It should not. Your air conditioner is a sealed system, and refrigerant does not get used up. If someone has added it two summers in a row, something is letting it out.

If your AC needs refrigerant every year, the refrigerant is not the problem. A leak somewhere in a sealed system is. Adding more each summer treats the symptom and leaves the cause exactly where it was.

We would rather find your leak once than sell you refrigerant every summer. Ask any technician to show you where it is going, including ours. Below we cover how your system actually works, why leaks turn up more often in Houston, and what repeated top-offs cost you.

It should not. An air conditioner is a sealed system, and refrigerant is not used up the way fuel or oil is. It circulates in a closed loop, absorbing heat inside and releasing it outside, over and over.

If your system is low, refrigerant escaped. That means a leak somewhere in the coils, the joints, or the line set. Refrigerant is federally regulated, and only certified technicians can buy it or handle it.

Adding more without finding the leak is a temporary fix. The new refrigerant leaves the same way the last batch did.

Common leak points:

• The evaporator coil in your attic unit
• Brazed joints and fittings
• The line set running between indoor and outdoor units

A leak search should come before any refrigerant is added.

Your air conditioner does not make cold air. It moves heat out of your house and dumps it outside. Refrigerant is what carries the heat on that trip.

It works by changing state. Inside your home, refrigerant passes through the evaporator coil as a cold low-pressure liquid. Warm air blows across that coil, the refrigerant absorbs the heat, and it boils into a gas.

That gas travels outside to the condenser. There it gets compressed, releases the heat it picked up, and turns back into a liquid. Then it heads indoors and starts over.

The whole path is sealed copper. Coils on both ends, a line set between them, and joints where the pieces meet. Nothing in that loop opens to the outside air.

Nothing in that process consumes refrigerant either. It changes form constantly, but the amount never drops. The charge your system was given at installation should still be in it today.

Low means escaped. It never means used up. Somewhere in that sealed loop, refrigerant found a way out.

Leaks come in every size. A pinhole in a coil releases refrigerant slowly enough that you may not notice for a season. A failed joint empties a system in days.

Watch for these:

• Cooling that has weakened over time without an obvious cause
• Run times that keep getting longer
• Ice forming on the refrigerant lines or the indoor coil
• Hissing or bubbling near the lines
• Warm air from the vents while the system runs

The ice one gets misread constantly. People see frost and assume the system is working hard. It usually means the opposite. Too little refrigerant drops the coil below freezing, and moisture in the air freezes onto it.

Running undercharged is hard on the equipment. The compressor works against conditions it was never designed for, and it is the most expensive part in the system.

Leaks happen everywhere. They show up more often here, and the reasons come down to how our homes are built and how long we run the equipment.

Houston homes sit on slabs. There is no basement, so the evaporator coil almost always ends up in the attic. That coil spends every summer in a space far hotter than the air outside.

Metal responds to that. It expands in the heat and contracts as things cool, over and over, season after season. Joints and connections carry that stress for years before anything shows.

Run time adds to it. Our cooling season lasts about seven months, so the system cycles far more here than it would in a milder climate. Every cycle sends vibration through the same fittings.

Humidity contributes as well. Coil surfaces stay damp for long stretches in our climate, and that moisture works against the metal over time.

Most of the leaks we find in Houston are on evaporator coils that have spent ten summers in a hot attic.

None of this makes a leak normal. It means finding them early matters more here than it does most places.

An attic that runs cooler is easier on everything in it. Look at attic insulation and ventilation.

A yearly top-off feels like maintenance. It is closer to filling a tire with a nail in it.

Here is what happens while the leak stays open:

• You pay for refrigerant again every season, and the leak keeps its schedule
• Your system runs undercharged between visits, which strains the compressor
• Undercharged operation uses more energy for less cooling, all season long
• Refrigerant escaping into the air is a regulated matter, not just a household one

The pattern also speeds up. Leaks widen as the metal around them keeps flexing and corroding. What started as a top-off every other summer becomes every summer, then mid-season.

The end of that road is not another refrigerant charge. It is the compressor, which is the part all of this was quietly wearing down the whole time.