About Air Filters; Which Vent Do I Need to Change Filter?
I am confused about which vent, register, or in-take do I need to change filters. I remember seeing people changing filters on the air-out and in-take registers, while the A/C or heater were not installed with the filters. A/C technicians always just change the filter at the big unit in the attic. Is it just sufficient to change the filter in the attic?