Performed routine maintenance per energy savings agreement. Upon arriving to the air handler, the tech discovered the insulation from the door had come off. Tech reattached insulation as best as possible and used duct tape to secure, hopefully preventing any future air flow challenges. No other issues were found at todays visit. Technician also replaced customer provided dehumidifier filter. Dehumidifier and is working properly at this time and draining off properly as well. No other challenges were present at todays visit. System is heating properly and holding a delta t of 20+ degrees