Ways to Use Wireless to Operate
Buildings Better
CBE
Edward Arens, Cliff Federspiel,
David Auslander,Therese Peffer,
Charlie Huizenga
BWRC
Paul Wright, Jan Rabaey, +
BSAC
Richard White +
Berkeley Intel Lab
David Culler +
CENTER FOR THE BUILT ENVIRONMENT OCTOBER 2003
Building Systems and Their Monitoring Needs
Building
Lighting,
temperature,
sound, air
quality…
Electricity,
gas, water,
weather…
Energy
Occupancy,
comfort,
productivity
People
Current situation:
 Insufficient number
of environmental
sensors (1/1000sf)
 Ineffective placement
of sensors (limited by
wires)
 Monthly lump-sum
electricity/gas bills
 Occupants have little
information, insight, or
influence over their
building environment
CO2
sensor
Individual
recognize
sensor
Solar
radiation
sensor
Physiology
sensor
Survey of
occupant
reaction
Individual
comfort
model
Zone
temperature
sensor
Sensing and Actuation
Opportunities
Anemometer
Provide
information
Message to
occupants
Human productivity model
Suggest
action
Shading
Window
Human
schedule
Occupancy
model
Door
sensor
Building
thermal
model
Sound
sensor
Adjust
position
Total power consumption
model
HVAC
system
model
Lighting
model
Decisions
Plug load
model
Control
devices
Start
on/off
Setpoint
reset
Blinds
AC
Vent
Refriger
Shut down
Motion
sensor
Lights
Structure
temperature
sensor
Window
status
sensor
Weather
condition
Pressure
around
building
HVAC
condition
Zone light
sensor
Plug power
measurement
Computer
Office
device
Weather
condition
Daylight
illumination
Fuel/electric
price
Perspective in a Perimeter Zone
Sensing, intelligence, actuation:
VAV actuator
Climate
sensor
Light ballast
BACnet
Occupancy
sensor
Base station
Comfort stat
 Detect ambient conditions,
solar radiation, wind pressure,
natural light, perspiration,
occupancy,…
Reflective
vane
actuator
Window
switch
Desk climate sensor
 Trade-off energy, thermal
comfort, and visual need,…
 Appropriate adjustments are
made at: vav valve, light
dimmer, reflective vanes,…
Prototype wireless
lighting control system
Motivation
• Lighting accounts for ~50% of commercial building electricity
consumption
• Switching is often inadequate and inflexible and results in
significant energy waste
• One switch may control the lights for many occupants
• Switches are often not conveniently located
• “Ownership” of switches is unclear
• Switching often does not work well with daylight patterns
Objective
Develop a lighting control system that is:
• Highly flexible
• Wireless
• Cost effective
There are many wireless systems in
development and in the marketplace.
What’s different about our approach?
• Does not require special ballasts
• Will work for new or retrofit applications
• Is easily reprogrammed by the user
• Will have a low installation cost per
switch/fixture ($20 target)
System Overview
Wireless controller
Light sensor
Desktop, mobile,
or wall mounted
switch
System components
Radio motes
Wireless switch
Ballast
Power
supply
to lamps
Wireless controller
Light sensor
Motion sensor
Control flexibility
Switches can be operated by either a local
switch or through a central control system
Lighting Groups
Perimeter Daylight Group
Lighting Groups
Emergency Group
Lighting Groups
Jethro’s Workspace
Lighting Groups
Madonna’s Workspace
Control strategies
More creative strategies are possible than with a simple
switch…
Lights on/off
Lights needed/not needed
Minimum light level
Emergency lights on
Non-critical lights off
Progress
 Prototype design
 2 prototypes built
Residential Demand Response Project
Objectives:
 To respond to dynamic electricity pricing, we need:
• A meter that records time-of-use, as well as use.
• A system that can automatically operate HVAC and other
equipment in response to price signals.
• An interface that accurately obtains the occupants’ preferences
between price and comfort.
• Information devices that help the occupant respond intelligently.
• Sensors and actuators that can be easily installed, (ie, wireless).
 To be a breakthrough, this system must be inexpensive:
• $50 for meter, $30 for thermostat, $10 for sensor nodes.
• It must also last at least 10 years without battery changes.
Demand-response system
Outdoor
Sensors
Power
Indoor
Sensors
Wattmeters,
Switches,
Action-suggesting
alerts and displays
Existing
Meter
(Links by Internet or
wireless services to:)
Electrical Utility
Grid Operator
Weather Service…
(two alternatives)
Sun control blinds,
Lighting dimmers
Appliances
Refrigerator
Panel
Price schedules in,
Electric usage out
DSL, Cable, Cell-phone
text messaging, or WAN
radio system
User
Interface
Home
Server
Base
Station
(Wi-Fi or
TinyOS)
Heating System
Air Conditioner
Hot Water Heater
Smart Ventilator
Pool Pump
Demonstration Sept. 30
Attendees:
List of demos:
California Energy Comm.
DR System
Commissioner Rosenfeld
and staff
PIER staff
TAC members
CIEE
Framework
Physical model
User interface
Energy Scavenging
Light and vibration
Power on/off motes
Device prototyping
Thermostat
Price-signalling mote
Wattmeters and wireless relays
(By Richard White’s group at BSAC)
appliance
“zip” cord
120 Hz
output signal
Iout
Iin
60 Hz
AC current
MEMS cantilever with
piezoelectric film
DR System simulation and control
DR system simulated in Java code, including:
House thermal behavior.
DR control algorithms.
Wireless network
communications.
Will control the model
house via the wireless
motes.
Smart Thermostat Control
Levels
Realtime pricing
from Utility via
meter
Goal Seeking
Supervisory
Control
MED $$
Operator
HIGH $$$
• Wireless motes
• Scavenged power
• Tiny OS
Thermal comfort
vs. price
Coordination
Energy cost vs.thermal comfort and power need
 Typical energy saving setback Temperature setpoints
 Demand Response Temperature Setpoints (based on price)
 Temperature Setpoints based on adaptive model
 Preheat or precool based on advance notice of price increase
 Expert system optimize cooling or heating (temp sensors, weather forecast)
 Manual override
 Shut off
Heat or cool
Direct Control
Computer
Mote interface
(radio to hub)
Power
consumption vs.
price
Use economizer
fan or ac
What, how, when
Interface
 Operator presets typical setback Temperature setpoints
 Operator presets Demand Response temperature setpoints
(amount of temperature discomfort acceptable based on price).
 Operator maintains manual override.
On/off
On/off
On/off
high/med/low
Heater
control
(wired)
AC control
(wired)
Fan/economizer
control (wired)
 Auto control of water heater, refrigerator, pool equipment depending on price
 Send notice to motes on stove, washer, dryer, dishwasher (current price and
upcoming price)
Power to which
appliance
On/off
On/off
On/off
Appliance power sensors
LOW $
Weather forecast
(WWW)
Appliance power sensors
External
Communication
•Wireless power sensor
•Wireless relay at outlet
Smart advice
text
Traffic light on
appliance
LR
Temp
mote
BR
Temp
mote
Ext
Temp
mote
Sensor on
window or
blind
Wireless
relay
Power
sensor
Physical Target
Living
Room
Bed
room
Window/blind
Pool
equipment
Wireless
relay
Power
sensor
Water
heater
Wireless
relay
Temp mote
in Ref
Power
sensor
Operator actuated
Sensor/
Actuator
Operator actuated
• Wireless motes/tiny OS
• Scavenged power
Power
sensor
Refrigerator
Stove, Washer,
Dryer, Dishwasher
Blow dryer…
Thermostat simulation and prototyping
Working,interactive
thermostat simulated
on PC screen
Thermostat and
signalling motes
fabricated using
rapid prototyping
Energy usage screen
Obtaining user preferences
We are examining various
versions of interface—the
challenge is to balance
energy cost and comfort.