Hi


I like the look of this one. Well done to IMM. Assorted quotes.


.. and probably quite quickly since the first heat exchanger will
have
very cold mains water and have quite a transfer rate. A typical
domestic system will have 60-100 litres in the primary circuit so
there is a reasonable amount of stored energy but at the likely
temperature, less than a thermal store. Interesting nonetheless.

But that isnt a problem in itself. When you're filling a bath it makes
little difference if the first half of the fill is faster or hotter
than the second, its the total fill that matters. Extracting the CH
heat will improve fill speed relative to simple boiler output alone.


Most people,bath in winter
rather than summer, so perfect.

I find this an odd comment though


In summer, taking just 10C of heat from the rads is going to reduce
summer HW heating costs a little: the heating temp rise will be about
20-65 = 45C instead of 10-65 = 55C. Thats in the region of 20%
reduction, and thus also 20% more heat / flow at the tap than you
would get by just running the cold mains through the boiler.


Now onto the conservatory bit:

It could be honed to be more efficient, here and there. One way is to
have
the cold water mains that supplies the DHW laid under a concrete
floor of a
southish facing conservatory in 22mm pipe. This also acts as a
pre-heat. So,
1st stage pre-heat, the conservatory. 2nd stage the heat stored in
the
system, the third the boiler. It is extracting heat from around the
building
to do something useful, rather than waste space with stored water
cylinders.

While this could be done, it is a particularly inefficient way of
doing solar heating, and would have no real hope of paying for its
installation cost.

The heat gained from the conservatory is free via solar gain.

not at all, it would be especially expensive. Piping and plumbing is
not free.


There are other ways to improve the heat delivery to the bath and cut
energy use as well. Another heat exchanger under the bath, operating
between the cold bath tap /shower and the bath waste pipe will recycle
much of the heat that goes down the drain during showers, and will
thus enable a HW system of limited capacity to deliver much more
performance, since the HW is mixing with a warmer cold supply. And it
looks like thats just whats needed on this system. And from what I've
seen the payback looks good for these.


Regards, NT