Filters for Vac enclosure

[aschutsky]

What type/size filters are you all using for your vac enclosures? I picked up a rigid shop vac filter for which I'm planning to make an enclosure to house it. The nice part is a 4" PVC pipe fits right into the opening. My main concern is this being a restriction with my four 7123 lighthouse motors. Thoughts?

Here is the filter I'm planning on using:

http://t.homedepot.com/p/RIDGID-1-Layer-Pleated-Paper-Filter-VF4000/100021159

[coryatjohn]

I use two shop vac filters (one per side). When you think of how much actual air is flowing through a hold down system, pretty much any air filter at least the diameter of the airline should be sufficient.

[gundog]

Why do you need a filter? Are you pulling vacuum through a spoil board? I can't imagine the filter is any better than the spoil board for filtering particles out. Maybe I am missing something in your design.

[aschutsky]

I use two shop vac filters (one per side). When you think of how much actual air is flowing through a hold down system, pretty much any air filter at least the diameter of the airline should be sufficient.

So you are running one on the inlet and one on the outlet? Interesting, that's a fair amount of surface area. Being an automotive guy, the fact that I've run 600-800hp through a 4" intake should say something as well. :D


Why do you need a filter? Are you pulling vacuum through a spoil board? I can't imagine the filter is any better than the spoil board for filtering particles out. Maybe I am missing something in your design.

Yes, I am indeed running a spoilboard, but I thought best practice on here was to feed them filtered air to get them to live the longest? I'm sure there is always some debree from the table and pipes that could get sucked in there. It's very simple and cheap insurance from my perspective as long as it doesn't kill my airflow.

[dlcw]

Yes, I am indeed running a spoilboard, but I thought best practice on here was to feed them filtered air to get them to live the longest? I'm sure there is always some debree from the table and pipes that could get sucked in there. It's very simple and cheap insurance from my perspective as long as it doesn't kill my airflow.[/QUOTE]

I've been running 4 of the Lighthouse vacuum motors since 2009 and do not have any filters. I've not had any problems at all. I use some butterfly valves connected via flex tubing right to the main vacuum line to let in the correct amount of air for cooling. Again, no problems since 2009.

I thought about filters but at my shop altitude of 2500' I need as little resistance to air flow to get as much vacuum as possible.

[aschutsky]

Don - Thanks for your input. I'm assuming the amount of debris that would enter the motors would be minimal with most of it being sealed off, but I thought I had read by Brady and others that filtering was highly recommended. I could be wrong though.

[aschutsky]

Guys - some quick experimentation revealed I'm losing ~1.5" HG using my filter box. It's a smaller box (15"W x 18"D x 12"H) using a single Rigid shopvac filter. Has anyone else measured loss through a filter box?