View Full Version : Air cleaner based on Bill Pentz design

Brian Deakin
12-12-2017, 10:55 AM
This is my air cleaner based on a Bill Pentz design


I have modified the design for stability by adding the four threaded rods which have acorns on their top ends and placed the unit on castors

I have placed a mesh above the fan for added safety and the purpose of the orange ribbon is to provide a visible indicator when the fan is running

The mesh is held in place with red cable ties and the perimeter of the mesh is a metal seal off a plastic drum

The two wooden shelves are braced for added strength

The fan is 230 watts and moves 11 cubic feet per second perhaps a little overkill but I was given the fan

If you decide to build a similar air cleaner based on the images below it is easier to assemble the unit by placing the acorn washer on the threaded rods first then tighening the nuts below the base

To clean the flter I turn the fan upside down reassmble the unit and run it outside

I apolozise for the images not being the correct way up I was unable to rotate them

regards Brian


Lasse Hilbrandt
12-12-2017, 4:55 PM
It certainly looks like it can clean som air. What kind of filter are you using ?

Brian Deakin
12-13-2017, 7:57 AM
I live in the United Kingdom I was given the Ventaxi fan which came out of a Rolss Royce factory in the Uk

The filter I purchaced off e bay for $30

This is the link for the filter


regards Brian

Art Mann
12-13-2017, 2:38 PM
Nice looking machine. An 11 ft^3/second blower is not overkill. That is 660cfm. Lots of the factory made suspended woodworking dust filters will do 1000cfm or more. I would say you have it about right.

Lasse Hilbrandt
12-13-2017, 2:54 PM
If I understand it right, the filter can only take particles down to 10 micron ? Im no expert, but I think I read somewhere that the filter needs to be able to filtrate down to 1-5 micron

Brian Deakin
12-13-2017, 5:20 PM

Please see chart on page 3

http://www2.donaldson.com/torit/en-u...ebbrochure.pdf (http://www2.donaldson.com/torit/en-us/product%20literature/productbrochures/ultra-webbrochure.pdf)

regards Brian

Brian Deakin
12-13-2017, 5:36 PM
Hi Art
The reason why I think it is over kill is I have single car garage with a total volume of 1600 cubic feet

( the house was built in the 1957 the garage is 8ft by 8ft and 25ft deep)

Therefore the fan filters the air the garage every 145 seconds or almost 25 times per hour


I did find the air cleaner very useful when decorating, I had to sand flat the plaster on a large hole I had filled

regards Brian

Art Mann
12-13-2017, 6:42 PM
Just keep in mind that a filter like that is extracting fine dust at the same time you lungs are if you are in the room. You need all the dust filtration power you can get. Any system that captures dust anywhere besides the source is capturing it too late for best results. Also, I think your assumption about how often the air is recirculated is optimistic. It is more likely some of the air is being filtered at much more than 25 times an hour and some much less so. That is another reason to have a powerful fan to stir up the stale and dust laden air. In my shop, the heater and filtration systems are placed so as to move the air in a circular fashion and maximize circulation.

Stephen Tashiro
12-14-2017, 9:58 PM
This is my air cleaner based on a Bill Pentz design


His eventual solution involved removing carpets and replacing them with tile. Anyone who has pulled up old carpets will understand why.