Danfoss DHP-AL User Manual page 12

value should be 22-25°C, even in summer when no heating is required. Also remember that
the value for HEATSTOP needs adjusting upwards for summer heating. This is to achieve a
comfortable floor temperature.
If your house has a basement, the MIN value should be adjusted to a suitable temperature
for the basement in summer. A condition for maintaining the heat in the basement in the
summer is that all radiators have thermostat valves that switch off the heat in the rest of the
house. It is extremely important that the heating system in the house is trimmed correctly,
see the "Trimming the heating system" section for further information. Also remember that
the value for HEATSTOP needs adjusting upwards for summer heating.
TEMPERATURES
The heat pump can display a graph showing the history of the various sensors' temperatures
and you can see how they have changed over 100 measurement points in time. The time
interval between the measurement points can be adjusted between one minute and one
hour, factory setting is one minute.
History is available for all sensors, but only the set value is shown in the display for the room
sensor. The integral value that may appear is the heating system's energy balance.
INTEGRAL
The information below tells you how your heat pump works, there are no values that you as a
customer have to set.
The heat demand in the house depends on the season and weather conditions and is not
constant. The heat demand can be expressed as temperature difference over time and can be
calculated giving an integral value as a result (heat demand). To calculate the integral value,
the control computer uses several parameters.
A heat deficit is needed to start the heat pump, and there are two integral values, A1 and A2,
which start the compressor and auxiliary heater. During heat production, the deficit reduces
and when the heat pump stops, the inertia in the system causes a surplus of heat.
The integral value is a measurement of the surface under the time axle and is expressed
in degree minutes. The figure below shows the factory settings for the integral values that
the heat pump has. When the integral value has reached the set value for INTEGRAL A1, the
compressor starts and if the integral value does not drop but continues to rise, the auxiliary
heater starts when the integral value has reached the set value for INTEGRAL A2.
Heat surplus
Integral
(Heat demand)
Compressor
start (-60)
Auxiliary heater
start (-660)
No operation
Figure 8: Starting and stopping heat pump operation based on integral values .
Danfoss – 12
INTEGRAL A1
INTEGRAL A2
Heating deficit
Auxiliary
heater
Compressor
Heat surplus
Compressor
stop (≥0)
Compressor
start (-60)
Auxiliary heater stop Auxiliary heater
(latest at -60) start (-660)
No operation
VUBMF102
INTEGRAL A1
INTEGRAL A2
Time
Auxiliary
heater
Compressor
Heat pump operation