SDB DemandControlled Ventilation Preliminary Experiments Jay Taneja Software

SDB Demand-Controlled Ventilation: Preliminary Experiments Jay Taneja Software Defined Buildings Kickoff January 11 th, 2013

SDB • • Motivation SDBs can improve comfort Indoor environmental quality is multifaceted Buildings are often overventilated Demand-controlled ventilation (DCV) • DCV benefits from BOSS Architecture – Incorporates non-BMS sensors and data – Transactions ensure safe system state – Communication throughout buildings

SDB DCV: Standards and Sensors • ASHRAE 62. 1 and CA Title 24 • CO 2 sensors • Works best in enclosed spaces • Target max of 800 ppm CO 2

SDB Baseline Ventilation

SDB Extreme Efficiency Description • Preliminary control effort to limit ventilation as much as possible • Combines an occupancy model, outside air damper control sequence, and significant reductions in default airflow levels

SDB Extreme Efficiency Ventilation

SDB DCV Description • Incorporate Google Calendar data • Proportional control (airflow reflects CO 2) • Prior to meetings: Increase airflow • During meetings: Modulate minimum to reflect CO 2 concentration • Not during meetings: Only respond if CO 2 approaches 800 ppm threshold

SDB Demand-Controlled Ventilation

SDB Ventilation Strategy Results Avg. Airflow Avg. Ventilation Power Time > 800 ppm Baseline 222. 2 cfm 0. 1765 k. W 6 h 3 m (3. 6%) Extreme Efficiency 79. 8 cfm 0. 0616 k. W 10 h 57 m (6. 5%) DCV 40. 2 cfm 0. 0272 k. W 17 m (0. 2%) • Caveats – Not all weeks created equal – Could increase airflow to reduce violations DCV offers a combination of energy savings and increased occupant comfort at minimal cost.

SDB Next Steps • Expansion in SDH – 7/12 rooms with calendar data have sensors – DCF in cleanroom using motion sensors • Grid potential as a supply-following load – Minimal ability to shed (positive slack) – Substantial ability to sink (negative slack) – Incorporate MPC for balancing objectives • Integrate with BAS – write once, run anywhere

SDB Questions? Jay Taneja <taneja@cs. berkeley. edu>