eta 13180 LP-D, Installation Manual

Page: 31 / 88

Buffer storage tank Connection between multiple buffer storage tanks
31
8.3 Connection between multiple
buffer storage tanks
Parallel connection
When there are several buffers, parallel connection
(top with top and bottom with bottom) is usually the
better solution. With a parallel connection, the entire
buffer volume is available to installed heat exchangers
such as solar heat exchangers or internal water heat
exchangers and suspended hot water tanks.
If two buffer storage tanks of different dimensions are
connected in parallel, then the flow must be connected
to the higher buffer or the lower buffer must be raised
so that the upper connection can be horizontal.
1 Flow
2 Solar heating system flow
3 Return
4 Solar heating system return
5 Return
Serial connection
A serial connection between two buffers has no
advantages over a parallel connection; but it does dis-
advantages. For example, a suspended hot water tank
can get no heat from the second buffer or an internal
heat exchanger cannot heat to both buffers. For this
reason, with serial buffers one should connect the
solar heating system using either heat exchangers in
both buffers or (preferred) with an external heat
exchanger.
1 Flow
2 Return
With rare exceptions, the use of the serial connection
(buffer 2 top and buffer 1 bottom connected) is limited
to overcoming spatial constraints of a particular instal-
lation. If passage to a door must be kept free or if there
is a long distances between buffers, only a serial
connection will be possible