Which furnace filter should YOU use? How long do they last? And when to change it!

[@MidwestMotor]

Do you need a lower Merv rating in the Summer to protect the AC or is it just the opposite - a lower Merv rating in the Winter? Does a "thicker," higher Merv rating hurt the AC or the Furnace more?

[@MetroHCI]

Depending on the size of equipment. We install 16x25x4 MERV11 & 20x25x4 MERV 11 filters on all new installs.

[@MidwestMotor]

@@MetroHCI Thanks. Just a typical residential unit for a 3,200 square foot house. Lenox unit with a 1-inch filter: 20x25x1. I read that too high a Merv will "clog," or choke the unit and static pressure drops and puts a strain on equipment leading to failure, etc and that residential with 1-inch should never use more than Merv 8. ?