Fitting inline extractor fan into loft space

[NBee]

Hi all. I'm fitting a bathroom extractor fan, as see here: http://www.amazon.co.uk/gp/product/B005KQ2UL6?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00

I fear I may have been premature, as I'm unsure I can now extract the air from the eaves as I'd planned; I didn't realise the eaves were so restricted. Accessing the eaves from inside the loft, there's only a small gap between the joist and the roof tiles, around 60mm.

I can get my hand through to the gap below, and I reckon there's enough room to manouvre the ducting onto the grill (once the grill has been fitted from the outside through the soffit). But is it ok to squash the ducting into whatever shape necessary to fit through the gap?

I'll try and add a couple of photos to better demonstrate what I'm talking about! Thanks, in the meantime.

 

[NBee]

Here's a view of the space available:

 

[NBee]

And a pic looking down into the space above the soffit. A bit full of rubbish but should be room for the outlet grill to push through.

 

[r1flyguy]

Have you considered the box style ducting just for that section?

http://www.screwfix.com/c/heating-plumbing/ducting/cat840506

You can buy the adopters to fit either end

 

[NBee]

Oh nice, that might be just the thing. Also will be easier to fit a solid plastic component onto the grill, seeing as I'm going to be doing it blindly, feeling around amongst the cobwebs.

I assume the change in ducting shape/size won't impact the fan performance?

 

[r1flyguy]

I wouldn't have thought so NBee. It's smoother internally if nothing else.

I have this ducting for directing the hot air from my tumble dryer to he external vent, and have had no issues.

I personally can't see it causing any issue but await to be otherwise informed.

Nonetheless hope is does the job for you.

 

[NBee]

Well after all this, it turns out I can't actually fit the standard extractor vent - my soffit simply isn't wide enough.

It's about 100mm wide. The vent itself has a 100mm circular opening, then the outer part where you secure the fixings makes it around 130mm. Sigh. So...

1) Does anybody know of any smaller sized vents that I can fit into the soffit? Or is 100mm the smallest?

2) How much of a bodge job would it be to simply squeeze the flexible ducting out of a hole, make sure it's a secure fit, and tie some mesh over the end of it? I mean, it would do the job, right?!

 

[NBee]

No replies, but no worries - I wasn't going to be beaten. I took a hacksaw to the external vent casing and chopped the sides off, cut an opening into the soffit, and hey presto it fits like a glove. Now my fan is all ducted in and ready to go.

Now, over to the electrics forum to see how I wire it in...!