I have two stacked one on top of the other and can not even feel any air coming out of them when the DC is running.
The things I have experienced cutting air flow are :
90Deg. fittings, and "T's"
Flex duct, especially the type with ribs on the inside.
small flex,i.e. 2",2 1/2"diam.
ports smaller than the duct, requiring reducers.
any kind of fins in the ports to keep large chunks from passing
longer runs of ducts
The first Dc system I built was when they recommended the filters like an engine filter. Where the air blows from the inside out the filter was to be put into a box and the air blew into the box and then through the box to get out through the center of the filter which vented through a hole in the bottom of the box.The filer had a flange on the bottom of it that bolted to the bottom of the box. The top of the filter was capped so the air had to go through the pleats.
I made the box with a door on it and weather stripped tight when latched.
The first time I had to clean the filter because it was plugged up, it was a real chore. I swore, I would remedy this with the air blowing inside the filter and exhausting through the filter. Can you imagine cleaning the pleats on a vacuum cleaner filter 4' high and 16" in diam with the pleats packed with fine sawdust?
Last edited by Herb Stoops; 03-28-2017 at 06:13 PM.