Discharge Air Reset is a method to save energy by resetting the discharge air temperature setpoint as heating and cooling building loads change. When enabled, the controller can independently reset the Discharge Air Heating Setpoint Active and/or Discharge Air Cooling Setpoint Active based on Zone (space temperature), Outdoor Air temperature or Return Air Temperature. The new target setpoints are reported as Discharge Air Setpoint Heating Status and Discharge Air Cooling Setpoint Status.
Discharge Air Cooling Reset
The following user adjustable points are used to calculate the Discharge Air Cooling Setpoint reset.
Point Name | BAS Instance | App Location* | Default Value |
| Cooling Reset Type | MV-11111 | SETTINGS>SYSTEM | Outdoor Air |
| Cooling Reset Start Temp | AV-11150 | SETTINGS>SYSTEM | 90°F |
| Cooling Reset End Temp | AV-11151 | SETTINGS>SYSTEM | 70°F |
| Cooling Reset Amount | AV-11152 | SETTINGS>SYSTEM | 10°F |
| Discharge Air Cooling Setpoint BAS | AV-10121 | SETTINGS>REFRIGERATION | 55°F |
| Discharge Air Cooling Setpoint BAS - Active | AV-11190 | STATUS (Use Search Function) | 55°F |
| Discharge Air Cooling Setpoint Status | AV-11356 | STATUS (Use Search Function) | Result of Reset Calc. |
*The Symbio App only changes default values, if a BAS is writing to these points, the BAS will have control.
Using Discharge Air Cooling Reset Values above, the active Discharge Air Cooling Setpoint BAS (55°F) will be reset 10°F over the range of outdoor air temperature of 90°F (Cooling Reset Start Temperature) to 70°F (Cooling Reset End Temperature). When outdoor air temperature is greater than 90°F, no reset is applied. When outdoor air temperature is 80°F, Discharge Air Cooling Setpoint – Active will be reset 5°F. As a result, discharge air temperature will be controlled to Discharge Air Cooling Setpoint Status of 60°F. When outdoor air temperature is 69°F, discharge air temperature will be controlled to Discharge Air Cooling Setpoint Status of 65°F.
Discharge Air Heating Reset
The following user adjustable points are used to calculate the Discharge Air Heating Setpoint reset.
Point Name | BAS Instance | App Location* | Default Value |
| Heating Reset Type | MV-11136 | SETTINGS>SYSTEM | Outdoor Air |
| Heating Reset Start Temp | AV-11241 | SETTINGS>SYSTEM | 30°F |
| Heating Reset End Temp | AV-11242 | SETTINGS>SYSTEM | 50°F |
| Heating Reset Amount | AV-11343 | SETTINGS>SYSTEM | 10°F |
| Discharge Air Heating Setpoint BAS | AV-11191 | SETTINGS>HEATING | 100°F |
| Discharge Air Heating Setpoint BAS - Active | AV-11191 | STATUS (Use Search Function) | 100°F |
| Discharge Air Heating Setpoint Status | AV-11129 | STATUS (Use Search Function) | Result of Reset Calc. |
*The Symbio App only changes default values, if a BAS is writing to these points, the BAS will have control.
Using Discharge Air Cooling Reset Values above, the active Discharge Air Heating Setpoint BAS (100°F) will be reset 10°F over the range of outdoor air temperature of 30°F (Heating Reset Start Temperature) to 50°F (Heating Reset End Temperature). When outdoor air temperature is less than 30°F, no reset is applied. When outdoor air temperature is 40°F, Discharge Air Heating Setpoint – Active will be reset 5°F. As a result, discharge air temperature will be controlled to Discharge Air Heating Setpoint Status of 95°F. When outdoor air temperature is
55°F, discharge air temperature will be controlled to Discharge Air Heating Setpoint Status of 90°F.