Condensation on a bathroom extractor fan

[Darkwood]

Sorry for the delay, the house is under modernisation. the bathroom door has not been hung yet and the bathroom ufh is operational but not used on the programmer yet or regular. There is a towel rail on the central heating (wet) but only comes on for a short time if at all in the evening. The windows are often opened during the day whilst work is going on. The floor is tiled to ceiling on two sides of the shower cubicle (glass screen on other two sides 2m heigh) and to a metre down one side,the dimension of bathroom are 3.6x2x2.65 heigh. The fan is an icon 30 and will perform @ 32l/sec or 118cubic metres /hr.

The fan comes on with lights and turns off on a timer. It clears the steam no problem so I would say it is adequate

as for the heater could I not just plug it into the socket in the shower cubicle? Lol

Steam is visual saturation .... humidity can be 100% without you seeing it, heavily tiled bathrooms exposed to open windows and lengthy showers will leave a cold surface for condensation to appear on, again its down to modern pampered living and and regardless of fan if they are excessive showerers then no domestic fan will cope...

 

[GB.Kayak]

Sorry for the delay, the house is under modernisation. the bathroom door has not been hung yet and the bathroom ufh is operational but not used on the programmer yet or regular. There is a towel rail on the central heating (wet) but only comes on for a short time if at all in the evening. The windows are often opened during the day whilst work is going on. The floor is tiled to ceiling on two sides of the shower cubicle (glass screen on other two sides 2m heigh) and to a metre down one side,the dimension of bathroom are 3.6x2x2.65 heigh. The fan is an icon 30 and will perform @ 32l/sec or 118cubic metres /hr.

The fan comes on with lights and turns off on a timer. It clears the steam no problem so I would say it is adequate

as for the heater could I not just plug it into the socket in the shower cubicle? Lol

So having given the background information about the installation, when does the condensation form on the fan grill?

 

[telectrix]

fit a heating element to the fan grille but don't feed it from the shower.

 

[Tidy Max]

I wouldn't of bridged the cavity between the insulation and the wall with the expanding foam. The cold will be travelling straight from the outside wall through the foam and onto your fan, does it feel cold to the touch?

 

[JulianC]

My advice - wait till the door is hung, the UFH is in regular use and the windows aren't left open all day while work is undertaken. No point trying to tackle a problem which may evaporate (oh! the hilarity) once normal occupant behaviour is resumed.

 

[Engineer54]

I wouldn't of bridged the cavity between the insulation and the wall with the expanding foam. The cold will be travelling straight from the outside wall through the foam and onto your fan, does it feel cold to the touch?

Hogwash!! So what about the cavity wall insulation balls, that gets pumped into cavities or the expanding foam type insulation sprayed into cavities??

Insulation material does not conduct either heat or cold, that's why it's called ''insulation''

 

[GB.Kayak]

Hogwash!! So what about the cavity wall insulation balls, that gets pumped into cavities or the expanding foam type insulation sprayed into cavities??

Insulation material does not conduct either heat or cold, that's why it's called ''insulation''

Dear Eng54, you have such contempt for those who are ill qualified to speak or practise in the realms of electrical installation; for which I have some sympathy, to do with competency level and the potential risk that they present to others. Yet you come out with this which shows a classic over simplification at best, lack of understanding on your own part at worst, of the laws of physics regarding conduction. Laws with which you are, I assume, well acquainted as an Electrical Engineer. Is there such a thing as a perfect insulator? In the world of heat energy there are things that conduct heat quickly and with little resistance and those that do not conduct heat energy as efficiently, just as in the world of electrical energy. Insulators are categorised in the latter camp but not being 'perfect', they still conduct! In addition, heat and cold are not 'conducted' they are a measure of the 'activity' level of a substance due to its level of 'stored' energy; potential difference if you like. Basic physics wouldn't you say?

 

[Engineer54]

Just how much indepth explanation would you think is plausible here?? Over simplification it maybe but is totally relevant to the situation. The expanding foam insulation in this case isn't going to make the internal wall as cold (or anywhere near) as the external wall....

So what are you saying, that insulation material doesn't insulate between hot and cold and visa versa??

 

[telectrix]

30-15. eng54 to serve!

 

[HandySparks]

Insulation material does not conduct either heat or cold, that's why it's called ''insulation''

And a conductor has no resistance, otherwise it would be called a resistor. Ha ha ha. :rofl:

 

[Guest125]

popcorn!

 

[GB.Kayak]

Just how much indepth explanation would you think is plausible here?? Over simplification it maybe but is totally relevant to the situation. The expanding foam insulation in this case isn't going to make the internal wall as cold (or anywhere near) as the external wall....

So what are you saying, that insulation material doesn't insulate between hot and cold and visa versa??

Insulation reduces the rate of heat loss ... it doesn't prevent it! At what point does over simplification = dumbing down? At what point does someone regurgitate ... I heard the engineer say ... at which point professionalism may be called into question. The correct description does not have to be complicated. I am saying what I have said which is basic physics and anything that says that heat and cold can be conducted or insulated is in my opinion misleading and can lead to unnecessary confusion in the future.

I do however recognise that in order to explain complicated concepts simplification is often necessary. We have not all studied degree level thermodynamics. Most of which I have long since forgotten!

 

[Anthony S]

There as been cases where cold spots have been found to appear on the inner leaf after the full injection of insulation in hard to fill cavities. So is that some sort of cold bridging ? who knows and who really cares.

 

[Engineer54]

God, we could nit pick to the enth degree on every single Thread/Post on that basis....


OK just for you,let's just say that insulation between two surfaces reduces the transfer between hot and cold to a point it is Extremely unlikely that one side of the insulation will have any great effect on the other side... Is that better for you??

 

[GB.Kayak]

There as been cases where cold spots have been found to appear on the inner leaf after the full injection of insulation in hard to fill cavities. So is that some sort of cold bridging ? who knows and who really cares.

God, we could nit pick to the enth degree on every single Thread/Post on that basis....

OK just for you,let's just say that insulation between two surfaces reduces the transfer between hot and cold to a point it is Extremely unlikely that one side of the insulation will have any great effect on the other side... Is that better for you??

Are these rhetorical questions ... to which answers are unwanted or unwelcome ... or would a sensible answer be welcomed?

 

[telectrix]

if air was a better insulator than fibreglass/kingspan/etc., then they wouldn't stuff the crap in studded walls and ceiling voids.

 

[Anthony S]

if air was a better insulator than fibreglass/kingspan/etc., then they wouldn't stuff the crap in studded walls and ceiling voids.

Behave yourself, they do it just for a p*ss take lol

 

[telectrix]

hah. went to do a quote last year. 320 LED downlights to 2nd fix in ceilings with 4" celotex wedged in. no cut-outs, just cables coming through 1" ( rough) holes in board. quoted double what i thought, just to make sure i didn't get the job.

 

[tex431]

No cavity wall- Victorian house.

 

[HandySparks]

if air was a better insulator than fibreglass/kingspan/etc., then they wouldn't stuff the crap in studded walls and ceiling voids.

Air is a better insulator than glass, which is why most of the volume of fibreglass insulation is air. The point being that the fibres prevent convection (and to some extent, radiation), which is largely how an unfilled cavity wall transmits thermal energy.

 

[GB.Kayak]

if air was a better insulator than fibreglass/kingspan/etc., then they wouldn't stuff the crap in studded walls and ceiling voids.

Oh dear, oh dear, oh dear ... the thermal conductivity, insulation value, of:


- Dry air @ 275 deg K ~ 2 deg C is 0.024 W / m K, @ 300 deg K ~ 27 deg C is 0.026
Dry Air Properties


- Polyisocyanurate foam, 'Kingspan' is 0.023 W / m K or 0.022 W / m K or 0.019 to 0.023 W / m K
Polyisocyanurate - Wikipedia, the free encyclopedia or
Celotex GA4000 Insulation Board for Floors, Walls and Roofs or
Kingspan Insulation - Kooltherm Rigid Insulation for Roof Wall & Floor Applications | Thermal Insulation - Kingspan UK


- Glassfibre 1.2 to 1.35 W / m K
Properties: E-Glass Fibre


What the manufacturers' brochures do not tell you ... the thermal properties of polyisocyanurate foam are dependent upon the gas used to 'blow' the foam. This gas can 'leak' and reduce the thermal properties of your insulation, it becomes a ~ 17 % better conductor in the first 6 months; a less effective insulator than dry air. In some other manufacturers' foams, I do not know about all, less than environmentally friendly gasses have been used as the insulating medium. The products of combustion of the foam are amongst the primary killers in house fires.


Glass fibre relies on its air content to do its insulating job ...


Air ... its problem is if heated it changes density and being a gas will rise being replaced by cooler, denser air. Its problem is heat movement by convection not conduction ... though its insulating properties are negatively affected by its moisture content.


As with all things, a little knowledge is a dangerous thing ... and you can prove anything with statistics, badly designed experiments, poorly chosen comparators or blatant withholding of the truth!


Furthermore, don't believe anything a marketing specialist tells you about the product that they are selling until you have used it and proven its capability and your need for it before buying!

 

[Leesparkykent]

Oh dear, oh dear, oh dear ... the thermal conductivity, insulation value, of:


- Dry air @ 275 deg K ~ 2 deg C is 0.024 W / m K, @ 300 deg K ~ 27 deg C is 0.026
Dry Air Properties


- Polyisocyanurate foam, 'Kingspan' is 0.023 W / m K or 0.022 W / m K or 0.019 to 0.023 W / m K
Polyisocyanurate - Wikipedia, the free encyclopedia or
Celotex GA4000 Insulation Board for Floors, Walls and Roofs or
Kingspan Insulation - Kooltherm Rigid Insulation for Roof Wall & Floor Applications | Thermal Insulation - Kingspan UK


- Glassfibre 1.2 to 1.35 W / m K
Properties: E-Glass Fibre


What the manufacturers' brochures do not tell you ... the thermal properties of polyisocyanurate foam are dependent upon the gas used to 'blow' the foam. This gas can 'leak' and reduce the thermal properties of your insulation, it becomes a ~ 17 % better conductor in the first 6 months; a less effective insulator than dry air. In some other manufacturers' foams, I do not know about all, less than environmentally friendly gasses have been used as the insulating medium. The products of combustion of the foam are amongst the primary killers in house fires.


Glass fibre relies on its air content to do its insulating job ...


Air ... its problem is if heated it changes density and being a gas will rise being replaced by cooler, denser air. Its problem is heat movement by convection not conduction ... though its insulating properties are negatively affected by its moisture content.


As with all things, a little knowledge is a dangerous thing ... and you can prove anything with statistics, badly designed experiments, poorly chosen comparators or blatant withholding of the truth!


Furthermore, don't believe anything a marketing specialist tells you about the product that they are selling until you have used it and proven its capability and your need for it before buying!

F**k about,I read the first three lines and got bored haha

 

[Tidy Max]

Hogwash!! So what about the cavity wall insulation balls, that gets pumped into cavities or the expanding foam type insulation sprayed into cavities??

Insulation material does not conduct either heat or cold, that's why it's called ''insulation''

What is the purpose of leaving the required breathable gap either side of foam insulation when plasterboarding a ceiling? i thought it was to stop the cold transferring though the insulation and causing condensation/damp onto the plasterboard?

That was my logic behind the suggestion anyway.

 

[ruston]

F**k about,I read the first three lines and got bored haha

Don't mess about there Lee, just say what you feel.

 

[Geordie Spark]

Don't mess about there Lee, just say what you feel.

I think we should make Lee an Honorary Geordie for that

 

[ruston]

I think we should make Lee an Honorary Geordie for that

Aye, as blunt as a ceramic filleting knife.

 

[Leesparkykent]

I think we should make Lee an Honorary Geordie for that

I'll drop kent off the end of my forum name and no one will be any the wiser ;-)

 

[Engineer54]

As with all things, a little knowledge is a dangerous thing ... and you can prove anything with statistics, badly designed experiments, poorly chosen comparators or blatant withholding of the truth!

So is too much knowledge by the sound of it!!

 

[mache]

Oh dear, oh dear, oh dear ... the thermal conductivity, insulation value, of:


- Dry air @ 275 deg K ~ 2 deg C is 0.024 W / m K, @ 300 deg K ~ 27 deg C is 0.026
Dry Air Properties


- Polyisocyanurate foam, 'Kingspan' is 0.023 W / m K or 0.022 W / m K or 0.019 to 0.023 W / m K
Polyisocyanurate - Wikipedia, the free encyclopedia or
Celotex GA4000 Insulation Board for Floors, Walls and Roofs or
Kingspan Insulation - Kooltherm Rigid Insulation for Roof Wall & Floor Applications | Thermal Insulation - Kingspan UK


- Glassfibre 1.2 to 1.35 W / m K
Properties: E-Glass Fibre


What the manufacturers' brochures do not tell you ... the thermal properties of polyisocyanurate foam are dependent upon the gas used to 'blow' the foam. This gas can 'leak' and reduce the thermal properties of your insulation, it becomes a ~ 17 % better conductor in the first 6 months; a less effective insulator than dry air. In some other manufacturers' foams, I do not know about all, less than environmentally friendly gasses have been used as the insulating medium. The products of combustion of the foam are amongst the primary killers in house fires.


Glass fibre relies on its air content to do its insulating job ...


Air ... its problem is if heated it changes density and being a gas will rise being replaced by cooler, denser air. Its problem is heat movement by convection not conduction ... though its insulating properties are negatively affected by its moisture content.


As with all things, a little knowledge is a dangerous thing ... and you can prove anything with statistics, badly designed experiments, poorly chosen comparators or blatant withholding of the truth!


Furthermore, don't believe anything a marketing specialist tells you about the product that they are selling until you have used it and proven its capability and your need for it before buying!

So basically in all that you are agreeing that in a domestic situation, where air won't be dry and where it won't be still you are better off with an expanded foam insulation or glass fibre because it is those parts that prevent the air from moving around, hence providing the insulation factor and is why we wear clothes because they prevent direct enviromental air from cooling down our body because the clothes slow down the air movement changes. Our do you walk around in winter in just your budgie smugglers in the hope that theroetical properties of air at ideal conditions will stop you getting pneumonia....

 

[GB.Kayak]

So basically in all that you are agreeing that in a domestic situation, where air won't be dry and where it won't be still you are better off with an expanded foam insulation or glass fibre because it is those parts that prevent the air from moving around, hence providing the insulation factor and is why we wear clothes because they prevent direct enviromental air from cooling down our body because the clothes slow down the air movement changes. Our do you walk around in winter in just your budgie smugglers in the hope that theroetical properties of air at ideal conditions will stop you getting pneumonia....

I wouldn't wear glass fibre, I find that it itches too much ... I find that polyisocyanurate foam doesn't drape well and shrinks leaving gaps! ;-))

 

[ruston]

I wouldn't wear glass fibre, I find that it itches too much ... I find that polyisocyanurate foam doesn't drape well and shrinks leaving gaps! ;-))

The space foil can be manipulated easily and is quite trendy.:beatnik2: