To protect your AC in extreme heat, keep the filter clean, keep the outdoor unit clear and help the house hold its cool. Quality Service Company, LLC has served homes in Florence, SC since 2003. A checkup before the heat arrives lets a tech look the system over.
How hard does a Florence summer work your AC?
NOAA climate normals for Florence Regional Airport show a July average high of 92 degrees. The average July low is about 72, so nights bring little relief.
In a normal year, Florence sees about 70 days at 90 degrees or higher. About 55 of those fall in June, July and August. About three days a year reach 100. Cooling demand runs high from May through September.
Some days go well past normal. The airport hit 103 degrees on July 27, 2025. It reached 100 on July 5 and again on July 8, 2026. The record is 108, set on June 27, 1954.
That means long run times, day after day.
Why does humidity matter as much as heat?
Your AC does two jobs. It cools the air, and it pulls water out of it. That water drains out through a line near the indoor unit.
Florence air holds a lot of moisture. Older NOAA engineering data for Florence count nearly 3,000 hours a year that meet its humid-area criteria for air conditioning.
The EPA says to keep indoor humidity below 60 percent, and ideally between 30 and 50 percent. Damp air can feed mold.
Signs the moisture is winning:
- Rooms feel clammy, even at your usual setting.
- You smell something musty when the system runs.
- Windows or vents sweat.
A thermostat with humidity settings or a whole-home dehumidifier can help. Read about thermostat, air and humidity upgrades.
What can you do to help your AC keep up?
Most of these take a few minutes and no tools.
- Check the filter often in summer. Change it when it looks gray or dusty, because a clogged filter chokes airflow.
- Keep grass, weeds and stored items away from the outdoor unit. It needs open air on every side.
- Keep indoor vents open and clear of rugs and furniture.
- Close blinds on sunny windows in the afternoon.
- Run ceiling fans where people are sitting. Fans cool people, not rooms, so turn them off when you leave.
- Cook, bake and run the dryer in the morning or evening.
- Pick a setting and leave it. Setting the thermostat very low does not cool the house faster.
What should a technician handle?
Some parts are better left alone. The coils, refrigerant and electrical parts take training and tools to check safely.
A spring checkup lets a tech look the system over. Plan it before cooling runs hard in May. Learn more about HVAC maintenance and tune-ups.
What are the signs your AC is struggling in the heat?
- Warm or weak air from the vents.
- The house never reaches your setting, even after sunset.
- Ice on the copper lines or the indoor unit.
- Water pooling near the indoor unit.
- A breaker that trips.
- New sounds, like grinding, squealing or loud buzzing.
If you see ice, turn the system off at the thermostat and let it thaw. If a breaker trips again after you reset it, leave it off. Both are signs to call for service.
How do summer storms affect your AC?
Afternoon thunderstorms are part of summer here. On July 8, 2025, lightning started structure fires in Florence County.
Trane suggests turning the AC off at the thermostat and breaker before a big storm. Trane also suggests an HVAC surge protector. If the outdoor unit sat in floodwater, have it inspected before you turn it back on.
If you run a portable generator, keep it outdoors. The CDC says to keep it more than 20 feet from windows, doors and vents. Never run it in a garage.
When should you call for help?
Don’t wait out a hot night if someone at home can’t handle the heat. That includes an older parent, a new baby or anyone with health needs.
We have 24/7 dispatch for HVAC. Call (843) 920-2004 or book online.
Common questions
Is it bad for my AC to run all day in a heat wave?
Long run times are normal on the hottest Florence afternoons. A healthy system may run for hours when it is 90 degrees or more outside. The warning sign is a house that never reaches your setting, even late at night. That means something is limiting how well it cools, and a technician should find the cause.
Should I turn my AC off when I leave for the day?
Raising the setting a few degrees usually works better than turning the AC off. When the system sits off all day, heat and humidity build up inside. The AC then has to catch up during the hottest hours. A programmable or smart thermostat can start cooling before you get home.
What should I do if my AC stops cooling on a very hot day?
When an AC stops cooling, check the thermostat setting, the filter and the breaker first. If you see ice on the lines, turn the system off so it can thaw. Close the blinds, run fans and keep everyone in the coolest room. Then call Quality Service Company at (843) 920-2004. We have 24/7 dispatch for HVAC.
Does a bigger AC cool better in the heat?
No, a bigger AC does not cool a house better. An oversized unit cools the air fast and shuts off before it removes enough moisture. The house can feel cool and damp at the same time. Size should come from a load calculation for your home, not the size of the old unit.