A Complete Guide to Commercial HVAC Winter Maintenance

Replacing air filters is one of the most important maintenance tasks. Clogged, dirty filters restrict airflow and make the system work harder to keep interior spaces heated or cooled. Facility managers should change filters every one to three months, adjusting the schedule based on filter inspections. Disposable pleated filters are common in commercial units. Electrostatic and MERV 13 filters offer deeper trapping of allergens and pollutants. Filters should fit snugly within slots to prevent air from leaking around edges.

Leaky ductwork results in huge energy loss as conditioned air escapes before reaching interior zones. Use a specialized duct sealing mastic compound to seal joints, seams, connections, and any cracks or gaps evident during a visual inspection. Insulate any new or replaced duct sections to specification. Perform duct pressure tests annually to check for leaks and seal any problem areas. Keep ductwork clean by removing accumulated dust and debris as needed.

An accurate thermostat is critical for maintaining the right temperature during occupied hours while conserving energy during vacant periods. Make sure the thermostat is properly calibrated and adjust as needed. Set programmed temperature setpoints and schedules to match operating hours. A setback of 5–10°F when closed can yield significant cost savings. Smart Wi-Fi thermostats allow remote monitoring and adjustment via mobile apps.

Dirty evaporator coils reduce the cooling efficiency of AC systems and can lead to premature component failure. Facility managers should inspect the coil annually and clean it if substantial dust and debris is present. Use a soft brush and vacuum to remove loose buildup. For tougher buildup, a commercial coil cleaner may be required. Severely damaged or corroded coils should be replaced.

It’s important to inspect furnaces before the heating season causes issues. Technicians check the electrical components, inspect the heat exchanger for cracks, test and adjust the pressure switch, clean burner ports, check the pilot light or ignitor, and confirm the blower fan is working properly. This ensures furnaces are operating correctly for winter comfort and safety.