On Sat, 15 Jan 2011 11:27:33 +0000 (GMT)
JTM wrote:

In article ,
TheOldFellow wrote:
I'm considering fitting one of these. Perhaps this one:
http://www.cvcdirect.co.uk/Whole%20H...t-akorhe..html

Is there anyone with any experience of them? Are they
any good? Or do you really need to go the whole hog and
spend thousands.
Looking at the prices; £400+ for the unit then all the
ducting and face plates and power, it starts adding up.

Do you need the heat exchanger?

Yes, I live in Cumbria. What comes thought the trickle vents is an
icy blast - in July.

As it's a DIY jobby for me I thought I might make the ducts and
fittings. I can't see why 25mm celotex and 6mm ply can't be used to
make square-section insulated ducting, it's just a matter of the right
cross sectional area and tight joints.

The power is an issue though. Especially if it doesn't deliver the
stated thermal transfer efficiency, or it falls off rapidly as the
filters clog.

R.