Mini-split air conditioning systems are more self-contained than central air conditioners, and so they tend to have fewer problems and be somewhat easier to service. However, they share many design characteristics with other AC systems, so you shouldn't expect them to remain trouble-free forever. Refrigerant leaks are one common source of problems with any air conditioning unit.
Why Do Refrigerant Leaks Matter?
Typical residential air conditioners work by transporting heat from inside your home and dispersing it into the outside environment. The refrigerant cycle enables this behavior, and you can think of it as a transit system for heat. Cold liquid refrigerant travels through an evaporator coil in your house, absorbs heat, and then transports that heat to the outdoor condenser unit.
The heat exchange process relies on phase changes in the refrigerant. The refrigerant enters the evaporator coils as a cold liquid and leaves as a warm vapor. These state changes rely on proper pressure levels within the system. If the refrigerant pressure is too low, it can impact the system's performance, place additional strain on the compressor, and cause the evaporator coils to freeze.
How Do You Know If You Have a Refrigerant Leak?
You can usually find your evaporator unit in the basement when dealing with a traditional central air conditioning system. However, ductless systems keep the entire indoor side of the air conditioner in a single, self-contained unit. Since you typically install this unit within your living space, detecting problems before they become too severe can be somewhat more manageable.
A hissing sound is one extremely noticeable symptom that's usually easier to detect on a mini-split unit. Recall that refrigerant leaves the evaporator as a warm vapor, so there may be a noticeable noise if the leak is close to the indoor unit. This sound will usually be most apparent immediately after the blower motor shuts off.
You should also pay close attention to changes in temperature or humidity from the vents. Your AC should blow air that's about 20 degrees cooler than ambient temperature. Colder air can indicate low refrigerant pressure or a frozen evaporator coil. Likewise, high humidity is another sign that your system's pressure is no longer within standard operating specifications.
What Should You Do?
Refrigerant can be potentially hazardous to your health, but most leaks will not expose you to sufficient quantities to cause harm. However, low pressure can be incredibly harmful to your air conditioner. When system pressure falls too low, your compressor will struggle to maintain the refrigerant cycle, placing added wear on this extremely costly component.
If you think you have a refrigerant leak, it's a good idea to contact an HVAC professional as soon as you can. Resolving the problem will not only keep your mini-split system operating at peak efficiency, but it will also ensure that you don't suffer an expensive premature failure. Contact an air conditioning repair service for more information.