What To Do With Your AC on Vacation

Written By Lester Mclaughlin
Updated On

Are you wondering what to do with your AC unit when you’re on vacation?

You’ve come to the right place!

In this Blue National HVAC guide, you’ll learn:

  • Considerations for leaving your AC on or off while vacationing
  • The recommended thermostat setpoint while you’re away
  • The dangers of leaving your AC off while on vacation

And much more!

What To Do With Your AC On Vacation

So, if you’re looking for answers on what to do with your air conditioning unit when you take a vacation, keep reading our detailed guide below to get answers to all of your questions!

Factors To Consider When Deciding Whether To Leave The AC On Or OFF

If you’re planning to leave for a vacation, you might be considering ways to reduce the energy usage of your home while you’re gone. After all, you won’t be there, so why waste money on keeping your AC running? This begs the question, is it safe to turn the AC entirely off? Or is it better to turn the setpoint on the thermostat really high? 

Fortunately, we have the answer – all HVAC experts will recommend that you keep your air conditioner on while on vacation. However tempting it may be to turn it off and gain massive energy savings, it will be detrimental to your home. 

However, if you do choose to turn your air conditioner off, consider the following factors. 

Local Weather Forecast

If the forecast while on vacation is relatively mild, it should not be an issue if you turn off your air conditioner. 

However, if there are higher than average temperatures expected (greater than 75ºF to 80ºF), keep your air conditioner running. You can set your thermostat to a setpoint higher than usual. 

One key reason for this recommendation is to take the stress off your refrigerator or freezer on hot days. If it’s 80ºF outdoors, your home may get 10ºF warmer if it is in direct sunlight. In this case, your refrigerator and freezer would have to work overtime to keep chill. 

Additionally, if you leave any pets at home while you’re away, this level of heat could be detrimental to their health and well-being.

Vacation Length

If your vacation is only a few days long, it is better to set your AC to a higher temperature and keep it running. Cooling the house while you’re away at your desired “comfort temperature” is unnecessary. It can be higher since you won’t be home. 

On the other hand, if your home will be unoccupied for a week or longer, consider turning it off completely if the outdoor temperature is mild. However, if it will be scorching, leave it on at a higher set point.


The insulation in your home is critical in blocking out the hot air of the outdoors in the summer. If your home has poor insulation and takes in a lot of heat from the attic, windows, and poorly sealed doors, you should consider leaving the AC running. 

Poorly insulated homes stabilize with the outdoor temperature faster because they leak air and easily transfer heat. Increasing the insulation in your attic and improving the sealing around your windows and doors will slow the heat buildup in your home. 

If you improve the insulation and reduce air leaks, your home will remain at a more stable temperature if you leave your AC off while you vacation. However, turning it completely off is usually not a good idea if temperatures will be extreme. 

What Is The Recommended Thermostat Setting When On Vacation?

If you leave your air conditioner running while on vacation, the United States Department of Energy (U.S. DOE) recommends you keep your set point no higher than 85ºF to 90ºF.

They recommend this because it is enough to remove excess humidity from your home, and it won’t be too much stress on other appliances such as refrigerators. 

What Are Some Maintenance Practices To Keep Your AC Running In Your Absence?

Routine maintenance and yearly tune-ups are the best way to prevent your AC unit from breaking down and requiring costly repairs. Additionally, maintenance and tune-ups extend the lifespan of your air conditioner.

Here are three maintenance tasks you should do with your AC unit before leaving for an extended vacation. 

Replace the Filter 

Before you jump on a jet plane or a cruise ship, check your air conditioner’s filter. If the air filter is full of dust, replace it. Keeping an eye on your HVAC filter is a task you should be doing anyway. 

However, since you’re leaving for an extended period of time and keeping the AC running, you should check it outside of your regular intervals. This will ensure that your air conditioner does not run into issues while you’re away due to a clogged filter. 

Depending on your indoor air quality and the type of filter, you should replace the air filter every 3 to 12 months. 

Check the Temperature Differential

The temperature differential (Delta T) is the difference in temperature between the air blowing out of your supply vents and the air flowing into your return vent. 

If your AC unit is functioning correctly, The Delta T should be between 15 to 20 F. For example, if the return air measures 80, the supply air should be 60 to 65. 

If the Delta T is lower than this, your AC unit has an issue that an HVAC technician should address before you leave for the vacation. 

Get a Tune-Up

A tune-up from an HVAC professional will ensure that your cooling system runs in tip-top shape before you head out the door for your trip. 

During a tune-up, an HVAC technician will oil the blower motor and compressor, check the fan belt, inspect the coils for leaks, and do various other checks to ensure your air conditioner is up to snuff while you are away. 

What Are The Dangers Of Turning Your AC OFF During A Vacation?

Turning your air conditioner full off when you leave for vacation runs various risks. It could damage your home, electronics, and appliances-not to mention all the melted chocolate that will be waiting for you in your pantry when you get back home. 

Here are the common dangers of leaving your air conditioner off during a vacation. 

High Humidity 

While an air conditioner is removing the heat from your home, it is also removing humidity. As warm air blows across the cold evaporator coils in your air handling unit, its moisture condenses onto the coils when the air temperature drops. 

Obviously, if your air conditioning system is off, it will not be removing any moisture from your home’s air. Therefore, if you live in a humid area, leaving the AC off too long could result in:

  • Musty smells and odors due to mildew and mold
  • Damage to electronics 
  • Condensation on the windows
  • Ideal, moist conditions for insects
  • Warped wood furniture and hardware

For the comfort and safety of your home, it is best to keep your home’s indoor humidity at less than 50%. 

So, if you live in a climate zone with an average Relative Humidity of 30%, it should be okay to leave your AC off (barring excessive heat). Those in humid climates with an average RH of 50% or greater should always keep their AC running. 

Damage to Electronics

Inside all electronic devices are circuit boards that act as the brains of these devices. Circuit boards have various wires, resistors, capacitors, inductors, and other components with solder connecting them together. 

High temperatures can melt these solder joints, which will prevent your electronic devices from working correctly. Additionally, if they experience excessive moisture from high humidity levels, the circuit boards can short circuit, breaking the device. 

Refrigerator and Freezer Failure 

Most refrigerators and freezers are designed to work at indoor temperatures (60º-85ºF). If the indoor temperature gets too hot, the units will run excessively, leading to overheating and failure. 

Even if the refrigerator or freezer doesn’t break down, they will use up an excessive amount of electricity to keep your food cold. If the goal of turning off your AC unit is to save money, think again. Refrigerators and freezers running 24/7 may counteract any energy savings from no AC usage. 

To ensure the safety of these appliances, keep your central air conditioner on but at a higher setpoint.

Other Tips To Prepare Your Home’s AC For Summer Vacation

Besides increasing the temperature on your thermostat’s setpoint, there are other practices homeowners should consider to save energy.

To best prepare your home for your vacation, look into the following items to maximize your energy savings while you are away. 

Use a Smart Thermostat

You can program smart thermostats to run if the humidity or temperature in your home gets too extreme while you are away. It provides a perfect balance of “leaving your AC off” and “turning the setpoint higher.”

Plus, many smart programmable thermostats connect to wi-fi and can be accessed remotely through an app on your phone while sipping a Mojito on the beach. 

Close Blinds and Curtains

Keeping your blinds and curtains closed will block out the sunlight, which will keep your home’s temperature lower. Additionally, they will provide a slight improvement in insulation. 

Turn Off Your Water

Have you ever heard horror stories of people returning from vacation to a flooded and water-damaged home? To prevent any leaks from springing up, turn off your main water supply before you pack your luggage in your car. 

Leave the Light On

Leaving a light or two on near windows will deter most criminals from breaking into your home while you are away. 

Unplug Electronics

While you are gone, most of your electronic devices will not be in use. Don’t just turn them off; unplug them. If they are just “off,” they still consume a small amount of electricity.

Water Heater

If you are away for an extended period, consider turning your water heater’s temperature setting to the lowest possible temperature. Just remember to turn the temperature back up when you return. Otherwise, you’ll be in for a cold shock when you jump in the shower. 

Meet Your HVAC Expert

Lester Mclaughlin

HVAC systems are highly technical and often is the most misunderstood part of the house. From ductwork to heat pumps, I've been exposed to all sorts of issues facing homeowners. It really irks me when a homeowner is given bad advice like refilling freon vs fixing a leak in the system. I'm here to help our website readers with their heating and a/c problems.
More HVAC Guides
Signs Your AC May Need A Refrigerant (Freon) Charge
What Is Refrigerant & How Does it Help AC
Are Variable Speed AC Worth The Cost
Air Filter Vs. Air Purifier
The Humidity & Temperature In Home

Request A Free Quote

By submitting your info on this form, you are agreeing to be contacted regarding your service request by means of telephone, email, or text including using pre-recorded or auto dialed phone calls or text messages to the phone number you have provided, including your wireless number, if provided. Consent to contact doesn’t require you to purchase service. Please note you may be matched to one of our trusted partners such as Craft Jack or Angi. By using this service, you agree to our Terms Of Service as well as to Angi Terms of Service and Privacy Policy.


Fast Free Quotes
Expert HVAC Technicians
Punctual Service
Best Pricing
Simple Payment Plans
Satisfaction Guarantee




emergency repair service


We have a project manager on call 24/7/365 to dispatch our professionals. That means whether you need service on weekends, holidays, or evenings, we’re there for you when you need us most!


Blue National HVAC delivers rapid and reliable service for all your heating and cooling equipment at the simple click of a button. Our friendly and professional team has decades of experience and is ready to help solve your HVAC problem in no time at all!

Contact Us | Terms and Conditions | Privacy Policy