It is almost never the thermostat. We measure airflow room by room and prove the fix with numbers.
Spread between the coolest and hottest room. Anything over 3°F means air is not reaching the far end.
Most Houston homes we walk into have enough tonnage already. What they don't have is a duct system that delivers it evenly.
An oversized system short-cycles: it blasts cold air, satisfies the thermostat near the hallway, and shuts off before the back of the house ever catches up. You get cold spots, hot spots, and humidity that never drops. Replacing it with something bigger makes all three worse.
Crushed flex, disconnected boots and leaking plenums. In a Houston attic that runs 140°F in August, a leaking return is pulling that air straight into your house.
Dampers set with a flow hood, not by feel. Every register gets a measured CFM against what the room actually needs.
Room by room, with your real windows, insulation and orientation. It is the only honest way to size a replacement.
If the equipment is done we will say so, size it properly, and show you the math. We do not lead with it.
Static pressure at the handler, CFM at every register, temperature split across the coil, and a thermal sweep of each room.
Seal, repair or resize whatever is choking the run. Then set dampers to the numbers, not to whatever feels about right.
We re-measure every room and hand you the before and after sheet. If the spread is still over 3°F we are not finished.
Both are fine. The plan exists because coils foul and drain lines clog on a schedule, and because we would rather find it in March than in July.
Not interested in a plan? The one-off room-by-room airflow survey is $189, and it comes off the bill if you have us do the work.
"Two companies quoted me a five ton replacement. Meridian found a disconnected duct in the attic and charged me $340. The bonus room is finally usable."
"They handed me a sheet with every room measured before and after. Nobody has ever shown me numbers like that."
That one detail tells us more than a model number. We will bring the right instruments the first time.
(713) 555-0164A technician answers, not a dispatch service.