Setting Up An Auxiliary Heat Source For Space Heating - Daikin Altherma EHVH08SU18CB6W Installer's Reference Manual

▪ Efficiency.
▪ Depending on the demand, the indoor unit supplies different
leaving water temperature matching the design temperature of
the different heat emitters.
▪ Under floor heating has the best performance with Altherma LT.
5.3 Setting up an auxiliary heat source
for space heating
▪ Space heating can be done by:
▪ The indoor unit
▪ An auxiliary boiler (field supply) connected to the system
▪ When the room thermostat requests heating, the indoor unit or the
auxiliary boiler starts operating depending on the outdoor
temperature (status of the changeover to external heat source).
When the permission is given to the auxiliary boiler, the space
heating by the indoor unit is turned OFF.
▪ Bivalent operation is only possible for space heating, NOT for
domestic hot water production. Domestic hot water is always
produced by the DHW tank connected to the indoor unit.
INFORMATION
▪ During heating operation of the heat pump, the
heat pump operates
temperature set via the user interface. When weather-
dependent operation is active, the water temperature is
determined automatically depending on the outdoor
temperature.
▪ During heating operation of the auxiliary boiler, the
auxiliary boiler operates to achieve the desired water
temperature set via the auxiliary boiler controller.
Setup
▪ Integrate the auxiliary boiler as follows:
a b c d e g f
M
f
o n
m
a Outdoor unit
b Indoor unit
c Heat exchanger
d Backup heater
e Pump
f Shut-off valve
g Motorised 3‑way valve (delivered with DHW tank)
h Non-return valve (field supply)
i Shut-off valve (field supply)
j Collector (field supply)
k Auxiliary boiler (field supply)
l Aquastat valve (field supply)
m DHW tank
ERLQ004~008CA + EHVH04+08SU18+26CB6W
Daikin Altherma – Low temperature split
4P449978-1B – 2018.07
to achieve the desired
h j
h
i
k
l i
FHL1
FHL2
FHL3
5 Application guidelines
n Heat exchanger coil
o Booster heater
FHL1...3 Under floor heating
NOTICE
▪ Make sure the auxiliary boiler and its integration in the
system complies with applicable legislation.
▪ Daikin is NOT responsible for incorrect or unsafe
situations in the auxiliary boiler system.
▪ Make sure the return water to the heat pump does NOT exceed
55°C. To do so:
▪ Set the desired water temperature via the auxiliary boiler
controller to maximum 55°C.
▪ Install an aquastat valve in the return water flow of the
heat pump.
▪ Set the aquastat valve to close above 55°C and to open below
55°C.
▪ Install non-return valves.
▪ Make sure to only have one expansion vessel in the water circuit.
An expansion vessel is already pre-mounted in the indoor unit.
▪ Install the digital I/O PCB (option EKRP1HB).
▪ Connect X1 and X2 (changeover to external heat source) on the
digital I/O PCB to the auxiliary boiler thermostat.
▪ To setup the heat emitters, see
system" on page 12.
Configuration
Via the user interface (quick wizard):
▪ Set the use of a bivalent system as external heat source.
▪ Set the bivalent temperature and hysteresis.
NOTICE
▪ Make sure the bivalent hysteresis has enough
differential to prevent frequent changeover between
indoor unit and auxiliary boiler.
▪ Because the outdoor temperature is measured by the
outdoor unit air thermistor, install the outdoor unit 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.
Changeover to external heat source decided by an auxiliary
contact
▪ Only possible in external room thermostat control AND one
leaving water temperature zone (see
heating system" on page 12).
▪ The auxiliary contact can be:
▪ An outdoor temperature thermostat
▪ An electricity tariff contact
▪ A manually operated contact
▪ ...
▪ Setup: Connect the following field wiring:
L
H Com
Indoor/Auto/Boiler
A
K1A K2A
N
"5.2 Setting up the space heating
"5.2 Setting up the space
Indoor
B TI
X2M
1 2 3 4 X Y
K1A K2A
Installer reference guide
17