Yet Another DIY Air Cleaner

[Tarhead]

We're getting our new dual fuel heat pump installed tomorrow and I plan to scrounge the blower from our old system and make a shop air cleaner like a few others have done. After visiting Don's (Touchwood) shop last year I was impressed with his set up and want to duplicate a feature he has. http://ncwoodworker.net/forums/f81/another-air-cleaner-12954/

I you look close he has installed a pressure gauge on his box to tell when to clean/replace his filters. As the filters get clogged more negative pressure builds inside the box (or Coffin in his case:wsmile: ) I am looking at making a water manometer similar to the one below I modified from a site discussing engine building. Has anybody done this or have any ideas how long the loop needs to be? Don mentioned a 2" drop in pressure indicating a full filter on his.
Thanks!

 

[Alan in Little Washington]

It depends on the SP capability of the motor/fan unit which is usually expressed in inches of water.

You can test it easily, by starting with a big loop, connecting it to the blower box and almost totally blocking off the intake. That will be your worst case and show you how big of a loop you need.

Remember, you will suck the water right out of the tube unless you have a really big loop, really large diameter tubing, one end is blocked, or both ends of the tube terminate in the box- one at a static port (just an opening), the other connected to a "pitot" tube that faces into the air flow. There is plenty of info on manometers on the web.

Also, you get more fidelity if you mount the tube at an angle, such as 45 degrees.

 

[Touchwood]

We're getting our new dual fuel heat pump installed tomorrow and I plan to scrounge the blower from our old system and make a shop air cleaner like a few others have done. After visiting Don's (Touchwood) shop last year I was impressed with his set up and want to duplicate a feature he has. http://ncwoodworker.net/forums/f81/another-air-cleaner-12954/

I you look close he has installed a pressure gauge on his box to tell when to clean/replace his filters. As the filters get clogged more negative pressure builds inside the box (or Coffin in his case:wsmile: ) I am looking at making a water manometer similar to the one below I modified from a site discussing engine building. Has anybody done this or have any ideas how long the loop needs to be? Don mentioned a 2" drop in pressure indicating a full filter on his.
Thanks!

Mark

This is the one you saw in my shop

http://www.amazon.com/Dwyer-Molded-...ref=sr_1_1?ie=UTF8&s=hi&qid=1241986630&sr=8-1

I don't remember it being that expensive when I bought it..but it sure takes out all the guess work.

Dont know why you couldn't copy their design ...like [STRIKE]McRabbet[/STRIKE] Alan in Little Washington says you get more accuracy by having the tube slanted. Mine started leaking, so I replaced the gasket in the fill hole and used that red colored gas stabilizer stuff..works as good as manometer oil as far as I can tell.:icon_thum

Don

"Don't sweat the petty things, and...

Don't pet the sweaty things"

 

[Mark Stewart]

I am in the process of building my air cleaner and I would like to know about the filters you guys are using. What type and where are you buying them? I havent seen them any where except at work?

 

[Tarhead]

Mark,
Don mentioned Global Filters in Raleigh http://www.healthyhomefilters.com/about-global-filters.html but didn't specify which filters.

I'm also looking at JDS internal pocket filters: http://www.woodworkingshop.com/cgi-...ST COLLECTION FILTERS&qryType=GRPSG&group=DCA

and PennState: http://www.pennstateind.com/store/air-cleaner-filters.html

I'm planning to use a pre-filter and either a pocket or large pleated filter inside. I would like to see if there are any more options and sources.