When it comes to air conditioning, a good preventative maintenance program will increase operating time and save money by identifying concerns before they become problems. Once the hot weather arrives, implementing planned maintenance allows you to schedule repairs instead of reacting to sudden unexpected issues. A/C filters, coils, and fins require regular maintenance to ensure optimum performance and neglecting necessary maintenance results in a steady decline in performance and increased energy use.
Clogged, dirty filters restrict airflow and reduce a system’s efficiency. When airflow is restricted, the air that bypasses the filter will carry dirt directly into the evaporator coil and reduce the coil’s heat-absorbing abilities. To ensure efficiency, routinely clean or replace filters.
The condenser and evaporator coils collect dirt over time but a clean filter helps to keep the evaporator performing well. Debris reduces air flow, insulates the coil and reduces its ability to absorb heat. Being exposed to the elements, it is easy to see the dirt collecting on the fins. Cleaning the coil fins and removing any debris around the coil will ensure optimal performance.
The aluminum fins on evaporator and condenser coils are easily bent and can block airflow through the coil. Air conditioning wholesalers sell a tool called a “fin comb” that will comb these fins back into their original condition.Remember to always use caution when performing preventative system maintenance, as ambient conditions (heat load) will increase refrigerant hose temperatures and don’t forget, having the right quality parts on hand makes all the difference.
See How To and Which Components to Inspect and watch this video to learn more about Basic A/C Troubleshooting.
Heavy-duty A/C system components rarely fail. In fact, the system fails the components because of contaminated refrigerant oil and general lack of preventive maintenance.
Tech Tips From RedDot
One of the best ways to improve uptime and reduce maintenance costs for the customer is to promote a basic visual check of major A/C components, hose connections, and fittings at regular intervals, like with every engine-oil change. This inspection routine has another benefit: it can generate business for your parts and service department.
Many A/C components are consumable items. It’s more cost-effective to replace them than to repair them. So preventive maintenance is an opportunity to sell a range of OEM-quality all-makes replacement parts for the air conditioner. Here are some examples:
1. RECEIVER DRIERS
The receiver-drier’s moisture indicator provides a quick visual cue about the refrigerant’s condition: a blue dot means the refrigerant is dry; pink, white, or grey indicates acid or moisture in the system. Checking the sight glass during an oil change or any scheduled maintenance procedure means the truck can receive necessary service while it’s there in the shop, before moisture and acid damage critical A/C components and lead to a failure on the road.
Dust, bugs, feathers, and other debris collect on the face of fins and tubes and act as a thermal barrier, making it hard for the condenser to shed heat. Condensers also fail because of vibration, which can cause hose connections to come loose and fatigue the condenser tubing adjacent to the fittings. Every 12 months, the condenser should be cleaned (taking special care not to bend or damage the fins) and the hose connections securely clamped.
3. COMPRESSOR/CLUTCH ASSEMBLY
The compressor provides the mechanical energy to circulate refrigerant and manipulate the pressure inside the system. It’s the heart of the A/C system, and the No. 1 HVAC maintenance expense item. Excessive noise and poor cooling performance are the two most obvious symptoms that a compressor is failing. Replacing the compressor involves pulling down the system, which adds refrigerant recovery and recharge to the repair cost.
Next time you see, “A/C won’t blow cold air” on a work order, note that the repair and downtime probably could have been avoided with a simple visual inspection of the truck’s air conditioning system. Any time you change the truck’s oil, check the A/C.