On Wed, 1 Sep 2004 13:54:06 +0100, "IMM" wrote:


"Dave" wrote in message
...

I think a couple of people installed Heat Banks last year - what are your
views having run them for a while?

Can anyone explain the relative merits
of heating the heatbank directly or
indirectly?

When direct "all" the boilers heat goes into the store. When indirect you
are relying on the efficiency of the coil.

Why would I choose to make the primary
circuit pressurised or vented?

In theory pressurised has little advantages over vented when using a heat
bank, as long as the system is fitted correctly and inhibitor is used and
replaced every 3-4 years. Pressurised does away with the F&E tank, in a heat
bank this can be integrated with the store.


Also making the primary pressurised with a direct heatbank (i.e. the
bulk contents of the cylinder are pressurised) means that for Building
Regulations section G purposes it counts as a sealed storage system
and must therefore be installed by a certified installer.

Having the primary vented, whether with an integral F&E tank or not
means that this can be a DIY job, although is still subject to a
Building Notice because of part L1.

However, some boilers will not accept having an open vented primary,
so the choice then becomes making the heatbank a pressurised one
(professional installation) or having one with a coil on the input
side from the boiler (primary is pressurised) and the bulk water in
the heatbank being tertiary and open vented and separate from the
primary. This can be a DIY installation with Building Notice for
part L1.


..andy

To email, substitute .nospam with .gl