Every July the same question goes around Houston neighborhoods: why is my electric bill so high this summer when I have not changed anything? The frustrating answer is that you probably did not change anything. Your house did not either. What changed is the weather, and your house was never built to handle it well.
What is actually driving a high summer bill in Houston
Cooling is the largest single line in a Gulf Coast electric bill from roughly May through October. Everything else, lights, appliances, electronics, stays broadly flat year round. So when the bill climbs, it is almost always the air conditioner running more hours, not the rest of the house suddenly getting hungry.
The question worth asking is not how do I use less electricity. It is why is my air conditioner running so many hours. There are usually four answers, and they stack.
1. Your attic is a heat source sitting on your ceiling
A conventional vented Houston attic reaches 130 to 150 degrees on a summer afternoon. That heat radiates down through the ceiling into your living space all day and keeps releasing into the evening long after the sun goes down. If your bill spikes in the afternoon and the house stays warm until late, this is the reason.
2. Your ducts are in that attic
The large majority of homes in this city run their ductwork and air handler through the attic. So the cold air you paid to produce travels through a 140 degree space on its way to your rooms, losing capacity the whole distance. Any leak in that duct system dumps conditioned air straight into the attic, and pulls hot attic air back in on the return side.
3. Air is leaking through the building envelope
Top plates, wire and plumbing penetrations, recessed lights, the attic hatch, the rim joist where the floor meets the foundation. Individually small, collectively a permanent opening. Hot humid air pushes in continuously and your system has to remove both the heat and the moisture that came with it.
4. Your insulation is not doing what you think
Blown insulation settles and drifts. Batt gets compressed and gapped. Both are filters rather than air barriers, so even at full depth they do nothing about point three. Most homes we inspect have insulation that is performing well below its label.
Why humidity makes it worse here than elsewhere
Your air conditioner does two jobs: lower the temperature and remove moisture. In a dry climate it mostly does the first. On the Gulf Coast it spends a large share of its capacity on the second, because every cubic foot of outside air that leaks in arrives loaded with water that has to be condensed out before the house feels comfortable.
This is why a house can sit at 74 degrees and still feel clammy, and why people push the thermostat down to 71 chasing a comfort problem that is really a humidity problem. Sealing the envelope reduces the moisture load, which often lets you sit comfortably at a higher setpoint. That is a real saving that never shows up as a change in behavior.
What to check yourself this week
- Look at the attic. Can you see the tops of the joists? Then the insulation has settled below its original depth.
- Feel the ceiling in an upstairs room at 5pm. Warm to the touch means heat is coming through.
- Check the attic hatch. Uninsulated and unweatherstripped is a hole in your ceiling.
- Watch the system. If it runs almost continuously through the afternoon and never satisfies, it is fighting a load it cannot win.
- Compare rooms. A large gap between downstairs and upstairs points at the attic, not the thermostat.
What actually reduces the bill
In rough order of impact for a typical Houston home:
- Get the ducts out of the heat. Spraying foam at the roof deck brings the attic inside the conditioned envelope, so ducts and equipment are no longer in a 140 degree space. See attic insulation.
- Air seal the ceiling plane if the ducts are not in the attic. Cheaper, and most of the benefit in that specific case.
- Seal the walls and rim joist. See wall insulation.
- Add depth where existing material is clean and dry but thin. Fiberglass does this cheaply.
- Service the equipment. A dirty coil or low charge makes everything above work harder.
An honest word about savings numbers
You will find contractors quoting specific percentages. We do not, because the honest answer depends on your equipment, your duct condition, your windows, your shade and how you actually run the house. What is reliable is the direction: in this climate the attic and the envelope are where the summer load comes from, so that is where the money goes furthest.
Frequently asked questions
Would a new air conditioner fix this?
It will run more efficiently, but it will still be fighting the same heat gain and the same air leakage. Sealing the envelope first often lets your HVAC contractor size the replacement smaller, which saves money twice.
Should I just raise the thermostat?
It helps, and it is free. But if the reason the house feels bad at 76 is humidity rather than temperature, raising it further will not be comfortable. Fix the moisture load and a higher setpoint becomes livable.
Do radiant barriers work?
They reduce radiant heat gain and can help. They do nothing about air leakage or duct losses, which are usually the larger problems in a Houston home. They are a supplement, not a substitute.
How do I know which fix my house needs?
Where your ductwork runs is the deciding factor, followed by the condition of what is already in the attic. That is exactly what a free inspection establishes.
Find out what your house is doing
We go up, photograph what we find and tell you which fix applies, in writing. Call (346) 775-9128 or request a free estimate.