I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?


Many thanks for you help

i'm not sure about your duct sizing, but i'm curious as to why you need to
move so much air AND where is the replacement air coming from?

s


wrote in message
...
I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?


Many thanks for you help

On 23 Jan, 14:04, "Steve Barker"
wrote:
i'm not sure about your duct sizing, but i'm curious as to why you need to
move so much air AND where is the replacement air coming from?

s

wrote in message

...
I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). *System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?

Many thanks for you help

I have used a fan size calculator for a bathroom with a power shower
and this the figure it came out with for a room of this size. I am
currently moving 90 cubic meteres an hour and it is not sufficient -
mould, condensation, rust etc . The replacement air is coming from the
hall outside the bathroom.

wrote in message
...
On 23 Jan, 14:04, "Steve Barker"
wrote:
i'm not sure about your duct sizing, but i'm curious as to why you need to
move so much air AND where is the replacement air coming from?

s

wrote in message

...
I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?

Many thanks for you help

I have used a fan size calculator for a bathroom with a power shower
and this the figure it came out with for a room of this size. I am
currently moving 90 cubic meteres an hour and it is not sufficient -
mould, condensation, rust etc . The replacement air is coming from the
hall outside the bathroom.


*If you are ducting the fan outside then you need to have your replacement
air come from outside as well. Otherwise you just create a vacuum and the
exhaust fan does almost nothing. If your fan is ducted to exhaust in the
house then the hall replacement air should suffice. Try opening a window in
another part of the house whenever the exhaust fan is on and see if that
makes a difference. 90 cubic meters is a lot of air. Off hand I would say
that you don't have sufficient replacement air to actually have any
significant flow.

As far as duct size you should go with the fan manufacturers
recommendations.

On Fri, 23 Jan 2009 06:00:43 -0800 (PST),
wrote:

I need to extract 247 cubic metres per hour from my bathroom...
I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,

You do know the problems of all flexible ducts? At best the
ridges greatly reduce actural air flow at worse they collect
condensation causing other problems.

In article , wrote:
On 23 Jan, 14:04, "Steve Barker"
wrote:
[top-posting corrected]
wrote in message

...
I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you

i'm not sure about your duct sizing, but i'm curious as to why you need to
move so much air AND where is the replacement air coming from?

What do you mean, "so much air"?? 247 cubic meters per hour is 145 cubic feet
per minute, which isn't really all that much. Rule of thumb for venting a
bathroom is 1.07 cfm per square foot of floor space, so that corresponds to an
area of about 136 sq ft. What's the big deal?

On Fri, 23 Jan 2009 09:37:45 -0500, John Grabowski wrote:

wrote in message
...
On 23 Jan, 14:04, "Steve Barker"
wrote:
i'm not sure about your duct sizing, but i'm curious as to why you need to
move so much air AND where is the replacement air coming from?

s

wrote in message

...
I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm ¡V 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are ¡§system 125¡¨ (150mm x 70mm) or ¡§System
204¡¨ (204mm x 60mm). System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?

Many thanks for you help

I have used a fan size calculator for a bathroom with a power shower
and this the figure it came out with for a room of this size. I am
currently moving 90 cubic meteres an hour and it is not sufficient -
mould, condensation, rust etc . The replacement air is coming from the
hall outside the bathroom.


*If you are ducting the fan outside then you need to have your replacement
air come from outside as well. Otherwise you just create a vacuum and the
exhaust fan does almost nothing. If your fan is ducted to exhaust in the
house then the hall replacement air should suffice. Try opening a window in
another part of the house whenever the exhaust fan is on and see if that
makes a difference. 90 cubic meters is a lot of air. Off hand I would say
that you don't have sufficient replacement air to actually have any
significant flow.

I have NEVER seen a fart fan NOT ducted outside and they never had outside
airflow supply. To do so eliminates heated or air conditioned air in that
room. Instead, the return air should have a filtered fresh air supply.

As far as duct size you should go with the fan manufacturers
recommendations.

On Jan 23, 8:00*am, wrote:
I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). *System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?

Many thanks for you help

Is heat forced air, try having fan run 24-7 for now. Spray mold with
laundry bleach. If forced air maybe you need better supply and
returns. There are alot of other possibilities like overhumidifying
your home with a humidifier that you have not gone into. In winter
ducting outside is a waste unless its new tight construction and you
are to humid. There is alot more to the overall picture nobody knows
about, is this a Steam Room.

On 23 Jan, 15:35, ransley wrote:
On Jan 23, 8:00*am, wrote:





I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). *System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?

Many thanks for you help

Is heat forced air, try having fan run 24-7 for now. Spray mold with
laundry bleach. If forced air maybe you need better supply and
returns. There are alot of other possibilities like overhumidifying
your home with a humidifier that you have not gone into. In winter
ducting outside is a waste unless its new tight construction and you
are to humid. There is alot more to the overall picture nobody knows
about, is this a Steam Room.- Hide quoted text -

- Show quoted text -

No this is not a steam room it is a normal bathroom. Only partly tiled
aound the bath. A power shower is over the bath ie not an enclosed
unit. The fan is threre to simply extract steam and condensation when
the shower is on, in order to prevent the build up of condesation. The
room is heated with a radiator. the room is not airtight and air is
simply replenished from gaps around the door leading into an interior
hall.

On Jan 23, 12:00*pm, wrote:
On 23 Jan, 15:35, ransley wrote:





On Jan 23, 8:00*am, wrote:

I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). *System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?

Many thanks for you help

Is heat forced air, try having fan run 24-7 for now. Spray mold with
laundry bleach. If forced air maybe you need better supply and
returns. There are alot of other possibilities like overhumidifying
your home with a humidifier that you have not gone into. In winter
ducting outside is a waste unless its new tight construction and you
are to humid. There is alot more to the overall picture nobody knows
about, is this a Steam Room.- Hide quoted text -

- Show quoted text -

No this is not a steam room it is a normal bathroom. Only partly tiled
aound the bath. A power shower is over the bath ie not an enclosed
unit. The fan is threre to simply extract steam and condensation when
the shower is on, in order to prevent the build up of condesation. The
room is heated with a radiator. the room is not airtight and air is
simply replenished from gaps around the door leading into an interior
hall.- Hide quoted text -

- Show quoted text -

So how is house humidity, ductwork, you are missing the picture and
dont get it.

On Fri, 23 Jan 2009 06:00:43 -0800 (PST),
wrote:

I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?


Many thanks for you help


Metal or PVC ductwork will move more air than flexible hose due to air
turbulance. I use 4" metal ductwork for bath and clothes dryer
exhaust.

wrote:

No this is not a steam room it is a normal bathroom. Only partly tiled
aound the bath. A power shower is over the bath ie not an enclosed
unit. The fan is threre to simply extract steam and condensation when
the shower is on, in order to prevent the build up of condesation. The
room is heated with a radiator. the room is not airtight and air is
simply replenished from gaps around the door leading into an interior
hall.

Pick out the fan and see what the manufacturer recommends. Most
likely the 4" duct will be adequate.

R

John Grabowski wrote:

... 90 cubic meters is a lot of air.

But 90 m^3/h is only 53 cfm.

A better solution, IMO:

http://www.sunfrost.com/efficient_shower.html

Nick