How do the blades of my plastic “Blizzard” electric fan get so dusty? I know the fan is sucking in air, and dust, from the back, but the blades are spinning so fast. Yet more dust accumulates on them than other objects in the room that are stationary.
I think Cecil may have answered this a long time ago. As I recall, the spinning fan blade accumulates a static charge, which is what attracts the dust.
Indeed. Spinning (plastic) blades generate static by the friction generated from moving all that air. Static attracts dust. Ergo, spinning blades = dust magnets.
IIRC, if the blades were aluminum, you wouldn’t have that problem since aluminum is conductive and as such would simply discharge the static itself.
I don’t know the answer to the OP, but I do HVAC work for a living and I see fan blades of all sorts that are dusty/dirty/filthy. Including aluminum.
My wooden ceiling fan blades get really dirty unless I clean them regularly. I had one fan that I left running constantly. I was shocked when I turned it off because I would have guessed that the constant motion would have kept the dust from settling. I would have guessed wrong.
Agreed. I work with fans that move millions of cubic feet of air (or gas) a minute, made from all sorts of conductive materials, and they get dirty too. It’s just something you have to accept, and you clean them when they’re in an outage (mainly for anti-corrosion purposes).
Ash-laden gas fans won’t get as dirty as air fans because the ash “sandblasts” the fan blades clean. However, it does also wear the blades down, to the point of breaking off pieces that fly through steel housings, ripping through a cable tray and shorting out a transformer, causing a 250MW unit to trip, power outages locally, then riots and madness and buggery… 
I don’t know about fan but extreme dust buildup can ruin the ability of a squirrel cage blower to move air. I didn’t even think of this and after we had been living in our house for 10 years or so I noticed that the heater wasn’t warming things up very well. I grumbled and did nothing. Then the next winter not only wasn’t the heater working well but the blower sounded noisy as if it had gotten out of balance.
So I finally too a look in the furnace and there was about 1/8" buildup of dust on the blower. I took it out of the furnace, cleaned it and voilà, it worked like new.
I now clean it every other year.
I’m sorry - is this a feature, or a fault?
I’m trying to remember notes from my Buffalo Forge handbook, but I think squirrel cage fans are especially subject to dust buildup because of the relatively narrow gaps between the blades, as well as the low rotational speed. Those are good candidates for routine cleaning, certainly.
Let’s just say it means more work for me…which is normally good.
I’d much rather work with lotsa routine maintenance than one catastrophic repair. The pieces go back together much easier. 
And I always thought that the reason I had to clean the ceiling fan blades was caused by “dead-air” on leading edge low pressure side of the blade. I didn’t know it was an “electro-static” situation.
Besides the static effects that gets dust to cling to the fan blades, there is a quantity component.
Almost all the air will eventually pass thru the fan blades. The fan is places centrally, and the airflow is intended to cause the air to circulate thru the fan. That’s not true for the furniture in the rest of the room – that only gets touched by the air going thru that part of the room.
So just from volume of air alone, the fan gets touched by a lot more dusty air than the rest of the room furnishings.
I’m picturing the only good scene from Alien 3 here…
And gets dusted a lot less frequently. These two concepts, combined, are the answer.
If it bothers you, you could dust it periodically with a canned dust blaster - use the straw attachment to get through the casing of the fan and close to the blade (make sure everything’s unplugged first, of course).
Nah. What you need to do is spend $300 for a small air compressor. You can clean all sorts of things. or at least move the dirt around.
hell if you want it clean you can wash it with warm soapy water. (unplug it first)
it will have to sit for a week or 2 to dry out the coils but I have a fan thats been through the hose several times with no ill effects other than me dropping a bit of machine oil into the spinny parts after its dry.