HVAC unit illustrationAs summer temperatures rise, so do electric bills. Follow these steps to test the efficiency of your HVAC unit.

The outdoor temperature should be above 80 degrees, and you should set your thermostat well below the room temperature to ensure the system runs long enough for this test.

  1. Using a digital probe thermometer (about $12), measure the temperature of the air being pulled into your HVAC filter.
  2. Measure the temperature of the air blowing out of your A/C vent.
  3. Subtract the A/C vent temperature from the HVAC filter temperature. You should see a difference of about 17 to 20 degrees. If the difference is less than 17 degrees, you may need a licensed technician to check the coolant. If the difference is greater than 20 degrees, your ductwork may need to be inspected for airflow restrictions.