Installation manual
26
EKHBH/X008BA
Indoor unit for air to water heat pump system
4PW54185-1B
Space heating priority temperature
—
Applies only to installations
with a domestic hot water tank.
—
The 'space heating priority
temperature' field settings apply to operation of the 3-way valve and
the booster heater in the domestic hot water tank.
When the space heating priority function is enabled, it is assured that
the full capacity of the heat pump is used for space heating only
when the outdoor temperature equals or drops below the specified
space heating priority temperature, i.e. low outdoor temperature. In
this case the domestic hot water will only be heated by the booster
heater.
■
[5-02] Space heating priority status: specifies whether space
heating priority is enabled (1) or disabled (0).
■
[5-03] Space heating priority temperature: outdoor
temperature below which the domestic hot water will be
heated by the booster heater only, i.e. low outdoor
temperature.
■
[5-04] Set point correction for domestic hot water
temperature: set point correction for the desired domestic hot
water temperature, to be applied at low outdoor temperature
when space heating priority is enabled. The corrected
(higher) set point will make sure that the total heat capacity of
the water in the tank remains approximately unchanged, by
compensating for the colder bottom water layer of the tank
(because the heat exchanger coil is not operational) with a
warmer top layer.
[6] DT for heat pump domestic water heating mode
Applies only to installations with a domestic hot water tank.
The 'DT (temperature difference) for heat pump domestic water
heating mode' field settings determine the temperatures at which
heating of the domestic hot water by the heat pump will be started
(i.e., the heat pump ON temperature) and stopped (i.e., the heat
pump OFF temperature).
When the domestic hot water temperature drops below the heat
pump ON temperature (
T
HP ON
), heating of the domestic hot water by
the heat pump will be started. As soon as the domestic hot water
temperature reaches the heat pump OFF temperature (
T
HP OFF
) or
the user set point temperature (
T
U
), heating of the domestic hot water
by the heat pump will be stopped (by switching the 3-way valve).
The heat pump OFF temperature, and the heat pump ON
temperature, and its relation with field settings [6-00] and [6-01] are
explained in the illustration below.
■
[6-00] Start: temperature difference determining the heat
pump ON temperature (
T
HP ON
). See illustration.
■
[6-01] Stop: temperature difference determining the heat
pump OFF temperature (
T
HP OFF
). See illustration.
If the booster heater operation is limited ([4-03]=0)
and the ambient outdoor temperature
T
A
is lower than
the field setting to which parameter [5-03] is set and
[5-02]=1, then the domestic hot water will not be
heated.
T
set
Domestic hot water set point temperature
T
U
User set point (as set on the user interface)
T
A
Ambient (outdoor) temperature
Space heating priority
WARNING
Be aware that the domestic hot water temperature will be
automatically increased with the value selected in field
setting [5-04] (if the outdoor temperature drops below field
setting [5-03]) compare to the user set point for domestic
hot water (T
U
). Refer to field setting [5-03], [7-00] and the
operation manual to select preferable set point.
If this high domestic hot water temperature can be a
potential risk for human injuries, a mixing valve (field
supply) shall be installed at the hot water outlet connection
of the domestic hot water tank. This mixing valve shall
secure that the hot water temperature at the hot water tap
never rise above a set maximum value. This maximum
allowable hot water temperature shall be selected
according to local and national regulations.
T
A
T
set
T
U
[5-03]
[5-04]
T
U
User set point temperature (as set on the user interface)
T
HP MAX
Maximum heat pump temperature at sensor in domestic hot
water tank (50°C)(depending on T
A
)
(a)
(a) 45°C = T
HP MAX
at T
A
>25°C.
50°C = T
HP MAX
at 5°C
≤
T
A
≤
25°C.
48°C = T
HP MAX
at T
A
<5°C.
T
HP OFF
Heat pump OFF temperature
T
HP ON
Heat pump ON temperature
The maximum domestic hot water temperature that can be
reached with the heat pump is 50°C. It is advised to select
T
HP OFF
not higher than 48°C in order to improve
performance of the heat pump during domestic water
heating mode.
When setting [4-03]=0 or 2 special attention to setting
[6-00] is recommended. A good balance between the
required domestic hot water temperature and heat pump
ON temperature (T
HP ON
) is a must.
T
U
> T
HP MAX
T(
°
C)
70
T
U
50
T
HP MAX
48
T
HP OFF
41
T
HP ON
[6-01]
[6-00]
T
U
< T
HP MAX
T(
°
C)
45
T
U
= T
HP OFF
50
T
HP MAX
38
T
HP ON
[6-00]
T
U
= 45
°
C
[6-01] = 2
°
C
[6-00] = 7
°
C
T
U
= 70
°
C
[6-01] = 2
°
C
[6-00] = 7
°
C
