How Houston's June Heat Cracks AC Refrigerant Lines at Home

June in Houston is brutal. By the time we hit mid-month, outdoor temps are pushing 95°F or higher, and your AC system is running almost around the clock. Most people focus on the filter or the thermostat. But one of the most expensive things I see during summer inspections is refrigerant line damage — and it's almost always been sitting there quietly for months before anyone notices.

Here's the basic setup. Your AC system has two refrigerant lines running between the outdoor condenser and the indoor air handler or evaporator coil. The larger one is the suction line, wrapped in foam insulation. The smaller one is the liquid line. Both are copper, and both take a beating when summer hits.

The foam insulation on the suction line is your first line of defense against heat gain. When it's intact, it keeps the cold refrigerant from picking up heat before it reaches the coil. But that foam degrades. Sun exposure breaks it down, especially where the line exits the house or runs along an exterior wall. Once the foam cracks open or falls off — which I see constantly in Pearland, Friendswood, and the League City area — the suction line sweats, absorbs ambient heat, and the system has to work harder to cool the same space. Your electric bill climbs. Your comfort drops.

That's the minor version of the problem. The bigger issue is refrigerant leaks. A hairline crack or a loose flare fitting on a copper line can bleed refrigerant slowly over weeks. The system runs but never quite cools right. I'll often see ice buildup on the evaporator coil indoors — that's actually a sign of low refrigerant, not a sign things are working well. Ice on an indoor coil in June means the system is starving for refrigerant and the coil temperature is dropping below freezing.

During an inspection I check the suction line insulation condition, look for oil staining around fittings (a telltale sign of a refrigerant leak), and note whether the disconnect box at the outdoor unit is properly rated and accessible. TREC standards require me to operate the system if outdoor temps are at or above 65°F — and in June that's never a question. I run it, give it time to stabilize, and check the temperature differential between supply and return air. A properly functioning system should show roughly a 16°F to 22°F split. If I'm seeing less than that, something's off — and refrigerant level is usually high on the list of suspects.

Refrigerant recharges sound cheap until you factor in the labor to find the leak, seal it, and recharge. A simple recharge runs $150 to $400. If the coil is leaking and needs replacement, you're looking at $1,500 to $2,800 for an evaporator coil swap, sometimes more depending on unit size and accessibility. If the leak is in the condenser outside and it's an older R-22 system, replacement of the whole outdoor unit can run $3,000 to $5,000 — and R-22 refrigerant has been phased out, so that system has a ticking clock on it regardless.

The other thing June does is stress the drain line. The evaporator coil pulls humidity out of the air — that's condensate, and it has to go somewhere. It drains into a pan and out through a PVC line, usually to the exterior or into a laundry standpipe. In summer, that line is working overtime. Algae grows fast in warm, wet PVC. A clogged condensate drain backs up into the pan, overflows, and drips into your ceiling or down your walls before you ever know there's a problem. I've seen $4,000 to $9,000 in drywall and insulation damage from a condensate line that was never flushed.

If you're buying a home in the Alvin, Manvel, or Webster area this summer, make sure your inspection includes a look at the air handler, the drain pan, and that suction line insulation. It's not glamorous stuff, but it's the difference between a comfortable June and a very expensive one.

If you've got questions about what I look at on an HVAC system during an inspection, feel free to reach out. I'm happy to talk through it before you schedule.