Daikin Altherma EHVH/X11+16S18CB - Setting up the Domestic Hot Water Tank; System Layout - Integrated DHW Tank; Selecting the Volume and Desired Temperature for the DHW Tank

5 Application guidelines
Installer reference guide
17
ERHQ+ERLQ011~016 + EHVH/X11+16S18+26CB
Daikin Altherma – Low temperature split
4P384975-1C – 2018.02
L
N
H Com
A
K2AK1A
X2M
B
TI
K2AK1A
Indoor/Auto/Boiler
1 2 3 4 X Y
Indoor
B
TI
Boiler thermostat input
A Auxiliary contact (normal closed)
H Heating demand room thermostat (optional)
K1A Auxiliary relay for activation of indoor unit (field supply)
K2A Auxiliary relay for activation of boiler (field supply)
Indoor Indoor unit
Auto Automatic
Boiler Boiler
NOTICE
▪ Make sure the auxiliary contact has enough differential
or time delay to prevent frequent changeover between
indoor unit and auxiliary boiler.
▪ If the auxiliary contact is an outdoor temperature
thermostat, install the thermostat in the shadow so that
it is NOT influenced or turned ON/OFF by direct
sunlight.
▪ Frequent changeover may cause corrosion of the
auxiliary boiler. Contact the manufacturer of the
auxiliary boiler for more information.
5.4 Setting up the domestic hot water
tank
5.4.1 System layout – Integrated DHW tank
Only for EHVH/X.
FHL1
FHL2
FHL3
M
UI
a b c d hh if
e
g
a Outdoor unit
b Indoor unit
c Heat exchanger
d Backup heater
e Pump
f Motorised 3‑way valve
g DHW tank
h Shut-off valve
i Collector (field supply)
FHL1...3 Underfloor heating
UI User interface
5.4.2 Selecting the volume and desired
temperature for the DHW tank
People experience water as hot when its temperature is 40°C.
Therefore, the DHW consumption is always expressed as equivalent
hot water volume at 40°C. However, you can set the DHW tank
temperature at a higher temperature (example: 53°C), which is then
mixed with cold water (example: 15°C).
Selecting the volume and desired temperature for the DHW tank
consists of:
1 Determining the DHW consumption (equivalent hot water
volume at 40°C).
2 Determining the volume and desired temperature for the DHW
tank.
Determining the DHW consumption
Answer the following questions and calculate the DHW consumption
(equivalent hot water volume at 40°C) using typical water volumes:
Question Typical water volume
How many showers are needed
per day?
1shower = 10min×10l/min =
100l
How many baths are needed per
day?
1bath = 150l
How much water is needed at the
kitchen sink per day?
1sink = 2min×5l/min = 10l
Are there any other domestic hot
water needs?
—
Example: If the DHW consumption of a family (4 persons) per day
is as follows:
▪ 3 showers
▪ 1 bath
▪ 3 sink volumes
Then the DHW consumption = (3×100l)+(1×150l)+(3×10l)=480l
Determining the volume and 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
2
=V
1
×(40−T
1
)/(T
2
−T
1
) If:
▪ V
1
=480l
▪ T
2
=54°C
▪ T
1
=15°C
Then V
2
=307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
Possible DHW tank volumes
Type Possible volumes
Integrated DHW tank ▪ 180l
▪ 260l
Standalone DHW tank ▪ 150l
▪ 200l
▪ 300l
▪ 500l
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.