When summer temperatures soar, air conditioning (AC) becomes a lifeline for comfort. While we all love to come into the ice-cold air after a sweltering day, a common debate still goes on in many households and offices. Which is better — turning the AC on and off versus leaving it on?
This question is especially important for anyone looking to balance energy efficiency, cost savings, and overall comfort. With the complicated nature of how AC systems work, the truth is usually more nuanced than a simple yes-or-no answer.
In this blog, we’ll explore the pros and cons of each approach, the key factors that influence energy efficiency, and practical tips to help you make an informed decision for running your AC.
Quick Answer: Turning AC On and Off Versus Leaving It On
In many situations, turning the AC on and off as needed is more cost-effective than leaving it on continuously. When you’re away from home for extended periods, it’s more energy-efficient to turn off the AC or set it to a higher temperature. This prevents unnecessary energy consumption while you’re not using the cooled space. Leaving it on all day can result in higher energy bills, especially if your home is poorly insulated. But for shorter absences or when maintaining a specific temperature is crucial, leaving it on is generally the better option.
Factors That Influence the Decision
The answer isn’t one-size-fits-all. Several key factors determine whether turning the AC on and off or leaving it on all day is the more efficient choice for your specific situation. Let’s take a closer look at the key considerations.
Duration of Absence
The longer you’re away from home, the more it makes sense to turn off your AC. For shorter periods of a few hours or less, it may not be as beneficial to power down, as the system will have to work harder to cool the house back down. But if you’re leaving for a workday, vacation, or any period longer than a few hours, turning the system off or setting it to a higher temperature can result in significant energy savings. A notable exception could be in extremely humid climates like Florida, where extended exposure to moisture could cause damage or increase the risk of developing mold.
Insulation of Your Home
The quality of your home’s insulation plays a significant role in determining which approach works best. Well-insulated homes retain cool air longer, so you’ll benefit more from turning the AC off during absences. In homes with poor insulation, indoor temperatures can rise quickly, causing the AC to work harder upon restart. In such cases, leaving the AC on at a higher thermostat setting may be more efficient.
Efficiency of Your AC Unit
Modern, energy-efficient AC units are designed to cool spaces quickly and efficiently, making turning your AC on and off versus leaving it on less of a dilemma. However older units may require more time and energy to restore a cool temperature. If you’re using an older model, you’ll want to weigh this factor more heavily in your decision.
Local Climate and Weather Conditions
If you live in a region with extreme heat and high humidity, it’s more challenging to maintain comfortable indoor temperatures. In these climates, leaving the AC on — but at a higher setting — might be more efficient. On mild or breezy days, turning it off entirely may be a better option. Humidity control is also important since high humidity can make your home feel hotter than it actually is.
Type of Thermostat You’re Using
Smart thermostats make it easier to optimize your AC usage. You can schedule temperature changes or control your AC remotely, making turning the AC on and off versus leaving it on less of an issue. With a smart thermostat, you can turn off the AC when you’re not home and schedule it to start cooling shortly before you return, ensuring comfort without unnecessary energy usage.
How Each Approach Affects Cost and Efficiency
To fully understand whether turning your AC on and off versus leaving it on is better, you need to understand how it affects energy consumption and costs.
Energy Usage
Turning your AC on and off saves energy because it does not run continuously. When you’re away, your home’s temperature rises, but you avoid running the system during this period. Upon return, it may take time and energy to cool your home again, but this cost is typically less than leaving the AC running for hours when no one is home.
Wear and Tear
Some people believe frequent stops and starts will cause more wear and tear on the AC unit. While it’s true that compressors experience a surge of energy during start-up, modern AC systems are built to handle this. Consistent long-term use—such as leaving the AC on continuously—can also accelerate wear and tear on components like the fan and compressor.
Cost Analysis
The cost difference depends on factors like electricity rates, local climate, and your AC’s efficiency. Running the AC continuously for eight or more hours daily can result in much higher energy bills than turning it off during work hours and cooling it down when you return. Using a programmable thermostat to adjust the temperature while you’re away can significantly cut cooling costs.
Tips to Maximize AC Efficiency
No matter your chosen approach, there are ways to improve your AC’s efficiency and lower energy costs. Here are some simple yet effective tips:
- Install a Smart Thermostat: Use it to create a cooling schedule and control your AC remotely. Smart thermostats optimize when to turn the system on and off, eliminating much of the guesswork.
- Seal Air Leaks: Check windows, doors, and attic spaces for air leaks. Sealing these gaps prevents cool air from escaping and keeps your home cooler for longer.
- Use Blinds and Curtains: Sunlight streaming through windows can raise indoor temperatures. Close blinds and curtains during peak daylight hours to reduce the load on your AC.
- Use Fans for Air Circulation: Ceiling and portable fans circulate cool air, helping you feel cooler without lowering your thermostat.
- Maintain Your AC Unit: Clean or replace air filters regularly, schedule annual tune-ups, and ensure the system’s coils and fins are clean to keep your AC operating at peak efficiency.
- Upgrade to an Energy-Efficient Model: If your AC is over a decade old, upgrading to a newer, energy-efficient model can result in substantial energy and cost savings.
- Avoid Setting Your Thermostat Too Low: Each degree you set the thermostat lower increases energy use by about 3%. Set it at 78°F (26°C) when you’re home and higher when you’re away.
- Use a Dehumidifier: Removing excess moisture from the air makes your home feel cooler, allowing you to set the AC at a higher temperature while staying comfortable.
Turning AC On and Off Versus Leaving It On — Final Verdict
When it comes to turning the AC on and off versus leaving it on, the clear winner for most households is to turn it off or raise the temperature when you’re not home. This strategy reduces energy usage, lowers utility bills, and doesn’t significantly increase wear and tear on modern AC units. But if you’re only away for a short period, keeping the AC running at a higher temperature might be a better option to avoid overburdening the system when you return.
Your home’s insulation, the efficiency of your AC unit, and your personal comfort preferences all play a role in making the best decision. To maximize efficiency, consider upgrading to a smart thermostat, sealing air leaks, and using fans to circulate cool air. By taking these steps, you’ll strike the right balance between comfort, cost, and energy efficiency, no matter which method you choose.
Call Complete Air Mechanical for AC Service in Orlando
If you have questions about turning your AC on and off versus leaving it on, Complete Air Mechanical is here to help. Our family-owned and operated team has served Central Florida since 1992, providing expert HVAC services from routine maintenance to emergency repairs. Whether you want to know about optimal operating conditions, need regular preventive maintenance, or are shopping for a more energy-efficient system, we have you covered!
If you live in Longwood, Seminole, Orange, Osceola, or Volusia, contact us today to schedule your service.
Schedule Service Online or call us at (407) 915-0144.