This is an older home that has a second story. One heating and air system does the whole home with a part of the supply ductwork feeding upstairs into the attic to do the top floor. It was even updated later and turned into zoning so that there would be a thermostatic controller upstairs, but It never had a return added. It constantly struggled with airflow issues and uneven temperatures. It often made the downstairs colder than was desired, and the system’s static pressure was very high.

Today I added the much-needed return it never had. By the end of the day, the temperatures had stopped fluctuating and the downstairs was comfortable for the homeowner. I installed two returns for each bedroom upstairs, and a wireless indoor temperature sensor.