Chattanooga Home Inspection: AC and Heat Pump Terms

The heating and cooling section of an inspection report is often one of the longest. Around Chattanooga, notes about crawl space ducts, humidity and heat pumps come up again and again. These short explanations help you understand what a note usually means. Your inspector saw the system in person, so rely on their findings and ask them about anything unclear.

Cooling performance

Temperature differential — The difference between return air and supply air. A low reading can mean low refrigerant, a dirty coil or poor airflow.

Short cycling — The system turns on and off quickly. Common with oversized equipment and bad for humidity control.

Not tested due to outdoor temperature — Inspectors often can't run cooling on cold days or heat pump heating on hot days. It isn't a defect, but it leaves a gap.

Heat pump notes

Auxiliary heat / emergency heat — Backup electric heat or a furnace that helps on the coldest days.

Reversing valve — Switches the heat pump between heating and cooling.

Dual fuel — A heat pump paired with a gas furnace that takes over in colder weather.

Crawl space and ducts

Disconnected / damaged duct in crawl space — A loose or torn duct blowing air under the house. See ductwork and airflow.

Condensation on ducts — Sweating ducts in a humid crawl space, often from missing insulation.

Moisture / missing vapor barrier — Damp soil exposed under the house. See crawl space humidity.

Drainage and age

Condensate line / float switch — The drain that carries water from the coil and the safety switch that stops the system if it backs up.

Manufacture date — Read from the data plate. See repair or replace your AC.

How serious is it?

• Monitor: dirty filter, minor rust, plants close to the unit.
• Fix soon: crawl space duct problems, missing vapor barrier, weak temperature split.
• Before closing: no cooling or heat, water damage, a system that won't run.

For inspectors and agents

You're welcome to link this page for clients. Related: hiring an HVAC contractor in Tennessee · AC replacement · furnace repair