I have a simple question. Why do all the plans for homemade air cleaners require squirrel cage fans?
Could you use multiple large "muffin" fans to accomplish the variable speeds (ie., 1 fan on for low, 2 fans for med, and 3 fans for high)?
I have a simple question. Why do all the plans for homemade air cleaners require squirrel cage fans?
Could you use multiple large "muffin" fans to accomplish the variable speeds (ie., 1 fan on for low, 2 fans for med, and 3 fans for high)?
Last edited by Anthony Whitesell; 02-11-2011 at 10:28 AM. Reason: Can't type
The centrifugal type fans seem to operate better when there is resistance to the airflow (like what a filter and a reducing hose introduces in an air cleaning system). I believe the axial or propeller fans operate best without resistance. So, yes, you cld probably use some large propeller fans, but I guess the squirrel cages offer better bang for the buck and size.
FWIW, I made a squirrel cage filter that works well. I also have a $12 box fan from HD which has a 20x20 furnace filter bungied to the intake. It's light and portable and quiet and *I can take it right up to my work* (this overcomes a lot of its power limitations). It too does a great job when I have to sand indoors.
If yr cleaner has to be stationary, though, I'd probably get a squirrel.
What is a marge muffin fan?
Trying to follow the example of the master...
Muffin is a colloquial term for an axial fan. Prashun is correct is stating that axial fans are not designed to operate against a high resistance (static pressure). The achievable airflow and efficiency of axial fans drops significantly against a high back pressure. In commercial/industrial applications, axial fans are commonly used to provide air exchange between two open volumes. eg. from inside a factory to the outdoors.
New Canuck Workshop
The two items are that the squirrel cage fans usually are rated for much higher volume of airflow and also that they remove the motor from the airstream. With the muffin fan, the motor is right in the airflow and subject to all of the dust that you are working with.
Muffin fans tend to collect a lot of dust of the blades. Look at your computer power supply fan sometime.
Never, under any circumstances, consume a laxative and sleeping pill, on the same night
I have a cleaner made with a gable fan. It is rated at 1600CFM and does only an only OK job through the filters. My dad's squirrel unit does a superior job through better filters and is much quieter. I think it is a matter of a better suited unit for the job at hand.
"A hen is only an egg's way of making another egg".
– Samuel Butler
With filters pre and post, I would hope that wouldn't be an issue.
I was just wondering, because I found some ~1000CFM 8" diameter axial fans for $10 each, but I haven't been able to find an inexpensive source for a 120V (found lots of 220V, 208V and 440V 3PH) squirrel cage fans.
Okay so now I know what a muffin fan is. What does "marge" mean, or was that a typo?
Trying to follow the example of the master...
Looks like it was a typo.
It now reads "large."
I rather liked it better the other way
I didn't see if this was mentioned: typically the noise of squirrel cage units is much less than the other type (for the same amount of CFM).
So if you plan to have that running all the time you might get really tired of the noise (as a comparison check the range-hoods that have the two
types and compare their noise level).
Being the pack rat that I am I have had some muffin fans laying around for some time collecting dust and decided to try to put them to good use. they were originally used to exhaust hot air from a motor controller. The box is 1/2" MDF and each fan draws .25 amps and uses 2 filters. I originally designed it to hold 3 filters but nothing ever made it that far so the fan blades do not need cleaning. the first filter gets changed every .4-6 wks and the 2nd filter about 3 mo. It runs continuous so I found no need for a timer as it only draws 1amp total
Don Z
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Last edited by Don Zielinski; 02-11-2011 at 3:17 PM. Reason: spell check
Anthony.... How would you stop the outflow through the "off" fan(s) when it was running on low (one of three fans) or medium (two of three fans)?