User Manual

9
3.2 The principal functions
3.2.1 Heating and cooling curve module
Advantages:
– High level of room comfort.
– Fully automatic changeover between heating and cooling.
– Permits/disables general heating or cooling operations dependent on outside
temperature.
– Scheduled shift of flow temperature setpoints
(e.g. weekend operation).
The innovative heating and cooling curve module controls flow temperature for one
heating circuit. The heating and cooling curves are based on mean outside air
temperature over the past 24 hours (sliding time window). The heating and cooling
curve is derived on the mean outside air temperature and the required flow
temperature setpoint to ensure the desired level of room comfort.
The nominal heating and cooling curves apply to the nominal room temperature
setpoints for heating and cooling. The heating and cooling curves are adjusted
accordingly when the desired room temperature setpoints do not equal the nominal
room temperature setpoints.
The time scheduled shift of the heating and cooling curves is used when it is known
in advance that heat gains will vary significantly in the rooms of a zone on specific
days. This shift is typically used to compensate for a lack of heat gain caused by
non-occupancy over the weekends or during the holidays. The heating and cooling
curves are adjusted upward for these periods.
The heating and cooling limits are established based on the average outside air
temperature, which in turn enables heating and cooling modes. The module can be
optionally configured for Summer/Winter compensation to further improve comfort
conditions.
Figure 2-3
Heating and cooling curves as well as heating and cooling limits.
Note: The cooling limit can be lower than the heating limit (as is the case here)
Ccrv Cooling curve HLm Heating limit
CLm Cooling limit MovAvTOa Moving average outside temperature
Hcrv Heating curve ZTFl Zone flow temperature