Controlling Sutardja Dai Hall

Andrew KrioukovStephen Dawson-Haggerty, Jay Taneja

David Culler

Buildings

40% of US electricity42% of greenhouse gas footprint

• Want:– Energy Efficiency– Flexible Load

Building Power Consumption

11%

1MW883 kW

Sutardja Dai Hall

3 years old

7 floors, 140k sq. feet

Collaboratories, offices, classrooms, auditorium & nanofab

Siemens Controls, WattStopper> 6000 sensors & actuators

Building Control NetworkSensors,Actuators Controllers

WattStopperServer

Modem

Internet

sMAP/HTTP

Readings& Actuation

BACnet/IPGateway

Modem

Siemens P2over RS-485

SiemensServer

Cooling Tower

Chiller

Economizer Air Handler

Hot Water

VAV VAV VAV

Problems

1. Oblivious control loops– Increasing thermostat on warm day wastes energy– Conflicting controls

2. Oversizing – Excess ventilation– Oversized chiller

Inefficient, Inflexible Control

Why?Modular Building ControllerMotorola 68302 16.67 MHz Processor3MB RAMRS-485 @ 300 - 115.2K bps60 day battery backup

• Hardware:– Resource limited– Reliability is the goal– Supports independent operation

• Generic control logic:Oversizing ensures comfortable operation in most buildings with less effort

• Historic:Replacing pneumatic/analog controls

Goal

Globally-aware control with the same reliability.

• What is the architecture?– How to ensure: robustness, security and safety?

• What is the control policy?

Building Control Architecture

Internet

Weather,Energy Prices

Low-levelControl

Sensors & Actuators

High-levelControl

Set points,PID parameters

Valve pos,Damper pos,

Fan speed

Building-wide optimization

PID Loops

How to do “atomic” building configuration changes?Security model?Enforcing safety constraints.

Policy Components

• Supply air temp• Airflow• Room set points• Cold water pumps• Chiller• Hot water pumps

Variable Air Volume (VAV) Box

• Ventilation• Maintain temperature

100%

0%

Cold AirflowHeating Valve

Setpoint Too HotToo Cold

Min airflow

VAV Control100% Cooling

100% Heating

Dead band

Conflicting VAVsMax Cooling• S1-1 – Boiler room• S4-4 – Floor 4 open office• S5-8 - Floor 5 office• S5-10 - Floor 5 open office • S7-13 - Floor 7 open office• S7-10 - Floor 7 open office• S7-1 - Floor 7 open office

Max heating• S1-9 - Mechanical Room• S4-20 - Floor 4 open office• S5-9 - Floor 5 hallway • S5-21 - Floor 5 open office• S5-4 - Floor 5 open office• S7-9 - Floor 7 open office• S7-3 - Floor 7 open office

Ventilation

• TITLE 24: – 15 CFM per person of fresh air– 900 – 1100 PPM CO2

• VAVs have static minimum airflow base on:– Maximum occupancy– Minimum fresh air intake

Fresh Air Intake

Questions?