Need some Incubator advice - Controlling CPU fan speed.

[seang89]

Because the fan speed has everything to do with how stable the temperatures are shelf to shelf, that and our fan is a lot larger bathroom ceiling fan and had to be slowed down.
If the fan runs too fast it makes the bottom of the incubator hotter than the top

Micro-managing the fan lets me dial in all 3 shelves to the same temperature.
We fought shelf to shelf temperature differences until plugging the fan into a rheostat.

Our incubator is a 24 cubic ft. true cooler and for now we use 3 shelves that will hold six 7qt tubs. To get the same temperatures on all three shelves we just move the fan speed up and down until the temps are equal on all shelves.

Bathroom ceiling fan plugged right into a zoo-med rheostat facing backwards to blow against the back of the inc.


Sorry, I do not know how to do the same with a computer fan

Thank you. This shed some light on my situation. It seems that rheostat I posted earlier is what I need. Lucky its the right wattage I need to, its the only type of raw rheostat I can find right now.

[OhhWatALoser]

Ive looked into dimmers(heard this is a No-No for fan speeds), rheostats(cant seem to find anyone that sells them in Toronto Ontario, CAN.)

I just noticed, you do know most cheap light dimmers are rheostats.....

[88Snakes]

I ended up wiring a CPU fan to an old answering machine transformer and then simply plugging that into my Herpstat. My thought process was that the fan speed would be regulated by how much demand there was to increase the temps throuigh the Herpstat. So far I've hatched 7 out of 8 clutches with no issues

[88Snakes]

And as far as buying CPU fans .... Just head down to a small computer repair shop and ask for a couple differant CFM CPU fans. They will likely give you several used fans for just a couple dollars if not for free. I picked up 5 differant fans locally for free. They were only ask 50 cents to $2.00 for them but after I explained to them that I wasn't sure what CFM I wanted they just gave them to me.

[llovelace]

And as far as buying CPU fans .... Just head down to a small computer repair shop and ask for a couple differant CFM CPU fans. They will likely give you several used fans for just a couple dollars if not for free. I picked up 5 differant fans locally for free. They were only ask 50 cents to $2.00 for them but after I explained to them that I wasn't sure what CFM I wanted they just gave them to me.

Thanks for sharing that, good to know

[seang89]

I just noticed, you do know most cheap light dimmers are rheostats.....

Have you tried yourself using a cheap light dimmer to get it work with a fan? It doesn't work. Not the way I am inquiring about. The dimmers you buy for regular household use are rated for a certain amperage, It wont work on this small scale cpu fan.

What was the point of telling me this? Got any other info?

[OhhWatALoser]

Have you tried yourself using a cheap light dimmer to get it work with a fan? It doesn't work. Not the way I am inquiring about. The dimmers you buy for regular household use are rated for a certain amperage, It wont work on this small scale cpu fan.

What was the point of telling me this? Got any other info?

as a matter of fact I have used a light dimmer on cpu fan before, common 120mmx120mm, way back in 5th grade. part of a rube goldberg machine

amperage doesn't matter one bit, rheostat is just a variable resistor, they come in different ranges of resistance, I don't know the specs of the rheostat or fan your trying to use or what range a common dimmer is, but you broadly say rheostat, which light dimmer falls under that category. hence my confusion on why you said it wouldn't work. sorry for trying to help, ill be quiet now.

[seang89]

as a matter of fact I have used a light dimmer on cpu fan before, common 120mmx120mm, way back in 5th grade. part of a rube goldberg machine

amperage doesn't matter one bit, rheostat is just a variable resistor, they come in different ranges of resistance, I don't know the specs of the rheostat or fan your trying to use or what range a common dimmer is, but you broadly say rheostat, which light dimmer falls under that category. hence my confusion on why you said it wouldn't work. sorry for trying to help, ill be quiet now.

Maybe dimmers that had variable transistors worked with the fans back in the what? 90's? but today, they only use the variable transistor as a mechanism to make the overall dimmer work the way want it to ( to not waste energy/cause unwanted heat). So the variable transistor doesn't complete the dimmers main funtion, just aids it.

So when I said Dimmer, I meant what common people know as a light dimmer.

When I said rheostat, I meant Potentiometer/Variable Resistor/Rheostat. There is and isn't a difference, it depends if you play semantics or not.