Map the building
List room use, envelope changes, comfort complaints, distribution, equipment, fuel, electrical service, exhausts, and ventilation.
Measure before selecting
Load, airflow, static pressure, water temperatures, radiation, ducts, and operating data help distinguish capacity from distribution problems.
Plan both seasons
Cold-climate heating, summer humidity, shoulder-season control, condensate, freeze protection, and backup operation belong together.
Compare scopes, not boxes
Ask about load basis, distribution, electrical, venting, line routes, drainage, controls, permits, commissioning, and warranties.