Does anyone know if Optimum Start Control needs to be modelled in the Baseline case for ASHRAE 90.1-2019 and 2022 Appendix G?
Some clues:
- Optimum Start Control is found in Section 6.4.3.3.3 as one of the mandatory provisions, but not found in Appendix G.
- ASHRAE 90.1-2019 User's Manual does not mention about Optimum Start Control in Appendix G.
PNNL ASHRAE 90.1-2019 Performance Rating Method Reference Manual describes as follows, but I doubt it.
I found many parts of the Reference Manual have not been updated and are just copied and pasted from the 90.1-2010 edition. ASHRAE 90.1 underwent significant updates in its 2016 edition. Prior to this, Appendix G Baseline case frequently referenced mandatory provisions. Since the 2016 edition, Appendix G has many original Baseline case specifications, such as Envelop U-factor, Chiller COP, and LPD, which are different from Mandaroty provisions. Daylighting control is a mandatory provision but it shall not be modelled in the Appendix G Baseline case. Basically, the specifications of the Appendix G Baseline case have been downgraded from mandatory provisions. Given these circumstances, the fact that Optimum Start Control is a mandatory provision does not necessarily mean it is required for the Appendix G Baseline case.
- Table 3.1 G requires that baseline schedules capable of modeling hourly variations in occupancy, lighting power, miscellaneous equipment power, thermostat setpoints, and HVAC system operation shall be same as proposed design although there are a few exceptions. Modeling Optimum Start Control may conflict with this requirement.
