speaker: don fedyk - nebb...speaker: don fedyk . proposing a new tracer gas for fume ... fume hood...

Speaker: Don Fedyk

Proposing a New Tracer Gas for Fume

Hood Testing

Member, NEBB Board of Directors Chairman, NEBB FHT Committee

MY DAY JOB

Manager Air Filtration Management - NY Fume Hood Testing

Cleanroom Validation

Environmental Systems Testing/Balancing

Building System Commissioning

Sound & Vibration Testing

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The awareness by World Community of the dangers of Climate Change has created a new focus for our industry. We are looking for new & innovative ideas for energy conservation as well as reducing the introduction of GREEN HOUSE GASES.

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ESTABLISHMENT OF A COMMITTEE

Development of ASHRAE RP-1573, "Determination of suitable replacement for

SF6 when used as a tracer gas in accordance with ANSI/ASHRAE Standard 110."

FHT Program

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The FHT Programs at NEBB and ASHRAE are pursuing a tracer gas

that will not cause an environmental “disaster” while allowing us to verify

the efficiency and safety of laboratory and research enclosures

What is NEBB?

Proven leader in providing technical expertise for

Research and Technological Environmental Systems.

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Providing the expertise to attain the maximum efficiency without

sacrificing safety in the Built Environment

NEBB’s Involvement

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While FUME HOOD TESTING is one area of involvement for NEBB, continued research and development for the rapidly growing healthcare

industries will require the expertise available from all our NEBB Certified Professionals (CP’s) and

Technicians (CT’s) .

Besides providing a safer environment, we are able to promote the competency of our

organization and provide a viable opportunity for NEBB firms and CP’s

1 LABORATORIES

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FUME HOODS

CLEANROOMS

4 AN ENDLESS LIST OF HAZARDOUS ENVIRONMENTS

Testing

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Each requires a different set

of rules!

Performance Evaluation

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The performance of an exposure control device is ultimately determined by its ability to control exposure to within applicable standards or other safe limits.

Exposure Control Devices

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There are numerous exposure control devices including:

• Local exhaust hoods, and other ventilated enclosures

• Glove boxes

• Biological Safety Cabinets (BSC)

• Laboratory Fume Hoods

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REALIZATION

TESTING IS FOR SAFETY

PROVING THE CONTAINMENT

ANSI/ASHRAE 110-1995

The purpose of this standard is to specify a quantitative & qualitative test method for

evaluating the containment of a laboratory fume hood.

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This method of testing applies to conventional, bypass, auxiliary air, and

VAV laboratory fume hoods.

Meeting the Need!

NEBB is stepping up to meet the needs in all AREAS.

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Continuation and enhancement of the training available not just for our CP’s and

CT’s but for the clients and future customers to gain a better understanding

of the role NEBB can play.

NEBB FHT Procedural Standard

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Establish a uniform and systematic set of criteria for the performance

testing of fume hoods.

Task Analysis

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Prior to the start of any project, whether FHT, CPT, TAB, etc. a task

analysis should be performed.

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Collection of Information

Test Requirements

Instrumentation

Submittals

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Preparation for Testing

Verify Test Procedures

Acquisition of Instrumentation

Mobilization Strategy

Task Analysis

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Discipline Specific

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Fume Hood Performance Testing

Verify System Type

Verify System Readiness

Establish Test Matrices

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FHT Velocity

Hot-wire Anemometer!

Evaluate Results

Test Setup

Evaluation

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Velocity is not an indicator of containment.

It verifies the uniformity of the intake as well as provides a

baseline for future evaluation.

Then why measure velocity?

Instrumentation

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Temperature compensation

Data logging and Averaging

Individual point readings

One-second readings

Hot-wire Anemometer

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FHT Visualization

Evaluate Results

Evaluate Results

Major Challenge

Local Challenge

FHT Tracer Gas

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FHT Tracer Gas

Test Setup

Evaluate Results

Ejector

Analyzer

Instrumentation

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Placement

Field Verification Electronic flow meter / Bubble gauge

Specifications ASHRAE 110 / NEBB FHT PS

Ejector

Instrumentation

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Analyzer

Instrument List ASHRAE 110 / NEBB FHT PS

Field Verification Instrument dependent

One-second data logging downloadable to computer for analysis and reporting

Instrumentation

Analyzers

Instrumentation

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Really low readings!

Analyzer / Calibrator

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The Other Analyzer

34 Leak Meter

Where does exhaust go?

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Where does exhaust go?

36 Through these!

Fume Hood Testing

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It is not just taking reading at the fume hood

You have to understand the entire

system

Fans, Filters, Controls, Etc.

NEBB

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Continuing Education and Research helps promote the knowledge and

invigorate the CP’s and CT’s to attain …….

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Computer Modeling

A major tool in the development of a more efficient laboratory as well as for containment vessels.

Plan View – Velocity Vectors (fpm)

Isometric Close-up – Velocity Vectors (fpm)

Isometric Close-up – SF6 Isosurfaces @ 0.05ppm

Summary of properties of FM200: Molecular Weight: 170.04 g/mole Molecular Formula: C3-H-F7 Boiling Point/Condensation: 15.6C (3.9F) Critical Temperature: 101.6C (214.9F) Vapor Pressure: 67 (PSIG) Specific Volume (ft3/lb): 18.9753 Gas Density (lb/ft3): 0.0527

Comparison of the spectra of FM200 and SF6

We finally had a chance to run the Case B fume hood using FM200 gas. The molecular weight for FM200 is around 175 and SF6 is around 146, therefore the FM200 will be about 20% more massive per liter of gas. We used equivalent mass as the injection rate not 4 LPM.

The FM200 concentrations are more spread out in the hood compared to SF6 even correcting for mass. May what to reduce the rate slightly more to achieve equal challenge.

FM200_pathlines

N2O_pathlines

CaseB_shortperson_FM200_3Dview_isosurface

CaseB_shortperson_FM200_3Dview_isosurface2

CaseB_shortperson_FM200_3Dview_zoom_isosurface

CaseB_shortperson_FM200_full_side_Concentrations

CaseB_shortperson_FM200_zoom_side_Concentrations

CaseB_shortperson_FM200_zoom_side_velocity

CaseB_shortperson_FM200_zoom_side_vorticity

FM200_ppm_3-5ft

N2O_ppm_3-5ft

FM200_ppm_5ft

What have we learned?

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The CFD modeling indicates that the

secondary side wall vortex's do not trap

lighter gas equal to heavier than gas.

All our testing have been with the

heavier gas so switching to a lighter

gas reduces the tracer gas challenge.

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By using CFD modeling we can determine exactly the

rate of heavier FM200 we will need to = SF6. The added

benefit we will be using less gas which is heavier.

NEBB Disciplines

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The constant changing technology requires each of the NEBB CP’s and

CT’s to persistently pursue the knowledge to maintain the preeminence of the NEBB’s

Leadership Role in the Industry.

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Questions or comments?