RTF RTUG Update Aug 12, 2010 “The Turn of the Screw” Premium Ventilation Extended Monitoring Reid Hart, PE Associate Director Technical Research Group

Premium Ventilation Fan Cycling DCV Research Funded by: Bonneville Power Administration Incentive Partners: EWEB & ETO

Premium Ventilation Package Savings – Not Yet Updated DOE2 based analysis

Program-wide Savings Distribution The histogram of probability for different savings results based on the full range of baseline influences and combinations: There is a VERY WIDE spread of savings results

Significant Ventilation Improvements Fan in “auto” During January, little daytime operation CO 2 concentration almost triple desired After retrofit, highest CO 2 concentration within target limits. Single return air sensor worked for multiple rooms: –Computer lab –Billiard room

Excessive CO 2 Peaks Eliminated (peak hour/month) Premium Vent Installation

Occurrences View Movement from pre more into desired range

Manufacturing Office No significant increase in CO 2 Premium Vent Installation

Electronic Controls are as Accurate as a “Screw Turn” Very difficult to adjust accurately –Solid state controllers require a voltage generator during setup to properly adjust DCV setpoints –Matching sensor range and output to the controller is non-trivial Minimums require guesswork Need “Contractor TAB”

Thermostats Succeptable to Occupant Setings Continuous fan operation during much of post period

Daily Energy Use Patterns Took a cold spell to fix it VSD fan has lower use

Its Time for Stand-Alone DDC Its time to let the low cost, 35 year old solid-state economizer controllers go. Just too many wires up on the roof. A combined programmable thermostat with BACnet DDC controller is now here at a reasonable price from multiple manufacturers.

DCV Integrated Fan Control (DCV-IFC) Sequence Improvements –Occupancy Sensor based setpoint and ventilation –Duty cycling would circulate air at least every 30 minutes –Stand-alone demand reduction –Allow night flush cooling Advantages of DCV-IFC –Interface with any staged rooftop unit with an economizer, –With the fan off when not needed less damper leakage –Greater savings than VSD power reduction at low speed –Lower cost as no VSDs and associated wiring or motor upgrades are required. –Higher reliability, as electronic economizer (solid-state) controls are replaced with digital logic. –Ventilation monitored and controlled

PORTLAND ENERGY CONSERVATION, INC. © California Commissioning Collaborative Questions? Reid Hart x324