Thread: Fan Speed help in home made air filter

Joe, I'm no sparky but I do know that: (1) it's not possible to control all types of motors with a variable resistor or dimmer and (2) most motors are designed to run in a certain speed range and do not take kindly to being run for extended periods at markedly reduced speeds as they tend to overheat. Possibly if you have model numbers etc. you could check with the manufacturer or distributor.

Mick

Joe,

Like Mick, I am not a sparky but I am real sure you wont be able to slow that sucker (pun intended) down using a dimmer or speed control. As Mick said, it will probably burn it out.

However, you could just make the inlet smaller by blocking it of a fair bit. This will reduce the air available and therefore the suction.

Just a point about Air Filters though - Air Filters pick up the nice fine dust AFTER you have finished breathing it in to your lungs. A good Dust Collector (and ducting/hoods/etc) is much more preferable as it picks up the stuff right at the source. Nothing to breath in then and the shed stays nice and clean(ish) to boot.

Hi Joe

That is a single speed induction motor. That means you can't use a dimmer for speed control. (Definitely)
Two reasons - 1. That type of motor is designed for a particular voltage/amps/speed, it is an inherent part of the design of those motors that they synchronise to the AC waveform, the speed can't be varied. 2. A dimmer is generally rated at 500 watts, that motor is rated at 4 amps which at 240 volts is about 1000 watts. So you'd cook the dimmer.

That type of fan is a "blower" fan not a "sucker" fan, I doubt it could be used as a dust extractor, if you did it would have the dust etc going through the blades of the fan and they look a bit light for that.
It's a nice blower though, suit central heating/airconditioning, or a mega rangehood that would suck the peas right out of your saucepan...
Chris

Or you could use it to power a cyclone... the heavy stuff gets trapped in the bottom before the blower/sucker and the fine stuff gets trapped in the final filter after the sucker... ?

Thanks for all the feedback.

I didnt think a dimmer would work, thats why I thought I'd double check.

I'll box up the blower and play around with inlet sizes, I think that is my best option. I'll post my results if people are interested.

I am going to run this in addition to a dust collector, I just want to cut down on the airborn dust as much as possible.


Thanks
Joe

Joe,

Regarding Chris's comments - even though it is designed as a blower of course you can still use it - just put the Filters in front of the air inlet thereby causing only (relatively) clean air through the Fan. Make sure you do it this way otherwise the fan blades will get blocked up with dust/crap/etc. very quickly.


Len,

No good for a Cyclone imho - motor is to small. You really need 2hp+ to make them work properly even with that cage type impeller/fan.

Joe,

I picked up and old evaporative aircooler with a 3 speed fan that is working very well and want to build into an air filter. This will be in addition to my dust collector system.

So I am wondering how did you go.

Did you use any filters and where did you get them.

Peter.

Airconditioning mechanic used to supply us with filter medium that we would put into ordinary screen aluminium (the stuff screens for windows are made out of). This stuff traps quite a lot of gunk.

There's one idea.

Hi Sturdee.

I haven't had much time to work on the air cleaner, so its still in pieces (hopefully this weekend).

I have decided on building a little unit on casters so I can move it around the workshop while I work. Once I figure out how to best use it I'll mount it in the ceiling.

I picked up a filter from Carbatec in Melbourne. They are new replacement filters for the comercial units they sell. They cost about $25.

I figure if they are the same ones in commercial units they will work just as good for me.

They are perfect for the job, they come in a solid cardboard frame (don't remove the filter its glued in) you simply fix the airfilter to your box and its done. The other good thing is that because they are a standard filter you should be able to replace them as needed.

Hope this helps

Joe