Start with the problem you want solved
Start with the concern you are trying to address: visible dust, odors, humidity, ventilation or discomfort.
Herriman: planning the visit
A finished basement or newly occupied room changes the questions to ask about comfort. Explain the new use, current supply and return locations and whether the thermostat represents the problem room. Request a proposal that considers distribution and controls, not a replacement based only on the old equipment label.
