I purchased an Electronic Air filter to replace my standard HVAC filter. The filter came with a 24V transformer that plugs into a standard AC outlet, but it has been recommended to me to wire it directly to the 24V transformer on the HVAC controller so that it is only "on" when air is blowing past it. (In addition, I don't have an AC outlet in the room, so I have an extension cord running across the floor!)
Which wires can I tie this into so that the filter will receive power when the fan, and/or, the Heat/AC is on?
Thanks for any help.

I have no idea what kind of furnace you have but some of the later furnaces (10 to 15 years) have a terminal you can connect to for a air cleaner. There should be a wiring diagram on the door of the furnace or you should have a home owners booklet.

Thank you so much! After closer inspection I did find the optional Air Filter hookup!

I have a Climatec air filter 24 vac/DC 2 watt Model 1000/2000. 14 X 20. I'm not sure the static charge is working. I change the filters which are not really dirty,
When first installed I use to hear snapping as the filter worked. I now hear nothing. Is there any way to operationally check to see if the charge exists between the charged middle screen and the two outer?