Condensation on a bathroom extractor fan

[Octopus]

M ... 'warmth' does not condense, moisture vapour condenses!

Er no. Just being picky are you??

So are you going to answer the points about what is really going on??

 

[Anthony S]

Hi got a customer who has a icon 45 bathroom extractor fan, fitted by myself and it develops water droplets on the front grill and drips on the floor. It is flush mounted in the wall through a 40mm polystyrene backed plaster board. I have put some expanding foam between the wall and the back of the plasterboard. Due to the nature of the wall I put a duct through the wall 150mm long, sloping out with a back draft flapper on the wall no water runs in the duct, it only forms on front grill. Any suggestion? Probably going to swop fan to a different brand. Never had this problem with this particular fan before

No different to when you see water droplets on window/door trickle vents, its condensation.

 

[GB.Kayak]

Er no. Just being picky are you??

So are you going to answer the points about what is really going on??

Yes ... but pedantic is my middle name! As to what is really going on, I couldn't possibly say as I am not the OP!

 

[Anthony S]

Its about a good balance between: heating, ventilation, insulation

 

[LankyWill]

It's probably due to the coned design of the cover. Why not swap it for a vortice filo 4 or even a vortice quadro micro. The quadro is very powerful and will work on a 4" duct.

 

[Octopus]

Hi got a customer who has a icon 45 bathroom extractor fan, fitted by myself and it develops water droplets on the front grill and drips on the floor. It is flush mounted in the wall through a 40mm polystyrene backed plaster board. I have put some expanding foam between the wall and the back of the plasterboard. Due to the nature of the wall I put a duct through the wall 150mm long, sloping out with a back draft flapper on the wall no water runs in the duct, it only forms on front grill. Any suggestion? Probably going to swop fan to a different brand. Never had this problem with this particular fan before

When? and under what circumstances?

 

[specs]

Funny enough the door has not been fitted yet and I checked the flap opens

you mean there is no door and yet still droplets on grill.

 

[Octopus]

you mean there is no door and yet still droplets on grill.

So hot house, cold air outside is behind grill of fan and the client is surprised that there is condensation??

I do wish the OP would come back and add information!

 

[Darkwood]

I've had this before ... turned out the owner was using the shower for 40mins ...4 " fans are only really designed to cope with a certain amount of moisture in the air to maintain condensation build up... as has already been said - modern living, excessive temperatures and showers that take longer than having a bath.

 

[tex431]

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

 

[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: