Work Performed Responded to call regarding high humidity in the garage (furnace located in garage with loft apartment above). Inspected ductwork and confirmed that supply ducts had previously been open into the garage. No return air vents in garage. Supply ducts were slightly open, causing positive pressure in garage, no dehumidification is happening because air is not returning. Reviewed code requirements and furnace manufacturer’s manual: supply or return air openings into a garage are not permitted. Discussed findings with client. Client has since sealed all garage supply air vents to bring the system into code compliance. Recommended and confirmed client’s plan to place a dehumidifier in the garage to address humidity issues independently. Or install an air exchange system in garage. Advised furnace needs to be heated in winter because it is high efficient and cannot freeze. Performed full maintenance on both high-efficiency furnaces (garage/loft unit and house unit). Results Fur