What do you check on heating and cooling systems?

We operate the heating and cooling systems with normal controls and inspect the visible equipment, ductwork, condensate drainage, and venting. For every unit we measure return and supply air temperatures and record the difference, often called the temperature split. A cooling split better than 15°F is generally considered acceptable, and Dragonfly typically likes to see 18°F to 22°F. What’s acceptable depends on the age and type of system, so our inspectors use years of field experience to judge each one. Below about 18°F, we may still recommend service by a qualified HVAC contractor. Heating splits in our recent reports ran about 27°F to 40°F. We also read equipment age and refrigerant type from the data plates. Typical findings include rust or mineral deposits in the drain pan, water in the secondary drain (often a clogged primary line) and condensate lines missing insulation in the attic. Maintenance history and remaining life are best confirmed with an HVAC contractor.