The Optimum Start/Stop Program OSTP of a control system is used to optimally control energy consumption of building zones. The OSTP aims at achieving the longest possible temperature setback on heating and temperature increase on cooling during the night, weekends, and holidays
The start-up time for heating or cooling of a building zone is calculated by the OSTP to reach the desired setpoint temperature (inside temperature of a building zone) at the beginning of occupancy.
The switch-off time for heating or cooling of the building zone is calculated by the OSTP to allow the inside temperature to be lowered (heating) or to be increased (cooling) by at most the predefined value until the end of occupancy.
If either the outside temperature assigned to the building zone or the inside temperature drops below the set limit values, frost-related zone reactions are triggered.
- Frost protection outside: Circulation pumps ON
- Frost protection inside: Heating ON at reduced stage
Depending on how long a building zone has not been used, the zone-internal setpoint at the beginning of the next occupancy is increased for heating. This temporary setpoint increase e.g. following weekends or holidays compensates for the higher heat loss a room occupant experiences due to cold radiation from the cooled-off interior building walls.
The programmed zone reactions are triggered on each status
change of the building zone such as:
- Boost heating ON
- Control operation
- Frost protection outside