Daikin ERLA03DAV3, Installer'S Reference Manual, Page: 27 / 192

5 | Application guidelines
Installer reference guide
27
ERLA EHFZ03S18DJ3V
Daikin Altherma 3 R F
4P596821-1A – 2020.05
Determining the desired temperature for the DHW tank
Formula Example
V
1
=V
2
+V
2
×(T
2
−40)/(40−T
1
) If:
▪ V
2
=180 l
▪ T
2
=54°C
▪ T
1
=15°C
Then V
1
=280 l
V
1
DHW consumption (equivalent hot water volume at 40°C)
V
2
Required DHW tank volume if only heated once
T
2
DHW tank temperature
T
1
Cold water temperature
DHW tank volume
Integrated DHW tank volume: 180 l (=V
2
)
Energy saving tips
▪ If the DHW consumption differs from day to day, you can program a weekly
schedule with different desired DHW tank temperatures for each day.
▪ The lower the desired DHW tank temperature, the more cost effective. By
selecting a larger DHW tank, you can lower the desired DHW tank temperature.
▪ The heat pump itself can produce domestic hot water of maximum 55°C (50°C if
outdoor temperature is low). The electrical resistance integrated in the
heat pump can increase this temperature. However, this consumes more energy.
We recommend to set the desired DHW tank temperature below 55°C to avoid
using the backup heater.
▪ The higher the outdoor temperature, the better the performance of the
heat pump.
- If energy prices are the same during the day and the night, we recommend to
heat up the DHW tank during the day.
- If energy prices are lower during the night, we recommend to heat up the DHW
tank during the night.
▪ When the heat pump produces domestic hot water, it cannot heat up a space. In
case you need domestic hot water and space heating at the same, we
recommend to produce the domestic hot water during the night when there is
lower space heating demand.
5.3.3 Setup and configuration – DHW tank
▪ For large DHW consumptions, you can heat up the DHW tank several times
during the day.
▪ To heat up the DHW tank to the desired DHW tank temperature, you can use the
following energy sources:
- Thermodynamic cycle of the heat pump
- Electrical backup heater
▪ For more information about optimizing the energy consumption for producing
domestic hot water, see
"9 Configuration" [
4
96].