Background

Source: Cisco

• Typical Building Lifecycle (Cisco, 2005)– More than 75% of Expenses occur in the Operating Period

– But most of the time and focus are in the development period

• Building energy systems do not operate as developed– 15~30% of energy is wasted (Katipamula and Brambley, 2005)

– Up to 70% of the service costs can be saved (Li and Braun, 2007)

• Smart Bldg solutions: Automated monitoring, diagnostics and optimization– Wireless sensor network based monitoring is one of the enablers

Example Technology: Cascade VAV Optimal Control Strategy Using WSN and AFDD

Duct work

FanTerminal boxes: 1, 2,…i,…n

VFD Controller

Static Pressure Controller

-+

DP/Load analyzer

Damper position of the critical zone

Wireless Sensor

Network

100%rDP ,s rP sP DPs

-+

Automated Fault Diag.

• Optimal VAV control strategy is to maintain the damper associated with the critical zone fully open– Primary control loop: Reset the static pressure set point (SPSP)

– Secondary control loop: Modulate fan speed to meet the SPSP

– WSN: obtain all damper positions -- AFDD: Diagnosis on system functionality

– DP/Load analyzer: Identify the critical zone

Preliminary Results

The optimal VAV control strategy (damper position rest) using WSN can save more energy than the other two existing methods while ensuring comfort

Comfort can not be met from 8~10 due to deficiency of supply air if either airflow rate reset or OA temperature reset method is used

Testing Bed Development

CEEN WSN Lab

AE Intelligent Bldg. Syst. Lab

Establishment of the UNL Smart Building Center

NCERS

Yr1:$62,946Yr2:$65,254

Sensus M.I.

Yr1: $56,640Yr2: $60,000

Indus Sponsors

Target: $128,517

$upport Technol Transfer

$upport

Underground: $10k