Fifteen to twenty years with proper maintenance, which is meaningfully longer than a conventional central system. The catch is that mini splits need more frequent attention than most owners expect, and neglect shortens that lifespan considerably.

Why They Last Longer

Two reasons, both structural.

Inverter-driven compressors modulate output rather than cycling on and off at full power. Starting a compressor is the hardest moment in its operating life, and a system that ramps smoothly instead of slamming on several times an hour experiences far less mechanical stress.

Second, there is no ductwork to fight. A conventional system connected to undersized or leaking ducts works against static pressure for its entire life. A ductless mini split delivers air directly into the room with no distribution losses.

The Maintenance They Actually Need

This is where mini splits differ most from central systems, and where owners get caught out.

Filter cleaning, monthly. The indoor head has washable filters behind the front panel. They are easy to reach and easy to forget, and a loaded filter chokes airflow across the coil. Rinse them, let them dry fully, and put them back.

Professional indoor coil and blower service, annually. This is the item that matters most. The indoor coil sits wet whenever the unit is cooling, and the blower wheel — a narrow cross-flow drum — collects a film of dust that mixes with condensation.

Left alone, that becomes biological growth. The symptom is a musty smell when the unit starts, and it is an indoor air quality problem rather than only a performance one. Cleaning it properly requires partial disassembly and is not a homeowner task.

Condensate line clearing. Mini splits drain by gravity through a small line, and a clog means water running down your wall. This is one of the most common service calls on ductless systems.

Outdoor unit service, annually. Coil cleaning, refrigerant charge verification, and electrical testing.

Year-Round Operation Means More Hours

Every modern mini split is a heat pump — it cools in summer and heats in winter from the same equipment.

That means no off season. The compressor that runs through a seven-month Hill Country cooling season is the same one running in January, which is why twice-yearly service is the honest recommendation rather than annual.

The heating side has its own checks: reversing valve operation and the defrost cycle, neither of which a cooling-only inspection covers.

What Shortens Their Life

Dirty indoor coils and blower wheels, which is the most common and most preventable.

Refrigerant leaks. Line set connections are a known weak point, particularly on installations where the flares were not made carefully. Refrigerant is not consumed, so a system that is low has a leak, and running low destroys compressors.

Oversizing. An oversized mini split short-cycles, which defeats the inverter’s main advantage and leaves the room humid despite hitting the setpoint.

And poor installation generally — inadequate evacuation of the lines before charging leaves moisture in the system, which forms acid and shortens compressor life invisibly.

Multi-Zone Considerations

Systems with several indoor heads on one outdoor unit have more connections, more line set, and more that can leak.

They also need the outdoor capacity sized for realistic simultaneous demand rather than the sum of every head at maximum. Getting that wrong produces disappointing performance that gets blamed on the technology.

Keeping It on Schedule

Because mini splits ask so little day to day, service tends to slip. The unit keeps running while the coil gets progressively worse, and the first real symptom is a smell.

Both seasonal visits are covered under our Care Club maintenance plan, alongside your other cooling and heating equipment.

We serve Fredericksburg, Kerrville, Boerne, Comfort, and the surrounding Hill Country. Contact 72 Degrees or call (830) 468-5316.