The most important maintenance task to ensure the efficiency of your air conditioner is to replace or routinely clean your filters. Dirty, clogged filters can reduce the amount of air flow and significantly decrease system efficiency. When air flow is obstructed, dirt can bypass the filter and deposit directly on the evaporator coil, which impairs the heat absorption capacity. Replacing a dirty filter with a clean one can reduce energy consumption by 5% to 15%.
Look for the minimum filter efficiency value, or MERV, which ranges from 1 to 12 for domestic air conditioning units; the higher the number, the better the filtration. Federal laws require air conditioning units to be much more efficient than they were 10 years ago. For central air conditioning, look for the seasonal energy efficiency index, or SEER; for window units, the measurement is simply called the energy efficiency index, or EER. The standards require a SEER of 13 and an EER of 8, but devices with higher numbers will cost less to operate.
Your air conditioner unit will eventually break, even if you follow an air conditioner maintenance checklist perfectly. The replacement filter must be a copy identical to the old one. If a filter of another size or shape is installed, it could allow hair and debris to pass into the air conditioning unit. Cleaning the air conditioner in spring before putting it into operation will help it work better during hot summer days.
When your air conditioner needs more than regular maintenance, for example, when it doesn't reduce the indoor temperature to a comfortable level, hire a professional service technician. Anywhere you notice smoke moving away from something or being sucked into something, it's likely that there's an air leak. Ducts can lose up to 30 percent of airflow due to leaks, and window air conditioning units are notoriously difficult to seal properly. There are a number of ongoing maintenance and upgrades to your duct system that can improve duct performance.
The air compressor and condenser in a central air conditioning system are usually located outside the house, near the foundation. The evaporator coil and the air conditioner condenser coil accumulate dirt over time. Unless you're going on vacation, don't turn off the system; otherwise, the air compressor will have to work harder to cool the house later on. Replacing the air filter can reduce energy consumption of the air conditioner by 5% to 15%, saving you money on electricity bills.
Consider running the air conditioner along with floor or ceiling fans to help cool air circulate more effectively. When you sign a maintenance contract, you're also likely to receive discounts on repairs and new equipment.