Setting Up An Indirect Auxiliary Heat Source For Domestic Hot Water And Space Heating - Daikin ERLA14D V3 Series Installer's Reference Manual

6 | Application guidelines

6.3.2 Setting up an indirect auxiliary heat source for domestic hot water and space heating

Installer reference guide
52
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.
Setpoint of the auxiliary gas boiler
To prevent freeze-up of the water piping, the auxiliary gas boiler must have a fixed
setpoint ≥55°C, or a weather-dependent setpoint ≥T
T (°C)
min
60
50
40
30
20
10
0
–30 –25 –20
T Outdoor temperature
a
T Minimum weather-dependent setpoint for auxiliary gas boiler
min
The auxiliary boiler (field supply) is connected to the storage tank and controlled by
the ON/OFF signal on the indoor unit. It can do the domestic hot water heating
and, if allowed by the user, space heating via tank heating support. Whether heat
pump or auxiliary boiler operates, depends on outdoor and storage tank
temperatures.
Setup
1 Integrate the auxiliary boiler as follows:
A Main leaving water temperature zone
B One single room
a Dedicated Human Comfort Interface (BRC1HHDA used as room thermostat)
b Auxiliary boiler (field supply)
min
–15 –10 –5
B
A
c
d
e
d
.
0 5
T (°C)
a
a
b
ERLA11~16D + EBSH/X(B)11+16P30+50D
Daikin Altherma 3 R ECH₂O
4P663482-1C – 2023.05