501F/G Technical Presentation

Evaluating GT Inlet Filtration Options and Understanding

Filtration Efficiency Ratings

Presented By: Barry Link

Manager, GTS Aftermarket

Donaldson Company, Inc.

11:05 AM – 11:35 AM, Room #2

Monday February 13, 2012

Presentation Objectives

1. Review the key factors that should be

understood when evaluating GT inlet filters.

2. Explain the filtration efficiency ratings for

today’s accepted standards - ASHRAE 52.2

- EN779

- EN1822

3. Leave you with a reference tool to help

remember key points from each standard.

4. Address any questions.

Your Inlet System

● Pulse vs. Static

● Turbine inlet airflow (800,000 – 890,000

CFM)

● Type of filters • Panel filters

• Canister type filters

• Cylindrical filters

• Cylindrical/cylindrical pairs

• Conical/cylindrical pairs

● Number of air filters/filter pairs

● Airflow per filter/filter pair (Turbine inlet

airflow divided by number of filters/filter

pairs)

Your Application

● Operating mode (base, intermediate, peak)

● Inlet operation mode (pulsing operation)

● Environment

• Temperature

• Moisture (coastal, rain, fog, mist, snow, sleet, cooling

tower drift, etc.)

• Hydrocarbons

• Dust concentration

• Local or seasonal airborne contaminants (pollen, cotton

seed blossom, agriculture processes, industrial

processes, etc.)

Filter Construction Materials

● Media • Glass fiber

• Cellulose

• Cellulose & Synthetic blend (blended media)

• Nano-fibers (Donaldson Spider-Web®)

• Membrane (ePTFE)

• Spun bond

• Melt blown

Data from Industry accepted

Testing Standards ● Resistance to airflow

• Filter type and configuration

• Test airflow rate (flow per filter/filter pair)

● Filtration efficiency (initial or average) • Initial efficiency (initial is not always minimum; static

charged filters)

• Minimum efficiency

• Average efficiency

• Initial efficiency @ most penetrating particle size

Industry accepted Testing

Standards ● ASHRAE52.2

● EN779

● EN1822

Industry accepted Testing

Standards

Blower

Filter Element

in test

Aerosol

Generator Sample

Probe

Sample

Probe Manometer Manometer

Dust

Feed HEPA

bank

HEPA

bank

Flow

Nozzle

Final Filter

Airflow

● Element Pre-Treatment (IPA dip/mist)

● Resistance to Airflow

● Filtration Efficiency/Particle Removal Efficiency

• Challenge aerosol (KCL or DEHS)

• Initial and/or Average Efficiency

• Dust loading

ASHRAE52.2

● Resistance to airflow • Measured at 25%, 50%, 75%, 100%, & 125% of test

airflow

● Aerosol (challenge aerosol) • Dry potassium chloride (KCI)

● Filtration Efficiency • Initial efficiency; average of “E1” category

● Efficiency Rating • MERV (minimum efficiency reporting value)

● Element Pre-Treatment • None

● Dust Loading • ASHRAE dust to 4.0”WG

ASHRAE52.2

EN779

● Resistance to airflow • Measured at 25%, 50%, 75%, 100%, & 125% of test

airflow

● Aerosol (challenge aerosol) • DEHS Neutralized (oil)

● Filtration Efficiency • Average efficiency (initial & loaded) up to 1.8”WG

resistance (6 points, initial plus 5)

● Efficiency Rating • “G”, “M”, “F”

● Element Pre-Treatment • Historically none; IPA with 2010 standard

● Dust Loading • ASHRAE dust to 1.8”WG

EN779

EN1822

● Resistance to airflow • 100% of test airflow

● Aerosol (challenge aerosol) • DEHS Neutralized (oil)

● Filtration Efficiency • Initial efficiency @ most penetrating particle size

(generally 0.1µ)

● Efficiency Rating • “E”, “H”, “U”

● Element Pre-Treatment • Historically none; IPA with 2009 standard

● Dust Loading • None

EN1822

Summary

Summary: Filtration Efficiency Measurements

Conclusion

● It is very important to understand your inlet,

application, & environment when choosing

GT inlet filters.

● 3rd party ASHRAE52.2, EN779, EN1822

reports can offer valuable information to

help compare filters.

● Understanding how factors such as static

charged filter media can effect test results is

very important.

● Input from fellow users and reflecting on

past experience is also good information to

help make good filter selection decisions.

● Leverage key industry resources.