Danfoss DHP-H User Manual page 13

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 axis 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 (-0)
no operation
Figure 7: starting and stopping heat pump operation based on integral values .
The integral value calculation stops during hot water production and during heat stop.
Integral value calculation resumes two minutes after completed hot water production to give
the heating system time to stabilise the temperature.
INTEGRAL A1
INTEGRAL A2
Heating deficit
Aux heater
start (-0)
auxiliary
Compressor
Heat surplus
Compressor
stop (≥0)
Compressor
start (-0)
Aux heater stop
Aux heater
(latest at -0)
start (-0)
no operation
VUBMA102
INTEGRAL A1
INTEGRAL A2
Time
auxiliary heater
Compressor
Heat pump operation
Danfoss – 1