1. Backdraft Dampers

2. Backdraft Damper Training Application Backdraft dampers allow air to flow in one direction only and prevent unwanted (hot/cold outside air, wind, etc.) from “back-drafting” into the building. They only install in ducts, at walls, or in roofs and open automatically when air flows in the intended direction and automatically close when there is no air pressure or when airflow is in the opposite direction. Basic Functions Intake/Exhaust Barometric/Pressure Relief

3. Backdraft Damper Training Intake Intake backdraft dampers allow supply airflow into a building while preventing conditioned air from escaping when the fan is off. Typical Applications Intake Air Duct - Wall or plenum mounted Intake side of rooftop evaporative cooler (requires counterbalance)

4. Backdraft Damper Training Exhaust Exhaust backdraft dampers allow air to automatically exit the building and prevent outside air from entering the building. Typical Applications In tandem with wall mounted exhaust fan. Exhaust air duct - wall or plenum mounted Roof top power ventilator Rooftop gravity ventilator Wall Mounted Exhaust Fan Backdraft Damper Roof Top Power Ventilator

5. Backdraft Damper Training Barometric Barometric relief dampers open automatically under low velocity conditions - including natural airflow - and close automatically to prevent reverse airflow. Typical Applications Rooftop gravity ventilator Wall mounted relief (no duct or fan) Backdraft Damper Roof Top Gravity Ventilator

6. Backdraft Damper Training Pressure Relief Pressure relief dampers use counterbalance weights to maintain a relatively constant upstream pressure, they open automatically at higher pressures and close automatically when pressures drop. Typical Applications Duct or plenum relief Room relief

7. Backdraft Damper Training AMCA 500D Test Requirements Test Samples Pressure drop: 12x12, 12x48, 48x12, 24x24, 36x36 Pressure Drop Ducted Inlet and Outlet - AMCA 5.3 Lowest Pressure Drop Ducted Inlet Only - AMCA 5.2 Plenum Mount - AMCA 5.5 (Highest Pressure Drop) AMCA 5.3 – Ducted Inlet & Outlet AMCA 5.2 Ducted Inlet AMCA 5.5 – Plenum Mount

8. Backdraft Damper Training Design Basics and Typical Application Light Duty Most common type and widely used for intake, exhaust, barometric, and pressure relief applications where air pressures and velocities are low (≤ 2 in wg. & 1250 fpm). Medium Duty Typically used for intake, exhaust, and pressure relief when pressure or velocity exceeds the light duty range (>2 in wg. & 1250 fpm, but ≤3 in. wg. And 2500 fpm. Industrial Employed when the temperature, pressure, or velocity exceed standard commercial damper limits. Units are typically flange mounted directly to the duct or fan housing.

9. Backdraft Damper Training Light Duty Backdraft Dampers Applications –BD-50 Gravity Intake and Exhaust Prop-Fan Exhaust Roof Top Power Ventilator –BD-51 Intake or Exhaust – where damper blade noise is a concern –BD-52 Evaporative Cooler – Discharge Side (down-flow only) –BD-54 Pressure Relief Mounting Arrangements –Vertical Mount –Horizontal Mount Up-flow Down-flow ( BD-52 Only ) Caution –Multiple Sections –Maximum Velocity & Pressure Limits –No Exact Pressure Settings Vertical MountHorizontal Mount Adjustable Counterbalance Weight Tie-Bar Integral Counterbalance Weight Channel Frame

10. Backdraft Damper Training Medium Duty Backdraft Dampers Applications –BD-60 Fan Exhaust - Duct or Plenum Mount –BD-64 Pressure Relief - Higher velocity Mounting Arrangements –Vertical Mount –Horizontal Mount Up-flow only Caution –Low-end velocity and pressure limits –No Exact Pressure Settings –Retarding Counterbalance Design Only - No assist to Open Vertical MountHorizontal Mount Hat-Channel Frame Concealed Linkage Adjustable Counterbalance Weight

11. Backdraft Damper Training Industrial Backdraft Dampers Applications –BD-84 Fan Exhaust - duct or plenum mount Mounting Arrangements –Vertical Mount only Caution –Low-end velocity and pressure limits –No Exact Pressure Settings –Assist to Open Counterbalance design only Channel Frame Concealed Linkage Adjustable Counterbalance Weight

12. Backdraft Damper Training Options & Accessories Flange Frame For flush mounting to equipment/wall Intake or discharge Sleeve 304 Stainless Steel Construction Electric Actuator (BD-58 Only)

13. Backdraft Damper Training THANK YOU!