Mini-split air conditioners, which do not make use of ducts and instead are installed within individual rooms of your homes, can still eventually wear ]down over time. If your system has failed, you will likely need a complete replacement, but being able to identify mechanical issues with your mini-split air conditioner can, in some cases, allow you to have your existing repaired instead, saving you both time and money.
One very obvious sign that your mini-split air conditioner needs to be replaced is that there is heavy condensation either on the unit or in the area immediately underneath. A properly functioning unit will not generate a great deal of condensation, and the condensation that does accumulate will be drained out of the unit without damaging the surrounding area. Heavy accumulation can come when you've been running the unit for too long, when the condensate drain line is clogged, when there has been a refrigerant leak, and in many other situations, so you'll want a professional to inspect the system and determine whether repair or replacement is the best course of action.
The air that comes out of your mini-split air conditioner should not carry an odor with it. The presence of any sort of smell in the cool air created by your unit points to an underlying problem. An earthy smell can indicate that mold has begun to grow within your unit, which can represent a fairly serious health hazard and can contribute to respiratory illnesses and conditions. On the other hand, the smell of burning points to an electrical issue, which means that you should avoid running your unit at all, as it is at risk of damaging its internal components. Finally, a strong chemical that makes you feel light-headed or dizzy can indicate that your unit is leaking refrigerant, which is a hazardous material and will eventually render your air conditioner completely unable to generate cold air. All of these smells indicate serious problems that require unit replacement or extensive repairs.
Your ductless mini-split air conditioner should operate almost silently with only the sound of blowing air characterizing its operation. Grinding, banging, or hissing can indicate that there is a mechanical issue, which will likely only grow worse if you continue to operate your unit and may result in more expensive and extensive repairs as a result.
If you begin to see signs of these issues with your mini-split unit, locate the nearest AC repair services in your area.