DUCT SEALING PROS · SYMPTOMS
High AC Bill St George: Are Your Ducts to Blame?
A high AC bill St George homeowners see from June through September has several possible causes, and leaky ducts are one of the most common. When cooled air escapes into the attic, the air conditioner runs almost nonstop and the bill follows.
Why a high AC bill St George homes get is so common
St. George sits around 2,800 feet in the Mojave. July highs average about 104°F, nights stay near 74°F and the valley sees 100°F or more regularly from mid-June to mid-September, with 110°F events most summers. An air conditioner runs a lot in that climate, so any inefficiency shows up quickly on the bill.
When ducts leak, part of the air the system cools never reaches a room. The thermostat keeps asking for cooling, the system keeps running and the meter keeps turning. A high AC bill St George owners cannot explain is often this.
A high AC bill St George homeowners compare with neighbors tells you little, because homes differ in size, age and attic insulation. The useful comparison is your own house, this summer against last, and your ducts, before sealing against after.
Common causes of a high AC bill
| Cause | What it looks like | Check |
|---|---|---|
| Leaky ducts | AC runs nonstop, some rooms never cool | Duct leakage test |
| Dirty filter or coil | Weak airflow, ice or odd noises | Replace the filter, call for service |
| Old or undersized equipment | Cannot keep up on the hottest days | Equipment inspection |
| Weak attic insulation | House heats up fast in the afternoon | Attic inspection |
| Thermostat settings | Large setbacks followed by long recovery | Review the schedule |
Because several causes can combine, the first step is to rule out the cheap ones, then measure the ducts.
A seasonal pattern is the clue. If bills rise sharply in June and fall after September, cooling is the driver. If the rise is larger than last year with the same habits, the system is losing efficiency somewhere. Leaky ducts and a dirty filter are the two most likely culprits, and the filter is the easier of the two to rule out.
How leaky ducts raise the bill
Air lost from the ducts is air you paid to cool. Energy Vanguard, citing NREL research, notes that ducts in an unconditioned attic can add roughly 25% to the cooling load in a hot climate, even when well sealed. Add leaks and the system works against an oven.
A leakage test turns a vague worry into a number. If leakage is high, sealing is often the lowest-cost improvement available. See is duct sealing worth it for how to weigh the payback and duct sealing cost for published prices.
Leakage also explains why some homes feel uncomfortable and expensive at the same time. The system works hard, the bill climbs, and yet one room is still warm. That combination is the classic signature of air escaping before it reaches the register, and it is what a pressure test is designed to confirm.
What to do next
- Compare this summer’s bills with last summer’s, noting any changes in equipment or habits.
- Check the filter and make sure the registers are open.
- Look for signs of leaky ducts: rooms that never cool, dust around vents, weak airflow. See signs of leaky ducts.
- Book a duct leakage test for a measurement.
- If leakage is high, seal with mastic and foil tape, then retest.
If you are weighing the cost, Angi lists duct sealing at $500 to $4,000 nationally, plus about $300 for a pressure test. A high AC bill St George households are tired of is worth a test before you decide anything else.
Whatever you decide, keep the numbers. A leakage reading before and after sealing, next to two summers of bills, is the clearest picture of what the work achieved.
Frequently asked questions
Can leaky ducts really raise my electric bill?
Yes. Cooled air that escapes before reaching the rooms makes the system run longer.
How much will sealing save?
It depends on how leaky your ducts were and how hot your attic gets. We measure the change in leakage rather than promise a figure.
Should I replace my air conditioner first?
Not before testing the ducts. A new unit on leaky ducts still loses air.
How do I know the ducts are the problem?
A pressure test measures leakage. If it is low, the cause is elsewhere.
Ready to find out where your cool air is going?
Call us and tell us which rooms are giving you trouble. We will explain what a duct leakage test involves and book your duct sealing services St George crews can finish before the next heat wave.
Duct Sealing Pros
3430 S River Rd, St. George, UT 84790
(435) 281-0395