Winter Maintenance Checklist for Commercial Air Conditioning Systems

A well-maintained commercial air conditioning system operates more efficiently year-round, helping businesses save on energy costs and preventing unexpected breakdowns in any season.

With cold days ahead in the southern hemisphere, it is an excellent time to get some maintenance done on these systems so that they can seamlessly shift their climate control capacity from cool in summer to warm in winter.

In this article, we have compiled a comprehensive maintenance checklist to ensure your commercial air conditioning systems remain in top shape for the changing seasons.

1. Inspect and Clean Air Filters

Air filters play a crucial role in maintaining indoor air quality and ensuring the efficient operation of commercial air conditioning systems, especially during the colder months.

With people spending more time indoors and wearing thicker clothes with more fibres, filters can get dirty or clogged more easily. This can restrict airflow and cause the system to work harder, thus consuming more energy.

Maintenance Checklist:

• Inspect Monthly: Check the air filters monthly during winter, especially if the system is still being used for heating. It is best to replace them at least every three months; however, filters in dusty areas or high-traffic environments may need more frequent replacement.
• Clean or Dispose: Remove the air filters, inspect them for dirt and debris, and clean them if reusable. Replace disposable filters to avoid airflow restrictions.
• Restock: Keep a stock of replacement air filters on hand to ensure timely replacements regardless of the season.

Consider using high-efficiency particulate air (HEPA) filters to capture finer particles and improve air quality. It provides a healthier indoor environment for occupants, especially during winter when flu season is at its peak and people tend to be inside more often.

2. Check and Clean Evaporator and Condenser Coils

Even in winter, dust and grime can accumulate on evaporator and condenser coils, reducing a commercial air conditioning system’s efficiency by up to 30% and leading to higher energy consumption. Regular cleaning of the coils ensures optimal heat exchange, which is essential for heating in winter.

Maintenance Checklist:

• Evaporator Coils: These are typically located inside the air handling unit. It is best to engage a professional technician for a more thorough cleaning to ensure safety. Typically, they will use a soft brush or vacuum to remove dust and debris.
• Condenser Coils: These can be found in the outdoor unit. Clear any debris, such as leaves or twigs. Use a garden hose to wash off dirt and grime, especially after strong winds and storms.

3. Inspect and Seal Ductwork

Leaky ductwork can result in significant energy loss and reduced efficiency in an air conditioning system, particularly if it is used for heating during winter. Properly sealed ducts ensure that heated air reaches its intended destination and raises the ambient temperature more quickly with less effort.

Maintenance Checklist:

• Ductwork Inspection: Check the air conditioning system’s ducts for visible signs of wear, such as holes, tears, or loose connections. Pay attention to areas exposed to extreme temperatures, such as roofs or external walls.
• Ductwork Sealing: If necessary, you can engage professional technicians to seal any leaks. Mastic sealant or metal tape tend to be the tape of choice for this as standard duct tape can deteriorate over time. They will also ensure all connections are secure and insulated where necessary, especially in unconditioned spaces like attics or basements.

4. Test Thermostat Calibration and Operation

Accurate thermostats ensure that commercial air conditioning systems maintain the desired indoor temperature efficiently, particularly in the cooler winter months. A poorly calibrated thermostat can lead to improper temperature regulation, increasing energy consumption.

Maintenance Checklist:

• Test the Calibration: Verify the thermostat’s accuracy by comparing its reading with a reliable room thermometer. Adjust the settings if necessary to ensure accurate temperature control.
• Test the Operation: Test the thermostat’s responsiveness by setting it to various temperatures and observing the commercial air conditioning system’s cycling. Programmable thermostats should be adjusted to optimise energy savings during off-peak hours.

5. Inspect Electrical Components and Connections

Faulty electrical connections can cause commercial air conditioning system failures and pose safety hazards to the occupants of the building. Electrical issues are one of the leading causes of Heating, Ventilation, and Air Conditioning (HVAC) system failures and can significantly increase repair costs if not addressed.

Maintenance Checklist:

• Get Professional Help: For safety purposes, it is vital not to attempt any repairs on your own. Even inspection can be dangerous, so have a qualified commercial air conditioning technician perform any inspections and repairs needed instead. They can also test voltage and amperage to ensure components are operating within safe parameters.

6. Lubricate Moving Parts

Proper lubrication of the moving parts of a commercial air conditioning system reduces friction, preventing wear and tear and ensuring smooth operation during the colder months. A lack of lubrication can lead to overheating and failure of critical components like motors and bearings.

Maintenance Checklist:

• Check the Components: Before applying the lubricant, inspect the motors, bearings, and fans for any wear and tear. These parts experience significant motion and friction in a commercial air conditioning system.
• Lubricate as Recommended: Use the manufacturer-recommended lubricant for the commercial air conditioning systems. Over-lubrication can be as detrimental as under-lubrication, so follow guidelines precisely or engage a professional technician to do so.

7. Check Refrigerant Levels

Ensuring that refrigerant levels are maintained at proper levels enables the air conditioning system to stay effective and helps identify any leaks early. This is important as an undercharged system can lead to inefficient heating, which is particularly noticeable in cold winter months and can result in higher energy costs, as well as potential damage to the compressor.

Maintenance Checklist:

• Professional Inspection: Have a licensed commercial air conditioning technician check the refrigerant levels and inspect for leaks. Leaks should be repaired immediately to prevent further loss of refrigerant.
• Refrigerant Recharge: If refrigerant levels are low, the technician should be able to recharge the commercial air conditioning system to the manufacturer’s specifications. Ensure that they check the system’s superheat and subcooling readings to confirm proper charge.

8. Clean and Clear Condensate Drain Lines

Blocked condensate drain lines of air conditioning systems can cause water damage and increase humidity levels, affecting indoor air quality in commercial buildings. Overflows can also lead to mould growth and structural damage.

Maintenance Checklist:

• Inspect Condensate Drain Lines: Check for any signs of mould or algae growth and clean as necessary.
• Clean Condensate Drain Lines: Use a bleach and water mixture to clean the drain lines. Flush them out to remove any blockages. Commercial drain cleaning solutions are also effective. Experienced technicians can perform the cleaning for you and also install a float switch to shut off the system if the drain line backs up, preventing overflow damage.

9. Inspect Insulation on Refrigerant Lines

Proper insulation prevents energy loss and ensures the commercial air conditioning system operates efficiently. Insulated lines reduce the risk of refrigerant temperature fluctuations, which can impact cooling or heating performance.

Maintenance Checklist:

• Visual Inspection: Check the insulation on refrigerant lines for any damage or wear. Look for signs of degradation, such as cracking or peeling.
• Replacement: Replace any damaged insulation to maintain commercial air conditioning system efficiency. Use foam insulation specifically designed for refrigerant lines and secure it with appropriate tape.

10. Schedule a Professional Maintenance Check

Regular professional inspections can identify and address issues overlooked during routine checks. Professional maintenance can extend the system’s lifespan, improve efficiency, and ensure compliance with warranty requirements.

Maintenance Checklist:

• Maintenance Frequency: Schedule a comprehensive maintenance check by a certified HVAC technician at least twice a year. Ideally, once before winter and once before summer.
• Detailed Tasks: The technician will perform a thorough inspection, cleaning, and tuning of the entire system, ensuring all components are in optimal condition. This includes checking refrigerant levels, inspecting electrical connections, calibrating thermostats, and verifying system performance.

Protect Your Investment in Air Conditioning with Professional Care

Winter maintenance for commercial air conditioning systems is not just about preparing for efficient heating in the colder months but ensuring the systems are ready for peak cooling performance even when the weather turns warm. By following this checklist, businesses can ensure their air conditioning systems remain efficient, reliable, and cost-effective year-round.

It is important to invest in regular professional commercial air conditioning maintenance. This helps to identify potential issues early, reduce downtime, and extend the lifespan of the equipment. Ultimately, it saves businesses significant costs and headaches in the long run.