Hey guys, I had a house with a centralized HVAC system before, and I want to know what kind of filter is normally installed in a typical residential air handler. I don't know what kind of make or model or even the type of HVAC unit it was for, only that I had one. Are they usually high MERVs like HEPA/ULPA? The fact that it never required or wasn't cleaned is leading me to think it was HEGA or a poorly maintained electrostatic precipitator. Pardon my absolute lack of knowledge with these things but if anyone can give me an answer from the little that I provided I'd very much appreciate it. God bless.