How can a clogged louver bird screen collapse an intake louver?

Field answer

A bird screen loaded with leaves, plastic, or debris can become the real damper in the system. A big fan can pull enough negative pressure to bend blades, collapse weak frames, or damage the intake assembly.

Stop the fan if the louver is deforming. Clear the obstruction only when safe, document damage, and replace any bent louver sections. For high-consequence intakes, review maintenance access, stronger screen/louver construction, and pressure monitoring/shutdown controls with the foreman/engineer.

What to check first

• 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.

Why it matters

Blocked intakes can damage the louver, starve the system, and create building pressure problems.

Ask foreman

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Related Field Rescue route

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Final direction belongs to the foreman, approved drawings/specs, manufacturer instructions, pressure/material schedule, employer policy, and AHJ/code requirements.