Proper go back filter sizing reduces static pressure, improves power efficiency

https://privatebin.net/?48df7308273a46c6#7pBA78D5AhfZ9omFokretVLZKDjYMfzfE4kUWVkqYfSY

Proper return filter out sizing reduces static stress, improves vigor performance, and protects the furnace from airborne dirt and dust and debris accumulation.