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6.5 - Water loop volume
6.5.1 - Minimum water loop volume
The heat pump is used in a domestic hot water application and
must heat an intermediate loop that supplies domestic hot water
via a heat exchanger. The primary loop is charged with softened
water. Regular checks must be carried out on the water system
to detect possible scale formation. The heat pump in this type of
application must never supply domestic hot water directly.
The minimum water loop volume, in litres, is given by the following
formula:
Volume (l) = CAP (kW) x N, where CAP is the nominal heating
capacity at nominal operating conditions.
Heating or domestic hot water application
N
61AF 022-055
5,0 l
61AF 075-105
3,0 l
This volume is required to obtain temperature stability and
precision.
To achieve this volume, it may be necessary to add a storage tank
to the circuit. This tank should be equipped with baffles to allow
mixing of the fluid (water or brine). Please refer to the examples
below.
Bad
Good
Bad
Good
6.5.2 - Expansion tank volume
Units with hydraulic module do not incorporate an expansion tank.
This must be included in the water loop.
The table below gives the buffer tank volume that must be
provided, based on the water loop volume, the fluid used and its
concentration.
Expansion tank volume required
% of water loop
volume
(1)
Pure water
3,0
10 % ethylene glycol
3,0
20 % ethylene glycol
3,5
30 % ethylene glycol
3,8
40 % ethylene glycol
4,2
(1) Calculation based on a charge temperature of 10°C.
6.6 - Plate heat exchanger pressure drop
curves
For pure water at 20°C
Water flow rate, l/s
Pressure drop, kPa
0
5
10
15
20
25
30
0
1
2
3
4
5
1
2
3
4
1 61AF 022
2 61AF 030
3 61AF 035
4 61AF 045
Water flow rate, l/s
Pressure drop, kPaa
0
10
20
30
40
50
0
2
4
6
8
10
1
2
3
1 61AF 055
2 61AF 075
3 61AF 105
6 - APPLICATION DATA
Summary of Contents for AquaSnap 61AF 022
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