September 23, 2009 1

Presented by:Presented by: Geoffrey C. Bell, PEGeoffrey C. Bell, PEChris Abbamonto, CEM, LEED APChris Abbamonto, CEM, LEED AP

Credit to:Credit to: Rebecca Lally, UCI EH&SRebecca Lally, UCI EH&SFred Bockmiller, PE, UCI FacilitiesFred Bockmiller, PE, UCI Facilities

Centralized Demand Control Ventilation Centralized Demand Control Ventilation (CDCV) (CDCV)

for Laboratory Facilitiesfor Laboratory Facilities

Environmental Energy Technologies DivisionEnvironmental Energy Technologies Division

Does CDCV Allow Ventilation Rate Reductions & Does CDCV Allow Ventilation Rate Reductions & Save Energy Without Compromising Safety? Save Energy Without Compromising Safety?

September 23, 2009 2

CDCV Overview:CDCV Overview:Optimizing lab air change rate…Optimizing lab air change rate…

Often set at a “constant rate” 24/7Often set at a “constant rate” 24/7 Recommended range 4 to 12 air changes Recommended range 4 to 12 air changes

per hourper hour Usually excessive during low-level Usually excessive during low-level

process activity or non-occupancyprocess activity or non-occupancy Explore possibility of “set back” based on Explore possibility of “set back” based on

lab pollutant concentration…lab pollutant concentration…

September 23, 2009 3

CDCV - A Retrofit OpportunityCDCV - A Retrofit Opportunity

Risk Assessment of LabsRisk Assessment of LabsScrutinize air change ratesScrutinize air change ratesConsider Control BandingConsider Control Banding

Baseline Lab Facility OperationBaseline Lab Facility OperationPerform Lab Airflow SurveyPerform Lab Airflow SurveyTest Lab VAV system periodicallyTest Lab VAV system periodically

Labs21 Partnership ProgramLabs21 Partnership ProgramBenefits are numerous…Benefits are numerous…

September 23, 2009 4

CDCV Overview: CDCV Overview:

September 23, 2009 5

CDCV Air-Sampling Network: CDCV Air-Sampling Network: Distributed, Multi-PointDistributed, Multi-Point

Air Data Air Data RouterRouter

Room Room SensorSensor

September 23, 2009 6

Is CDCV effective in reducing the contaminant

concentration from a spill in a lab?

CDCV and Safety: CDCV and Safety:

September 23, 2009 7

Spill Test MethodologySpill Test Methodology 500 ml of acetone500 ml of acetone Baseline measurement (6 ACH) without Baseline measurement (6 ACH) without

CDCV and then (4 ACH) with CDCV CDCV and then (4 ACH) with CDCV activated activated

Photoionization detector - 10.6 eV lampPhotoionization detector - 10.6 eV lampMiniRae 2000 instrumentMiniRae 2000 instrumentCalibrated by factoryCalibrated by factory

CDCV minimum response level: CDCV minimum response level: 0.5 ppm0.5 ppm

CDCV polling interval time: CDCV polling interval time: 14-17 minutes (without CO sensing)14-17 minutes (without CO sensing)

September 23, 2009 8

Spill Locations Spill Locations

Farthest point from the hood

In front of the hood

Benchtop

September 23, 2009 9

CDCV System Polling Time 5 Minutes After Spill

020406080

100120140160180200220240260280300320340360

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75minutes after spill

pp

m o

f A

ceto

ne

Baseline 6 ACH- w/outCDCV

4 ACH (w/CDCV)

Air Contaminant Monitoring Results:Air Contaminant Monitoring Results: Spill Farthest Point from Hood - Sash ClosedSpill Farthest Point from Hood - Sash Closed

4 ACH

12 ACH

CDCV on @ 5 min.

September 23, 2009 10

CDCV System Polling Time 17 Minutes After Spill

020406080

100120140160180200220240260280300320340360

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75

minutes after spill

pp

m o

f A

ceto

ne

Baseline 6 ACH- w/outCDCV

4 ACH (w CDCV)

4 ACH

12 ACH

CDCV on @ 17 min.

Air Contaminant Monitoring Results:Air Contaminant Monitoring Results: Spill Farthest Point from Hood - Sash Closed Spill Farthest Point from Hood - Sash Closed

September 23, 2009 11

Air Contaminant Monitoring Results:Air Contaminant Monitoring Results:Combined ResultsCombined Results

Overlay of 6 ACH w/o CDCV and w/ CDCV 5/16 Minute Polling

020406080

100120140160180200220240260280300320340360

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75minutes after spill

pp

m o

f A

ceto

ne Baseline 6 ACH (no CDCV)

4 ACH w/ CDCV 16min.

4 ACH w/ CDCV 5 min.

September 23, 2009 12

Spill Results: Spill Results: SummarySummary

Event Pre-spill

ACH

Post-spill

ACH

Minutes post- spill ventilation increased

Peak

Conc.

(ppm)*

<4 ppm* Clearance

Time

(min.)

Baseline

Spill

w/o CDCV

6 6 n/a 339 73

Spill 1 w/CDCV 4 12 5 219 70

Spill 2

w/CDCV 4 12 17 227 76

* MiniRae 2000

September 23, 2009 13

Safety Conclusions:Safety Conclusions:CDCVCDCV

Responsive to spillsResponsive to spillsEffective for sensing acetone levelsEffective for sensing acetone levelsLowers peak concentration in open areasLowers peak concentration in open areas

Polling time could result in delay in Polling time could result in delay in detecting spilldetecting spill

No significant difference in clearance No significant difference in clearance timetime

September 23, 2009 14

Lessons Learned…Lessons Learned…

Set polling interval frequency based on risk assessmentSet polling interval frequency based on risk assessment

Current sensor suite does not detect all chemicals Current sensor suite does not detect all chemicals

Sensor selection should be based on risk assessment Sensor selection should be based on risk assessment

System failure must “fail safe” to 6 ACHSystem failure must “fail safe” to 6 ACH

September 23, 2009 15

Important Safety ConsiderationsImportant Safety Considerations CDCV is an Energy Management System

– Not meant to be a life safety system– Provides historical IAQ info

Can minimize impact of fugitive emissions

Consider emergency override exhaust ventilation “red” button

Provide visual display or notification inside and outside the lab

September 23, 2009 16

Is CDCV effective in reducing energy usage in

a lab?

CDCV and Energy: CDCV and Energy:

September 23, 2009 17

CDCV and Energy SavingsCDCV and Energy Savings

Goal: Reduce ACH rate by lowering CFM Goal: Reduce ACH rate by lowering CFM delivered to laboratory spaces with CDCVdelivered to laboratory spaces with CDCV

Installation Discoveries/Retro-Installation Discoveries/Retro-CommissioningCommissioningBad control system cardsBad control system cardsBad air-valve solenoidBad air-valve solenoidPoor thermostat locationPoor thermostat locationLow duct static pressureLow duct static pressureSupply air temperature reset 65 deg FSupply air temperature reset 65 deg FCFM adjustment made for actual room sizeCFM adjustment made for actual room size

September 23, 2009 18

Energy Savings Found During Installation Energy Savings Found During Installation

Poor Thermostat LocationsPoor Register Locations

September 23, 2009 19

Croul Hall CFM / Air Change RateCroul Hall CFM / Air Change Rate

Pre CDCV

After CDCV

~9,500 CFM Reduction!

CDCV System PaybackCDCV System PaybackSample Data Annualized

 Average CFM kW Load

Fan Energy kWh

Chiller Energy kWh

Preheat MMBtu

Reheat MMBtu

Base 31,454 24 213,084 202,900 330 2,957

CDCV 21,739 15 130,716 140,216 228 2,043

Savings 9,715 9 82,368 62,684 103 914

Reduction 31% 39% $ 6,178 $ 4,701 $ 1,080 $ 9,634

Total Annualized Savings $ 21,593

1. Used Lawrence Berkeley Fume hood cost calculator to estimate heat load and chiller energy based on UCI-specific central plant efficiencies

2. Chiller data was 0.75 kW/ton and heating 74% plant efficiency

3. Climate data was an average of El Toro and Long Beach data.

4. Electrical Cost = $0.075 per kWh, Heating cost = $7.80 per MMBtu/plant efficiency

September 23, 2009 21

CDCV System PaybackCDCV System Payback

System Installation Cost with 5 year System Installation Cost with 5 year sensor change-out: $125,000sensor change-out: $125,000Extra cost for deferred maintenanceExtra cost for deferred maintenanceRetro-commissioning required additional time Retro-commissioning required additional time

and cost but netted additional savings.and cost but netted additional savings.

Observed ~9,500 CFM reductionObserved ~9,500 CFM reduction Anticipated payback: 2-5 yearsAnticipated payback: 2-5 years Future sensor calibration and Future sensor calibration and

maintenance costs unknown…maintenance costs unknown…

September 23, 2009 22

Lessons LearnedLessons Learned

Arrange EMS display with real-time ACHArrange EMS display with real-time ACH Require direct user-notification of failureRequire direct user-notification of failure Training necessary for uses and Training necessary for uses and

maintenance staffmaintenance staff Establish service contract for sensor Establish service contract for sensor

change-outchange-out Additional CDCV system benefitsAdditional CDCV system benefits

Lab temperatureLab temperature IAQ sensed data IAQ sensed data CCx data and LEEDCCx data and LEED

September 23, 2009 23

Future ProjectsFuture Projects

Additional testing scenarios Additional testing scenarios 4 ACH normal operation4 ACH normal operation2 ACH unoccupied2 ACH unoccupied

CDCV Currently being installed in our CDCV Currently being installed in our newest “Smart Lab” building at UC Irvinenewest “Smart Lab” building at UC Irvine

September 23, 2009 24

Working with LBNLWorking with LBNL

Integrated teamIntegrated team Objective professional feedbackObjective professional feedback Positive experiencePositive experience

Technical Bulletin in review and available Technical Bulletin in review and available in about a monthin about a month

September 23, 2009 25

For More Information For More Information

Geoffrey C. Bell, P.E.Geoffrey C. Bell, P.E.

510.486.4626510.486.4626

gcbell@lbl.govgcbell@lbl.gov

http://ateam.lbl.govhttp://ateam.lbl.gov

Questions?Questions?

Facilities and Environmental Energy TechnologiesFacilities and Environmental Energy Technologies

sustainability.uci.edusustainability.uci.edu

Chris AbbamontoChris Abbamonto

949.285.3172949.285.3172

cabbamon@uci.educabbamon@uci.edu