Optimal Start Example - Metasys - LIT-1201793 - Software Application - Metasys Site Management Portal - 12.0.50

Metasys Site Management Portal Help

Product
Building Automation Systems > Building Automation Systems > Metasys Site Management Portal
Document type
User Guide
Document number
LIT-1201793
Version
12.0.50
Revision date
2023-06-02

For an example of the optimal start process, assume:

  • The Zone Occ Mode Obj is scheduled to be occupied at 7:00 A.M. and unoccupied at 5:00 P.M.

  • Zone Temperature = 55˚F before the warmup period

  • Heating Setpoint (since in Heating mode) = 70˚F

  • Heating Deadpoint (since in Heating mode) = 5 minutes

  • Heating Constant (since in Heating mode) = 10 (The optimal start process has run for several days, and the Heating Constant has been adjusted to 10 based on past performance.)

  • Temperature Difference = 70˚F - 55˚F = 15˚F

Therefore:

Optimal Start Time = [(10/100) x 152] + 5

= (0.1 x 152) + 5

= (0.1 x 225) + 5

= 22.5 + 5

= 27.5

= 28 minutes

The optimal start process turns on the Zone WC Mode Obj at 6:32 A.M. (28 minutes prior to the scheduled 7:00 A.M. start time.)