Louvers Selection Guide

A quick-reference table for choosing the right louver blade style, free area, pressure drop, and rain performance for common building applications.

Use this table as a starting point when selecting louver type for common building applications. Always verify requirements with your project's mechanical engineer and local code authority.

Application	Blade Style	Min Free Area	Max P-Drop	WDR Rating	Notes
General Ventilation	Drainable (4" or 6")	45%	0.10 in. w.g.	Class A	Standard HVAC intake/exhaust
Coastal / Hurricane Zone	Blade #1 (H.V.H.Z.)	35%	0.15 in. w.g.	Class A	TAS 201/202/203 approved; Miami-Dade & Broward
Parking Garage	Non-Drainable (6")	50%	0.08 in. w.g.	N/A	High free area for code-minimum ventilation
Mechanical Equipment Room	Drainable (4")	40%	0.12 in. w.g.	Class B	Balance airflow with rain protection
Architectural Screen	Custom Profile	30%	0.20 in. w.g.	Varies	Aesthetic-driven; coordinate with architect

General Ventilation

Class A

Blade StyleDrainable (4" or 6")Min Free Area45%Max P-Drop0.10 in. w.g.

Standard HVAC intake/exhaust

Coastal / Hurricane Zone

Class A

Blade StyleBlade #1 (H.V.H.Z.)Min Free Area35%Max P-Drop0.15 in. w.g.

TAS 201/202/203 approved; Miami-Dade & Broward

Parking Garage

N/A

Blade StyleNon-Drainable (6")Min Free Area50%Max P-Drop0.08 in. w.g.

High free area for code-minimum ventilation

Mechanical Equipment Room

Class B

Blade StyleDrainable (4")Min Free Area40%Max P-Drop0.12 in. w.g.

Balance airflow with rain protection

Architectural Screen

Varies

Blade StyleCustom ProfileMin Free Area30%Max P-Drop0.20 in. w.g.

Aesthetic-driven; coordinate with architect

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