Danfoss DHP-H Installation And Service Instructions Manual page 32

HEATSTOP
The HEATSTOP function automatically stops all production of radiator heat when the outdoor temperature is equal to, or higher than, the
value entered for heat stop.
When the heat stop function is activated, the circulation pump will be turned off - except when hot water is being produced. The circula-
tion pump will be "exercised" for 1 minute per day. The factory set value for activating heat stop is an outdoor temperature of 17°C. If the
heat stop function is active, the outdoor temperature must drop 3°C when setting, before the heat stop stops.
MIN and MAX
The MIN and MAX values are the lowest, respectively highest set point values that are allowed for the supply temperature.
Adjusting the minimum and maximum supply temperatures is particularly important if your home has under floor heating.
If your house has under floor heating and parquet floors, the supply temperature must not exceed 45°C. Otherwise there is a risk that the
parquet floors might be damaged If you have under floor heating and stone tiles, the MIN value should be 22-25°C, even in summer when
no heating is required. 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 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
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
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.
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 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 fac-
tory settings for the integral values that the heat pump has. When the integral value has reached the set value for INTEGRAL A1, the com-
pressor 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.
Integral Heat surplus
(Heat demand)
Compressor start
(-60)
Auxiliary heater start
(-660)
No operation
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.
More specific conditions for starting and stopping the heat pump are described in the "Operating conditions" chapter.
2
INTEGRAL A1
INTEGRAL A2
Heating deficit
Auxiliary
heater
Compressor
Figure 57: Starting and stopping heat pump operation based on integral values .
Heat surplus
Compressor stop
(≥0)
Compressor start
(-60)
Auxiliary heater stop Auxiliary heater start
(latest at -60) (-660)
No operation
VMBMA102
INTEGRAL A1
INTEGRAL A2
Time
Auxiliary
heater
Compressor
Heat pump
operation