Dampers shutters and louvers are used to create zones prevent backdrafts and direct airflow in ventilation systems.
Roof fan spring loaded shutter.
Shutters are spring loaded to automatically close when the fan turns off.
Ac infinity airlift t12 shutter exhaust fan 12 inch with temperature humidity controller wall mount ventilation and cooling for sheds attics workshops.
12 w x 12 h.
Make sure the shutters have a spring and it is connected properly.
Iliving 18 wall mounted exhaust fan automatic shutter variable speed vent fan for home attic shed or garage ventilation 1736 cfm 2600 sqf coverage area 4 6 out of 5 stars 190 130 69 130.
These gravity operated exhaust shutters can be used with direct or belt driven exhaust fans and can help prevent air backflow when the fan is off.
Spring loaded for positive closure.
3 8 out of 5 stars 147.
Battic door whole house attic ceiling fan shutter seal cover fits up to 36 x 48 attic fan shutters.
Heavy duty motorized volume control damper.
If the spring is there but the tension is insufficient move the spring up a notch to increase the tension.
Quietcool accessories 14 in x 30 in metal galvanized steel whole house fan shutter.
This enables the shutters to close when the fan turns off.