MULTIPLE INSTALLATIONS
26
PRESSURE REDUCING VALVE COMMISSIONING PROCEDURE
The pressure reducing valves must be set and commissioned for each water heater so the water heaters will
turn on and off in sequence when the flow rate increases or decreases to a particular rate. This procedure
can be conducted with either cold water or solar heated water, however the temperature of the solar heated
water must not exceed 58°C.
The water heater installation should be sized and the number of water heaters selected to cater for the cold
water temperature in winter and assuming a period of no solar gain without any solar heated water available.
The climate chart is based on a flow rate from a shower outlet not exceeding 9 litres per minute and a
tempered water temperature of 42°C.
Climate Chart
Number of Shower Outlets – 27L Models
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
number of water heaters
warm / tropical climate
(20°C inlet temperature)
1
1
1
2
2
2
3
3
3
3
4
4
4
5
5
5
6
6
6
6
number of water heaters
moderate climate
(15°C inlet temperature)
1
1
2
2
2
3
3
3
4
4
4
5
5
6
6
6
-
-
-
-
number of water heaters
cool climate
(10°C inlet temperature)
1
1
2
2
3
3
3
4
4
5
5
6
6
6
-
-
-
-
-
-
Note:
If there are other hot water outlets which may operate simultaneously with the shower outlets, then the
operation and flow rates of these outlets need to be considered and an allowance made when selecting the
number of water heaters for the application.
TYPICAL INSTALLATION
– MULTIPLE GAS BOOSTER WATER HEATERS
