In-Situ Filter Testing ASHRAE GPC 26 In-Situ Filter Testing

In-Situ In Original Position In Place As Installed

Full Name of Guideline Guideline for Field Testing of General Ventilation Filtration Devices and Systems for Removal Efficiency In-Situ by Particle Size and Resistance to Airflow

Easy and User Friendly

Purpose Provide test procedure for evaluating in-situ performance of: Removal Efficiency of Filter Devices Removal Efficiency of Filtration Systems Resistance to Airflow

Scope For General Ventilation Air Cleaning Devices in their End Use Installed Configuration Site Conditions must meet Minimum Criteria Not Intended for : HEPA or ULPA Filters Portable Air Cleaners

Test Equipment Particle Counter Pump Sampling Probes and Lines Valve 3 Range Minimum .3 to 5 Micron Size Range Pump Sampling Probes and Lines Valve Air Velocity Instrument Relative Humidity Instrument Temperature Measuring Instrument Pressure Drop Gauges

Equipment Setup

Procedure Record Conditions Take Fractional Efficiency Data Velocity Humidity Temperature Pressure Drop Visual Inspection Take Fractional Efficiency Data

Fractional Particle Efficiency Data Filter Efficiency Upstream probe within 24” Downstream probe centered within 12” Filtration System Efficiency Upstream same as above Downstream probe – in front of next component Other “System” Test – across desired components –(pre, coils, fan, final)

Sampling Probe Setup

Sampling Method Zero Particle Counter Concentration Limit – Dilute if over 50% of instrument limit Isokinetic Flow – within 20% Prescreen Particle Concentration for Variability – 2 sets of 5 samples within 25% Take Samples

Samples Alternating Upstream/Downstream Number of Samples Purge between counts Number of Samples Minimum of 4 upstream and 3 downstream for each range More to lower uncertainty Sample Volume Greater of 20 seconds or 1 liter

Calculations of Fractional Efficiency

Reporting Results General Information Which Filter Tested Number and Type of Filters Dimensions of Duct Schematic Drawing showing Location of Sample Points Equipment Used When Filters were Last Changed Other Observations

Reporting Results (Cont.) Airflow Relative Humidity Temperature Pressure Drop Fractional Efficiency

Challenges Isokinetic Flow Turbulent Flow Repeatability of Test Operator Error or Inconsistencies

Timeline Final Draft by ASHRAE – Quebec Review ?????

Questions