Heater teardown

Posted at 2017-10-14.

I was given an old fan unit with something rattling inside. These are not particularly expensive and it was a bit shady looking, so I decided to not turn it on, but just take it apart.

It has a nice-ish MDF or such case with a hinged front that I'll probably use for something. There was a power supply with, to my surprise, a high voltage output that went to a tight steel wire in the airpath. I presume that it's an ionizer. The other parts were some switches and a fan and a heater module. I took out the fan and heater by drilling out some pop rivets.

Amusingly the heater assembly seemed to be held together with hot glue. It turned out it's quite tightly sandwiched on some Al tube with spacers to separate the plates. Maybe the glue was for suppressing vibration. There's also a plastic(!) holder for the heating element. The heating element yields a bit of resistor wire and a nice stack of Al sheets and tube bits in the spacers.

The fan was a neat little radial cage fan with a short circuit motor pressed on and sort of integrated into the structure. I don't want to deal with the 230 V fan by itself, so I took the anchor part off and left the rotor in since that is essentially the axle/pivot for the fan. I parted and turned down a few pieces of the Al pipe that was used to hold the stack of plates in the heater to 18 mm or so. A little too low, it turns out, but adding a pair of washers made it possible to assemble the fan without its motor so it spins freely. No, I could make a new axle or just turn a groove or press a belt wheel on the rotor and add a little (BL)DC motor to run this. That should actually be useful to me somewhere.

The loose rattling piece turned out to be some broken plastic mounting hardware in the power supply.

I don't have pictures for this page, but I didn't want to put off writing down something. I've been quite busy with work and personal life lately and I don't even remember when I last turned the lathe on. Maybe I'll take some pictures of the parts someday. Maybe when I find use for them.