We performing repair service diagnostics today on a Lennox Air Conditioner AC unit. Checked charge, 77° outside air temp and pressures were off a little bit at first. The air filter was installed backwards. The after adjusting the air filter, the Air Conditioner A/C charge and pressures looked good. The duct air temp dropped by the recommended 20°.
Pro Tip: To get proper airflow in your HVAC system, you should always have the filter’s arrow pointed towards the indoor unit. Always change your 1″ thick filter once a month and never use any filters higher than a MERV 10 level to get the required proper airflow. High MERV rated filters are designed to catch large and small particles. Since it can catch the smaller particles, the opening is also smaller and will get dirty quickly. Additional, 1″ filters are thin and will quickly fill up with particles blocking airflow.