I’ve spent the better part of twenty years in South Texas attics, and if there is one thing I’ve learned, it’s that a brand-new air conditioner is only as good as the guy who held the torch on the day it was born. In San Antonio, homeowners often drop ten or fifteen thousand dollars on a high-SEER system, thinking they’ve bought a decade of peace of mind. But the reality is much uglier.
If the contractor you hire is more interested in getting to their next service call than checking your static pressure, you aren’t buying a cooling system; you’re buying a ticking time bomb. In a climate where the heat index hits triple digits for months on end, the precision of the setup determines whether that machine lasts fifteen years or five.
The Secret Saboteur: Your Existing Ductwork
The biggest mistake I see during a new
High static pressure is the silent killer of modern HVAC systems. It forces the blower motor to work at its absolute limit just to push air through restrictive, undersized pipes. Within a few seasons, the motor burns out, or the evaporator coil—starved for airflow—turns into a block of ice. A real
The "Tailgate Tech" and the Missing Micron Gauge
If you want to know if you’ve hired a pro or a "parts-changer," watch what happens after the copper lines are brazed together. In our humid San Antonio air, moisture is the absolute enemy of a refrigerant circuit. When those lines are open to the atmosphere, humidity gets inside. If that moisture isn't removed, it mixes with the refrigerant and oil to create a highly corrosive acid.
That acid eats the motor windings from the inside out. To prevent this, a tech must pull a deep vacuum using a digital micron gauge. If they just "purge" the lines or run a pump for twenty minutes without measuring the actual vacuum depth, they are leaving a chemical time bomb inside your walls. Precision in the charging process is just as critical. We don't "eyeball" it; we use sub-cooling and super-heat calculations to ensure the system is tuned to the exact ounce.
Why "Upsizing" is a Recipe for a Swampy Home
There’s a common myth in Texas that bigger is always better. Homeowners often ask me to go up a half-ton to "make sure the house stays extra cold." That is a disaster waiting to happen. An air conditioner’s primary job is to remove heat, but its secondary job—which is just as important in San Antonio—is to remove humidity.
An oversized unit will cool your house to 70 degrees in ten minutes and then shut off. Because it didn't run a full, long cycle, it never had the chance to pull the moisture out of the air. You end up with a house that is cold but "clammy." This leads to mold growth and a system that "short-cycles" itself to death. We use Manual J load calculations to look at your insulation, your windows, and which way your house faces to ensure the sizing is exact.
Redundancy: Protecting Your Ceiling from the Attic "Waterfall"
Finally, we have to talk about the water. A central air unit in San Antonio can pull ten gallons of water out of the air every day during a humid July. In most local homes, that unit is in the attic. If the primary drain line clogs—and in our heat, algae grows fast—that water has to go somewhere.
If your installer didn't install a secondary emergency pan or a float switch that kills the power when water is detected, you’re going to have a waterfall in your hallway. I’ve seen beautiful homes in Stone Oak and Alamo Heights ruined because of a $20 safety switch that was "too much trouble" to install. Accuracy and redundancy are what separate a professional installation from a disaster. Accuracy, transparency, and a bit of skepticism about "quick fixes" are the only ways to survive a San Antonio summer.
