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5. TROUBLESHOOTING TIPS
Failure of HERS testing may be caused by a number of factors.
Here is a list of troubleshooting tips to assist in detecting some possible causes of HERS
failure that pertain to this testing equipment, and apparatus.
• If it is ducted whole house fan, examine ductwork for improper installation including too
sharp of a bend, too many bends, excessive length or any obstructions on exhaust side of
fan
• Verify that the WFH-PFH hood does not have any rips or tears on the fabric
• Verify the airflow measurement taps in the hood are not in path of the airflow
• Verify all tube connections are properly connected for airflow measurement apparatus and
hood adapter system.
• Ensure proper connection of the WHF-PFH flow hood to testing fan apparatus has a tight
seal at the collar to fan connection. Leakages at the collar will produce inaccurate results,
and may not allow the hood to reach 0 Pa required for HERS testing.
• Ensure proper connection of the WHF-PFH flow hood to ceiling has a tight seal at all four
corners of the hood. Leakages at the hood to ceiling connection may produce inaccurate
results, and may not allow the hood to reach 0 Pa required for HERS testing.
• Be sure to use calibrated airflow measurement apparatus when performing HERS testing.
Refer to manufacturer manuals for keeping calibrations current.
