Why Lowering Your Thermostat Doesn’t Cool Your Home Faster

During a Memphis heat wave, it’s tempting to walk inside and crank your thermostat way down—maybe to 60°F or even lower—hoping your home will cool off faster. But here’s the truth: setting your thermostat lower does not make your air conditioner blow colder air or cool your home more quickly. It only controls how long your system runs. And when it’s extremely hot outside, setting your thermostat unrealistically low can cause your system to run nonstop, waste energy, and still struggle to hit the temperature you selected.

At Gentry’s Heating & Cooling, we help homeowners across Memphis, northern Mississippi, and eastern Arkansas understand how their HVAC system really works—so you can stay comfortable, avoid unnecessary breakdowns, and keep your energy bills under control.

What Your Thermostat Actually Does

Your thermostat is not a “speed control” for your AC system. It’s more like a temperature target. When you set it to a certain number, your thermostat tells your air conditioner to run until the indoor temperature matches the setting. That’s it.

Whether you set it to 78°F or 60°F, your AC produces the exact same temperature air. A properly functioning air conditioner typically blows air that’s 15–20 degrees cooler than the air entering the system. It can’t magically produce colder air just because the number on the thermostat is lower.

Why Your Home Doesn’t Cool Faster With a Lower Setting

This is one of the biggest myths we hear during Memphis summers. Many people assume setting the thermostat lower will hurry things along. In reality, your AC unit works at one consistent speed. Lowering the thermostat doesn’t “boost” it—it simply tells it to run longer.

If it takes your system 20 minutes to cool your home by 2 degrees, it will still take 20 minutes to cool it by 2 degrees regardless of whether you set the thermostat to 74°F or 60°F. The system doesn’t know you’re in a hurry!

When It’s Extremely Hot Outside, Your AC Has Limits

On scorching Memphis days—when temperatures hit the high 90s or triple digits—your air conditioner may struggle to pull your home down to very low thermostat settings. All systems have a limit to how many degrees of cooling they can handle against the outdoor temperature.

For example, if it’s 100°F outside and you set your thermostat to 65°F, your AC might run for hours without ever reaching that number. This doesn’t mean your AC is broken—it means the outdoor heat load is simply too great for the system’s design capacity.

In these situations, setting an extremely low temperature only forces your AC to run nonstop, increasing wear and tear and raising your utility bills.

What Happens When Your AC Runs Constantly

Running continuously isn’t good for your system. It can lead to:

• Higher energy bills thanks to long run times
• Increased wear and tear on motors, compressors, and other components
• Reduced system lifespan because the unit never gets a break
• Frozen coils if the system is already struggling or airflow is restricted
• Inconsistent cooling because the system can’t keep up with demand

These are some of the most common issues we see during summer service calls throughout Shelby County, DeSoto County, and the surrounding Memphis metro area.

The Smart Way to Set Your Thermostat

Instead of cranking your thermostat way down, try these best practices:

• Choose a realistic temperature —Most homes stay comfortable around 74–78°F in the summer.
• Make gradual adjustments —Instead of dropping the temperature 10 degrees at once, lower it a few degrees at a time.
• Use a programmable thermostat —Let it adjust automatically throughout the day for better efficiency.
• Keep blinds and curtains closed —Especially on west-facing windows during the hottest part of the day.
• Change air filters regularly —A clogged filter makes your system work harder for worse results.

These small steps can make a big difference in how comfortable your home feels and how efficiently your AC runs.

When Your AC Seems to Run Constantly

If your air conditioner never cycles off—even when your thermostat is set to a reasonable temperature—it may be a sign of a problem, such as:

• Low refrigerant
• Dirty coils
• Blocked ductwork
• A failing compressor or blower motor
• A system that’s undersized for your home
• Poor insulation or excessive heat gain

Our technicians at Gentry’s Heating & Cooling can diagnose the cause and get your system running efficiently again. We service all brands and offer fast repairs across Memphis, Germantown, Collierville, Cordova, Southaven, Olive Branch, West Memphis, and nearby areas.

How Gentry’s Heating & Cooling Can Help Improve Cooling Performance

Whether your home won’t cool down or your system struggles during extreme heat, we offer solutions that keep you comfortable:

• AC repair for units blowing warm air or running nonstop
• AC tune-ups to improve performance and efficiency
• New AC installations for older or undersized systems
• Ductwork repair to fix leaks and improve airflow
• Mini-split installation for hard-to-cool rooms
• Financing options for new system installs

As a family-owned, minority-owned Memphis HVAC contractor with over 25 years of combined hands-on experience, we’re committed to delivering reliable, honest service for every home and business we work with.

FAQ

Does lowering the thermostat make my AC blow colder air?

No. Your AC produces the same temperature air no matter what your thermostat is set to. Lowering the thermostat only makes it run longer.

Why does my AC run nonstop on hot days?

When it’s extremely hot outside, your AC may struggle to cool your home to very low settings. The system might run continuously trying to reach a temperature it simply can’t achieve based on its design capacity.

What temperature should I set my thermostat to in summer?

Most Memphis homeowners stay comfortable between 74–78°F. Setting the thermostat lower than that usually doesn’t cool faster—it just increases energy use.

Can running my AC nonstop damage it?

Yes. Constant operation increases wear and tear, raises energy costs, and can lead to coil freezing or premature system failure.

How can I get better cooling without overworking my AC?

Schedule regular maintenance, change your air filters, seal duct leaks, add shading where possible, and avoid setting extreme thermostat temperatures. If your system is older or undersized, a replacement may help.

If your AC can’t keep up with the Memphis heat, Gentry’s Heating & Cooling is here to help. Call us at 901-601-9701 for fast, reliable service you can trust.