Why AC Maintenance is Critical to Sustainability

PART 1

 Heating ventilation and air conditioning (HVAC) systems account for up to 50% of a commercial installations energy use and dominate peak electricity demand. 

 Capital and maintenance costs for these systems also comprise a high portion of overall building costs. Improving HVAC efficiency can therefore have a big impact on your bottom line by reducing energy use, maintenance costs and peak demand charges. It also brings reputational benefits through higher energy efficiency ratings, such as NABERS.

A holistic HVAC strategy relies on an integrated approach to:

• reduce demand
• optimise existing systems
• upgrade to more efficient systems.

 Reduced Energy Demand through Maintenance

 An air conditioner's filters, coils, and fins require regular maintenance for the unit to function effectively and efficiently throughout its years of service. Neglecting necessary maintenance ensures a steady decline in air conditioning performance while energy use steadily increases.

 Filters

The most important maintenance task that will ensure the efficiency of your air conditioner is to routinely replace or clean its filters. Clogged, dirty filters reduce the amount of airflow and significantly reduce a system's efficiency. In addition, when airflow is obstructed, air can bypass the filter and deposit dirt directly into the evaporator coil and impair the coil's heat-absorbing capacity. Replacing a dirty, clogged filter with a clean one can lower your air conditioner's energy consumption between 5% to 15%.

For central air conditioners, filters are generally located somewhere along the return duct's length. Common filter locations are in walls, ceilings, or in the air conditioner itself. Room air conditioners have a filter mounted in the grill that faces into the room.

Some types of filters are reusable; others must be replaced. They are available in a variety of types and efficiencies. Clean or replace your air conditioning system's filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or you have fur-bearing pets in the house.

Coils

The air conditioner's evaporator coil and condenser coil collect dirt over their months and years of service. A clean filter prevents the evaporator coil from soiling quickly. In time, however, the evaporator coil will still collect dirt. This dirt reduces airflow and insulates the coil, reducing its ability to absorb heat. To avoid this problem, check your evaporator coil regularly and clean as necessary.

Outdoor condenser coils can also become very dirty if the outdoor environment is dusty or if there is foliage nearby. You can easily see the condenser coil and notice if dirt is collecting on its fins. Dirt and debris should be minimised near the condenser unit, falling leaves, lawn mower clippings and mulch are all potential sources of dirt and debris. Cleaning the area around the coil, removing any debris, and trimming foliage back at least 2 feet (0.6 meters) allow for adequate airflow around the condenser. The aluminium fins on evaporator and condenser coils are easily bent and can block airflow through the coil, these require combing to straighten the fins and allow the air flow to circulate.

Condensate Drains

 Regularly pass a stiff wire through the unit's drain channels. Clogged drain channels prevent a unit from reducing humidity, and the resulting excess moisture that may discolour walls or carpet and create unwanted constant water leaks.

Professional maintenance

When an air conditioner need maintenance, the technician should:

• Clean filters
• Check and clean drains and tundishes
• Check duct work in the vicinity of moisture producing items
• Check outlets for dirt and mould
• Check for correct amount of refrigerant
• Verify the correct electric control sequence and make sure that the heating system and cooling system operate
• Inspect electric terminals, clean and tighten connections, and apply a non-conductive coating if necessary
• Oil motors and check belts for tightness and wear
• Check the accuracy of the thermostat.

I find it common for businesses not to have a regular maintenance program in place for HVAC assets. With sustainability and cost savings in mind, it is now a wise investment .