Bath/Shower Extraction with no External Vent?

[Winch]

I did a brief search and couldn’t find a similar situation but that may have been me not using the correct search terms as this isn’t my field.

So in short we are trying to complete a new build 3 storey house for Building Regs Sign Off. The top floor has a bathroom and a Shower Cubicle in one of the bedrooms both of which require extraction. Fans have already been fitted in the ceilings in appropriate locations by the previous builder who has now been kicked off site for being unreliable among other things.

The site on which the house is built is such that the third storey is almost 4 storeys above ground level and surrounded by steeply sloping ground making ladder/cherry picker access either impossible or highly dangerous. All scaffolding has long since left the site. This means accessing the outside of the building will be almost impossible/prohibitively expensive to fit an external vent.

So my question is this is there some kind of a device we could fit inside the loft space which would dehumidify the extracted air from the shower and bathroom so that dry air can be vented into the loft space? If so what is this called?

I have found duct moisture traps during a Google search but based on the limited descriptions and my limited knowledge I assume that these are merely to extract any water which condenses in a duct on the way to being extracted outside?

One other fact which may be pertinent to this there is also a rain water harvesting system in the house and the “brown water” header tank is in the loft space nearby so could be used to receive water from any extract system assuming this wouldn’t contravene the Building Regs of course.

 

[bernardgreen]

It is possible to fit an external vent to a wall where there is no access to the outside face of the wall.

Basically :-

Core drill the hole from the inside.

Drop a rope through the hole down to ground level.

Assemble the vent with a length of duct long enough to pass through the wall with enough spare to connect the internal ducting to it.

Thread the rope through the duct and tie to a piece of wood to stop it going back through the vent, tie a length of string to the rope so that once the vent and duct are in place and secured the rope can be pulled out

The tricky bit is gettting the duct horizontal to get it through the hole. A thin arm through the hole with a stick to guide the vent and duct does work. Beware the stick falling to the ground and hitting someone, tether it with some string

 

[bernardgreen]

Some more information here

http://community.screwfix.com/threads/extractor-fan-vent-covers-at-high-level.132533/

 

[SFK]

Bernard, love your method and I am kicking myself that I did not think of doing that. One for me to remember for the future.

Which,
My reading of your questions is that your extractor fans are already in the bathroom ceiling and sticking into the loft. (Please do not vent directly into the loft, it is only asking for future trouble with damp).

In your loft, can I suggest you route tubing from the extractor fan to your roof soffit (the bit between the Tiles and the external Wall) where you put a vent? There should be a slight downward angle to this tube so that if any steam condensates inside the tube it can then run down the tube and out of the house at the soffit vent.

This kit (not a recommendation, simply the first I saw when I did a search for "extractor rectangular soffit vent") seems to do what I was suggesting: http://www.i-sells.co.uk/soffit-venting-kit-tight-100mm?gclid=CMvGm8WPztECFYaVGwodt9gMHg
I would use this kit slightly differently where I would connect the flexible tube directly to the fan, and then use one of the three Vents at the Soffit depending on what type of soffit you have.

sfk

 

[endecotp]

If there is any gable wall accessible, you can get vents that can be fitted through a wall from the inside:

//www.diynot.com/diy/threads/shower-bathroom-extractor-vent.471305/#post-3777261

You might be able to do the same through a soffit.