply to all electrical
*fittings*.

"The Natural Philosopher" wrote in message
...


The regs say that electrical kit in bathrooms must be connected to a
double pole isolator outside - or outside the zone anyway IIRC.

Yes.

Whether that is on the light circuit, switched by the light switch, or
what, is up to you.

Yes.

But it doesn't make sense to have it controlled by the light switch, wasting
power when you go into the bathroom during the day.

Today is Earth Day.

Mary Fisher wrote:

Today is Earth Day.

Solar powered searches for one day only[1] :-)
http://www.google.com/logos/earthday06.gif

[1] Apart from fact that the entire solar system is, well errm, solar
powered every other day too, but YKWIM ..

"Andy Burns" wrote in message
...
Mary Fisher wrote:

Today is Earth Day.

Solar powered searches for one day only[1] :-)
http://www.google.com/logos/earthday06.gif

[1] Apart from fact that the entire solar system is, well errm, solar
powered every other day too, but YKWIM ..

I do. And isn't it a clever Google! Mind you, they mostly are.

Mary

The message
from "Mary Fisher" contains these words:

But it doesn't make sense to have it controlled by the light switch,
wasting
power when you go into the bathroom during the day.

Except in the case of our downstairs loo[1] which has a PIR controlled
light so visiting kids don't get all panicky when they shut the door and
only then realise it's utterly dark inside.

[1] Known as the sidraT 'cos unlike the Tardis it's a lot smaller inside
than you expect. Even smaller than HDV's, and doesn't have a priest-hole
like hers.

--
Skipweasel
Pay no attention to that man behind the curtain.

"Guy King" wrote in message
...
The message
from "Mary Fisher" contains these words:

But it doesn't make sense to have it controlled by the light switch,
wasting
power when you go into the bathroom during the day.

Except in the case of our downstairs loo[1] which has a PIR controlled
light so visiting kids don't get all panicky when they shut the door and
only then realise it's utterly dark inside.

Teach them how to use the switch :-)

But the question was about a BATHroom, no mention was madeof a wc.

Not that I think it's necessary to have an extractor fan in the lav, we
don't, just the wall ventilator brick. It's not a problem now and wasn't
when five offspring lived here or when we have people staying.

Mary

It happens that Mary Fisher formulated :
Why on Earth would you need the fan to turn on just because someone walks in?
Do you have one in other rooms in the house???

The best automatic one is goverened by humidity, not movement..

A humidity sensor only would mean it would only be actuated by use of
bath or shower. I assume you also have a toilet in your bathroom and
the need to remove smells after its use? The PIR copes with that need.

--

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

"Harry Bloomfield" wrote in message
...
It happens that Mary Fisher formulated :
Why on Earth would you need the fan to turn on just because someone walks
in? Do you have one in other rooms in the house???

The best automatic one is goverened by humidity, not movement..

A humidity sensor only would mean it would only be actuated by use of bath
or shower. I assume you also have a toilet in your bathroom

No.

and the need to remove smells after its use?

No.

The PIR copes with that need.

As I said, the op asked about a bathrom, not a lavatory.

Mary

The message
from "Mary Fisher" contains these words:

Except in the case of our downstairs loo[1] which has a PIR controlled
light so visiting kids don't get all panicky when they shut the door and
only then realise it's utterly dark inside.

Teach them how to use the switch :-)

That's great if they're your own kids, but there's times when there's
half a dozen ectopic sprogs hurtling around. Several times they got into
the downstairs loo and had major wobblies as a result. The lock's also
one of those that can be opened from the outside if needed - which I
reckon's a good idea on pretty well all lockable internal doors - plenty
of privacy but access when needed in an emergency.

--
Skipweasel
Pay no attention to that man behind the curtain.

"Guy King" wrote in message
...
The message
from "Mary Fisher" contains these words:

Except in the case of our downstairs loo[1] which has a PIR controlled
light so visiting kids don't get all panicky when they shut the door
and
only then realise it's utterly dark inside.

Teach them how to use the switch :-)

That's great if they're your own kids, but there's times when there's
half a dozen ectopic sprogs hurtling around. Several times they got into
the downstairs loo and had major wobblies as a result. The lock's also
one of those that can be opened from the outside if needed - which I
reckon's a good idea on pretty well all lockable internal doors - plenty
of privacy but access when needed in an emergency.

I don't know how people survived without modern technology.

er - did you really mean ectopic?

Mary

The message
from "Mary Fisher" contains these words:

er - did you really mean ectopic?

Yeeah - they're out of place - ie. in mine.

--
Skipweasel
Pay no attention to that man behind the curtain.

Mary Fisher wrote:
"Guy King" wrote in message
...
The message
from "Mary Fisher" contains these words:

But it doesn't make sense to have it controlled by the light switch,
wasting
power when you go into the bathroom during the day.
Except in the case of our downstairs loo[1] which has a PIR controlled
light so visiting kids don't get all panicky when they shut the door and
only then realise it's utterly dark inside.

Teach them how to use the switch :-)
But the question was about a BATHroom, no mention was madeof a wc.

Not that I think it's necessary to have an extractor fan in the lav, we
don't, just the wall ventilator brick. It's not a problem now and wasn't
when five offspring lived here or when we have people staying.

Its no necessary for ventilation per se, but it IS necessary in
conjunction with modern insulation and draughtproofing standards..in
essence the theory is that you build what amounts to a hermetically
sealed polystyrene box, and then punch specific holes in it to control
moisture build up.

It works, but its a far cry from open chimneys/fires and draughty doors
and windows..

Mary

"The Natural Philosopher" wrote in message
...
Mary Fisher wrote:
"Guy King" wrote in message
...
The message
from "Mary Fisher" contains these words:

But it doesn't make sense to have it controlled by the light switch,
wasting
power when you go into the bathroom during the day.
Except in the case of our downstairs loo[1] which has a PIR controlled
light so visiting kids don't get all panicky when they shut the door and
only then realise it's utterly dark inside.

Teach them how to use the switch :-)
But the question was about a BATHroom, no mention was madeof a wc.

Not that I think it's necessary to have an extractor fan in the lav, we
don't, just the wall ventilator brick. It's not a problem now and wasn't
when five offspring lived here or when we have people staying.

Its no necessary for ventilation per se, but it IS necessary in
conjunction with modern insulation and draughtproofing standards..in
essence the theory is that you build what amounts to a hermetically sealed
polystyrene box, and then punch specific holes in it to control moisture
build up.

It works, but its a far cry from open chimneys/fires and draughty doors
and windows..

We don't have those either. Ours is an efficient house. And a warm one.

Mary

On Sat, 22 Apr 2006 21:48:18 +0100 someone who may be The Natural
Philosopher wrote this:-

Its no necessary for ventilation per se, but it IS necessary in
conjunction with modern insulation and draughtproofing standards..in
essence the theory is that you build what amounts to a hermetically
sealed polystyrene box, and then punch specific holes in it to control
moisture build up.

Moisture build up can be controlled with a suitable window. No need
to burn electricity and more reliable.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On Sat, 22 Apr 2006 21:48:18 +0100 someone who may be The Natural
Philosopher wrote this:-

Its no necessary for ventilation per se, but it IS necessary in
conjunction with modern insulation and draughtproofing standards..in
essence the theory is that you build what amounts to a hermetically
sealed polystyrene box, and then punch specific holes in it to control
moisture build up.

Moisture build up can be controlled with a suitable window. No need
to burn electricity and more reliable.


Well sure, it can, but windows let cold air (and thieves) in as well as
hot sticky air out.

The purpose of the extractor fan is to provide a secure way to exhaust
saturated air, and replace it with warm drier air from the rest of the
building..thats the theory anyway.

"David Hansen" wrote in message
...
On Sat, 22 Apr 2006 21:48:18 +0100 someone who may be The Natural
Philosopher wrote this:-

Its no necessary for ventilation per se, but it IS necessary in
conjunction with modern insulation and draughtproofing standards..in
essence the theory is that you build what amounts to a hermetically
sealed polystyrene box, and then punch specific holes in it to control
moisture build up.

Moisture build up can be controlled with a suitable window. No need
to burn electricity and more reliable.

Ah but David if you open a window you let in fresh air, which can sometimes
even be COLD!!!!!!!!!

Mary


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"The Natural Philosopher" wrote in message
...
David Hansen wrote:
On Sat, 22 Apr 2006 21:48:18 +0100 someone who may be The Natural
Philosopher wrote this:-

Its no necessary for ventilation per se, but it IS necessary in
conjunction with modern insulation and draughtproofing standards..in
essence the theory is that you build what amounts to a hermetically
sealed polystyrene box, and then punch specific holes in it to control
moisture build up.

Moisture build up can be controlled with a suitable window. No need
to burn electricity and more reliable.


Well sure, it can, but windows let cold air (and thieves) in as well as
hot sticky air out.

The purpose of the extractor fan is to provide a secure way to exhaust
saturated air, and replace it with warm drier air from the rest of the
building..thats the theory anyway.

A theory that only works if there is a way for air to enter the room with a
fan. You need a gap under the bathroom door to let warm drier air in.

Adam

On Sun, 23 Apr 2006 12:52:59 +0100 someone who may be "Mary Fisher"
wrote this:-

Moisture build up can be controlled with a suitable window. No need
to burn electricity and more reliable.

Ah but David if you open a window you let in fresh air, which can sometimes
even be COLD!!!!!!!!!

Suitably designed natural ventilation will provide adequate
ventilation without excessive cold draughts. The only "problem" is
that it requires more thought than an extractor fan.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

It happens that Mary Fisher formulated :

The PIR copes with that need.

As I said, the op asked about a bathrom, not a lavatory.

Mary

For a bathroom which does not include a lavatory then a humidity
controlled fan (no PIR) is fine.

--

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

"David Hansen" wrote in message
...
On Sun, 23 Apr 2006 12:52:59 +0100 someone who may be "Mary Fisher"
wrote this:-

Moisture build up can be controlled with a suitable window. No need
to burn electricity and more reliable.

Ah but David if you open a window you let in fresh air, which can
sometimes
even be COLD!!!!!!!!!

Suitably designed natural ventilation will provide adequate
ventilation without excessive cold draughts. The only "problem" is
that it requires more thought than an extractor fan.

Aye well, there's the rub!

Mary