I have an Electronic Air Cleaner built-in in my furnace/air conditioner since I bought this property. Recently I have a duct cleaning company to do a thorough duct cleaning. The guy pulled out my Electronic Air Cleaner insider units not to use again, instead, he put a paper filter there. He told me Electronic Air Cleaner is just a joke, cannot do the job; and told me don't put them back in, just change the paper filter every three month. I wonder is there any expert can tell me is the true? Thank you.