Best Backdraft Damper

Draft Blocker - 4'' Inch Backdraft Damper Duct - Draft Stopper - Backflow Preventer - Inline Fan Vent - Vent Deflector (4'' Inch)

...eating ducts, vents and other HVAC applications.
INSTALLATION: The backflow flap is installed by inserting it into the ventilation pipe until it stops. The position of the spring should be horizontal for horizontal installations so that it can open and close optimally. The Backdraft shutter is installed so that the damper blades open only in the outflowing air direction..
The backflow flap opens and closes automatically at low air volumes. It has a smooth-running spring and an internal foam strip to keep the blades from rattling and can be installed horizontally or vertically.
Back draught valves can be inserted into ventilation ducts which are flexible or non flexible. Cannot be used with plastic ducts as the sizes are different. Size: 4'' Inch.

Lightweight valve wings: The valve wings open under the pressure created by the airflow and then automatically close with the spring work. The backflow flap closes automatically at low air volumes. The Backdraft shutter is installed so that the damper blades open only in the outflowing air direction.
Keep away from rattling: It has an internal foam strip and a smooth-running spring to keep the valve wings from rattling. The position of the spring should be horizontal for horizontal installations so that it can open and close optimally.
One-way airflow ducting insert: Back-flow valve with 2 spring-loaded wings prevents the reverse airflow movement through the ventilation duct when the ventilation system is turned off.
Material: The 4 inch Backdraft damper is made out of a Galvanized steel, the flap leaves are made of aluminum, while the Axis and spring are made of stainless steel and can withstand temperatures from 14 to 140 °F.
Wide applications: Back draught valves can be inserted into ventilation ducts which are flexible or non-flexible. Designed for use with range hoods, bathro....

4INCH HOUSEHOLD VENTILATION FAN - You may be aware excess moisture and muddy air lead to poor air quality and life quality. It is necessary to choose a high-efficiency exhaust fan with a backdraft damper for your room. This functioning ceiling wall exhaust fan can promote air circulation, take the muddy air away and maintain proper humidity and a healthy living environment.
HIGH-EFFICIENCY PERFORMANCE - The upgraded high-efficiency motor and stable fan frame can reduce the friction coefficient and operation noise, increase the performance of kitchen bathroom fan and savings in the electrical bill effectively. Ultra silent bathroom exhaust fan provides quiet and effective exhaust ventilation at 122 CFM to eliminate humidity, tobacco smoke, and cooking odors to keep your house smelling fresh.
SPEEDY EXHAUST & BACKFLOW-PROOF SHUTTER- MYGHKO exhaust extractor fan with light and thin backdraft damper sleeve, which can expand the exhaust opening angle for speedy elimination of turbid and moist air. A spring-loaded auto-closing damper valve can prevent smoke, debris, dust, and odors of the public flue from entering rooms.
BUILT WITH CARE - Our commitment to making things that last means we source materials carefully. The mainframe consists of a waterproof ABS ....

6 INCH HOUSEHOLD VENTILATION FAN - You may be aware excess moisture and muddy air lead to poor air quality and life quality. It is necessary to choose a high-efficiency exhaust fan with a backdraft damper for your room. This functioning ceiling wall exhaust fan can promote air circulation, take the muddy air away and maintain proper humidity and a healthy living environment.
HIGH-EFFICIENCY PERFORMANCE - The upgraded high-efficiency motor and stable fan frame can reduce the friction coefficient and operation noise, increase the performance of kitchen bathroom fan and savings in the electrical bill effectively. Ultra silent bathroom exhaust fan provides quiet and effective exhaust ventilation at 142 CFM to eliminate humidity, tobacco smoke, and cooking odors to keep your house smelling fresh.
SPEEDY EXHAUST & BACKFLOW-PROOF SHUTTER- MYGHKO exhaust extractor fan with light and thin backdraft damper sleeve, which can expand the exhaust opening angle for speedy elimination of turbid and moist air. A spring-loaded auto-closing damper valve can prevent smoke, debris, dust, and odors of the public flue from entering rooms.

Highest Rated Premium Airflow Control Backdraft Dampers.
Spring-loaded butterfly aluminum damper blades encased in a 20-guage galvanized steel housing.
May be installed in any position or orientation to prevent backflow and designed for use in AC, Heating, Vent and other HVAC application temperatures....
Extremely easy and secure inline duct insertion installation. Available in 4", 5", 6", 7", 8", 10", 12", 14" and 16"..
Minimal pressure to open. 0.04 to 0.08 in. w.g. Maximum automatic back flow protection.

【Material】The 10 inch backdraft damper and the flap leaves is made of a Galvanized steel, the Axis are made of aluminum, while the spring are made of carbon steel..
【Installation method】The position of the spring should be horizontal for horizontal installations so that it can open and close optimally.
【Wide applications】Back draught valves can be inserted into ventilation ducts which are flexible or non-flexible. Designed for use with range hoods, bathroom fans, kitchen and other home HVAC applications..
【Lightweight valve wings】The valve wings open under the pressure created by the airflow.
when the air flows in the opposite direction, it is automatically closed under the action of the spring, so as to cut off the flow..
【Backdraft Shutter】Hon&Guan Draft Blocker designed to improve ventilation by preventing air from re-circulating when the fans are not in use, rubber ring ensure 100% closure and quiet closing..

Highest Rated Premium Airflow Control Backdraft Dampers.
Spring-loaded butterfly aluminum damper blades encased in a 20-guage galvanized steel housing.
May be installed in any position or orientation to prevent backflow and designed for use in AC, Heating, Vent and other HVAC application temperatures....
Extremely easy and secure inline duct insertion installation. Available in 4", 5", 6", 7", 8", 10", 12", 14" and 16"..
Minimal pressure to open. 0.04 to 0.08 in. w.g. Maximum automatic back flow protection.