Thoughts for fan and controller to move a whopping 1 cfm

We need to move a small amount of air and provide a controller for the fan speed. We want to use a simple axial fan. In looking at some circuits, I think AC control will be easier to do but but really hard to find AC fans this small that have a design voltage of 120VAC. most that I find this small are 12VDC.

Just curious if you guys think a DC controller can be slimmed down to be super simple (cheap) or if we are better of trying to shop for a small, AC fan?

a simple potentiometer in serie with a small 12v fan would do the job since it is very low power

I would go for the DC fan - such fans will run on less than 12 VDC, many will run down to almost 5 VDC; you could use a simple potentiometer wired as a voltage divider to control them (many cheap PC fan controllers work this way). If you need to be able to run the fan slower, then PWM of the 12VDC power to the fan could be used. Use a 555 timer controlled by a potentiometer running as an astable multi-vibrator; the output of the 555 would be fed to control a transistor or mosfet to switch the 12 VDC to the fan. Total cost of parts for either should be around/under $5.00 USD...

I was trying to avoid a reg/rect circuit for low VDC. Do they make small AC fans comparable to the PC type DC fans?

Small AC fans do not seem to be available for whatever reason.

Just use a film (non-polarized) capacitor connected in series with the AC into a bridge rectifier to generate the DC. Select the cap size to give the voltage you need at the current draw of the fan.

You can use a pot connected as a rheostat in series with the motor to adjust its speed.

If you don't need continuous adjustment, you could also adjust the fan speed in steps by having several caps and selecting the number of caps are in parallel with a switch to change the speed (the more caps in parallel, the higher the speed).

I was trying to avoid a reg/rect circuit for low VDC

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You can use a wall wart (power pack) and the smallest value pot (potentiometer) you can get like 1000 ohms or less. Andy