Danfoss DHP-AX User Manual page 14

damaged. If you have under floor heating and stone floors, MIN should not be too
low in order to achieve a comfortable floor temperature in the summer time when
heating is not required. A possible solution to obtain optimum temperatures is to
use a shunt group for under floor heating.
If your house has a basement, the MIN value should be adjusted to a suitable tem-
perature 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
and the radiator valves are trimmed correctly. As it is usually the end customers
themselves who have to carry out trimming, remember to inform them how to
carry it out correctly. Also remember that the value for HEAT STOP needs adjusting
upwards for summer heating.
3.4.6 TEMPERATURES
The heat pump can display a graph showing the history of the various sensors' tem-
peratures and you can see how they have changed over 60 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.
3.4.7 INTEGRAL
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 system uses several parameters.
A heat deficit is needed to start the heat pump, and there are two integral values,
A1 (default value = -60), which starts the compressor and A2, (default value = -600),
which starts the 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 A1+A2.
DHP-AX – 14 VUBMI102