A clogged bird screen makes the intake louver collapse inward
A blocked screen can make the fan pull hard against the louver. Shut the fan down, clear/replace the screen and damaged louver, and review maintenance or pressure safety controls.
Do not run a large supply fan against a blocked intake screen and hope it clears itself.
Check
Check screen condition before startup and during seasonal debris periods.
Look for blade deformation, frame bowing, or suction noise.
Confirm the fan is not running against a blocked intake.
Document debris and louver damage.
Ask about screen maintenance and pressure safety controls.
Steps
Check screen condition before startup and during seasonal debris periods.
Look for blade deformation, frame bowing, or suction noise.
Confirm the fan is not running against a blocked intake.
Document debris and louver damage.
Ask about screen maintenance and pressure safety controls.
Say this to your foreman
The intake louver at [location] collapsed inward after the bird screen clogged with debris. I shut down/held startup and documented the blockage. Do you want replacement louver sections and pressure/screen maintenance review?