Preventive Maintenance Air Handlers - These air handlers provide air conditioning for a zoned VAV system. The air handler is an integral part of an air conditioner system. The air handler contains a blower, air filters, some coils (DX or chilled water), hot water coils (not all air handlers have heating coils in them), and some controls.

Preventive Maintenance Air Handlers | York AHU’s

It is important to make sure all HVAC mechanical systems have regular scheduled preventive maintenance. Many commercial air handlers, such as these York air handlers, have filter racks in them which hold a bank of filters. These HVAC air filters protect the coils from clogging with dust and add some indoor air quality to the building. It is necessary to make sure these air filters are changed on a regular basis. Another item to look at is the blower. Large air handlers like this usually have bearings that need to be greased on a regular basis. These large blowers are also belt-driven and the belt should be changed on a regular basis.

Periodic Maintenance for Cleaning | Preventive Maintenance Air Handlers

Additionally, periodic cleaning of the air handler should be scheduled to clean the coils and interior spaces of the air handler to maintain a clean system. Typically, this can be set up on a weekend or off time when the building has the least amount of occupants. Coil cleaner is commonly used and sometimes the coil cleaner can be overwhelming for some occupants.

Therefore, setting up a periodic cleaning on a weekend or holiday is warranted to avoid issues for the odors of cleaning fluids to clean the air handling unit. During this time, scheduled replacement of bearings and other moving parts can be and will reduce downtime during the year. Scheduling this can save in energy cost also as a clean coil reduces friction and allows better airflow so the system will work more efficiently.

Basic Air Handler Maintenance Checklist (Commercial Air Handlers) | Preventive Maintenance Air Handlers

• Check and change air filters.
• Check and change belts
• Check sheaves for proper adjustment and wear
• Check alignment of the shaft
• Grease bearings
• Check and clean blades on the blower
• Check condensation drain for clogs. Make sure the pan is not rusted through and holds and drains water without leaking into the air handler.
• Check for refrigerant leaks in valves, coils, and piping for direct expansion systems.
• Check actuators for proper operation for hydronic systems
• Check freeze stats for proper setting and function.
• Check all dampers for proper operation for given setpoints.
• Check electrical connections for tightness
• Check to make sure there are no unusual vibrations
• Check to make sure all fitting, nuts, and bolts are tight

Basic Air Handler Maintenance Checklist (Residential Air Handlers) | Preventive Maintenance Air Handlers

• Check and change air filters
• Check condensation drains to ensure they are draining properly. No algae or mold growth.
• Treat condensation pans with anti-algae tablets
• Check blower for proper rotation
• Check and clean blower and motor. Oil motor as necessary for motors that require oil
• Check coil for cleanliness and for leaks. Visual inspection is okay. Pay particular attention to capillary tubes to make sure they are not rubbing on anything.
• Check electrical connections for tightness.
• Check to make sure there are no unusual vibrations
• Check to make sure all mechanical brackets, nuts, bolts are tight.
• Check operation in the sequence of operation for proper functioning.

Basically, going over the unit to make sure everything is good and will not cause problems or a breakdown in the near future. For commercial air handlers, belts should be changed on a regular schedule to prevent breakdown. The same for residential except the belts as most residential air handlers are direct drive blowers while blowers are belt driven for most commercial systems. Air handler maintenance is a basic check over the system for proper functioning and to make sure no apparent problems visually appear or appear with any diagnostic tools. Periodic maintenance is always recommended on electrical and mechanical devices and is akin to doing a basic tune-up or oil change on a vehicle.

York Air Handlers – Preventive Maintenance Air Handlers

Resource: The Fundamentals of HVAC Direct Digital Control