This is a split system heat pump with the return air chase at the bottom of the air handler in a hallway closet. The unit was working properly but there is quite a bit of dust accumalation in the return air plenum and one filter installed and one filter missing.
My question is the device in the photo. It is made by Honey Well and has enviracare written across it. Anyone familiar with it? Is a some type of electric percipitator?