Flapper Valve Description -- for  dropkick


Plastic film flapper valves on the upper vents during a collection period.  You can also see the hardware cloth that backs up the flapper valve and prevents it from being sucked through at night.




View of both lower and upper vents.  Since this is a shop area, I don't worry about making the vents or valves look pretty, but for a finished space, the flappers could be in the wall itself, and the vents could be covered with a grill.  Others who have built the collector have done this.

The picture below is a drawing of one such flapper valve built in the wall.





The same kind of vent could be placed in the lower vent if turned 180 degrees.


Hope this address your questions -- Gary Semptember 13, 2008