High cooling efficiency is one of the many advantages of mini-split air conditioning systems. These systems can cool your home without relying on ductwork, drastically reducing their potential for losing conditioned air. Since mini-splits can be so energy-efficient, it's usually noticeable when they start drawing more energy than usual.
If your summertime AC bills are on the rise, it may be time to start looking at your AC unit for potential causes. Keep these three repairs in mind if you're looking for the reason your system is suddenly draining your wallet.
1. Refrigerant Problems
All air conditioning systems rely on an adequate refrigerant charge to transport heat. An overcharged or undercharged system can significantly impact efficiency and even reduce the lifespan of critical system components. While large refrigerant leaks will quickly cause your system to stop working, small ones may go unnoticed for some time.
What To Look For: While refrigerant does have an odor, many leaks are not severe enough to produce detectable sounds or smells. Instead, pay attention to the signs of a frozen evaporator. Common symptoms include increased interior humidity and short cycling. Your AC may also produce warmer air since the ice on the evaporator coils acts as insulation.
2. Damaged Condenser Coils
Your mini-split system consists of the indoor (or low-pressure) and outdoor (or high-pressure) sides. The condenser coils are a critical part of the high side of your system. These coils release heat back into the atmosphere after the compressor turns it into a hot, high-pressure gas. Condenser coil issues can prevent your refrigerant from releasing heat, reducing overall system efficiency.
What To Look For: Condenser coil problems will produce similar symptoms to refrigerant issues since they affect the refrigerant cycle. If you suspect a condenser coil issue, you can perform a visual inspection. Look for build-ups of dirt or debris on your outdoor unit and note any bent or damaged fins. An HVAC tech can repair a damaged coil without replacing the entire unit in many cases.
3. Thermostat Failure
Although mini-splits use a single integrated head unit, they still include a built-in thermostat that determines when to provide cooling. Thermostat problems can drastically reduce efficiency by causing the system to wait too long to come on or run for longer than necessary.
What To Look For: Your mini-split system should kick on reliably when the temperature creeps above your thermostat setpoint. If you turn down the thermostat and the system doesn't come on relatively quickly, that's a good indication of a thermostat issue. Likewise, you may notice your system running even though the room temperature is already much colder than desired.
Contact a local AC repair technician to learn more.