Start with the problem you want solved
Start with the concern you are trying to address: visible dust, odors, humidity, ventilation or discomfort.
Salt Lake City: planning the visit
A detached house, apartment and mixed-use building can have very different heating arrangements. Tell the contractor which kind of property is involved, who controls the equipment and whether other occupants report the same symptom. For a rental, include the person who can authorize work and provide mechanical-room access.