How to Prepare Your HVAC System for Vacation: Energy-Saving Tips

Before you leave for vacation, it’s easy to focus on luggage and logistics—but don’t forget about your home’s HVAC system. With a few small adjustments, you can reduce energy use, protect your indoor environment, and return to a comfortable space without issues.

Before leaving your home, you’ve probably wondered what temp to set your AC when on vacation. This guide provides simple and effective HVAC preparation tips, including temperature settings to keep your system running efficiently while you’re away so you don’t come home to a costly surprise.

Why You Shouldn’t Turn Off HVAC Completely

Instead of asking the question, “What temp should I leave my AC on when on vacation?”, some homeowners shut off their HVAC systems completely. While it might seem smart to shut off your HVAC system while you’re gone, turning it off can backfire. Instead of saving energy, you could come home to damage caused by humidity, extreme temperatures, or poor airflow.

Here’s why turning off your HVAC isn’t always a good idea:

• Humidity buildup can lead to mold and mildew growth, especially in humid climates.
• Wood floors and furniture may warp, crack, or expand without consistent temperature and humidity control.
• Electronics can overheat if left in a sealed, uncooled home during hot summer months.
• During the winter, pipes can freeze without baseline heating, even in mild climates where temperatures can drop unexpectedly.

The better approach? Leave your HVAC running at a reduced setting. This keeps air circulating, protects your home’s structure and contents, and uses far less energy than full operation.

Ideal Thermostat Settings for When You’re Away

The right thermostat setting can save money while still protecting your home. So, what temp should you leave your house on vacation? It depends on the season and what’s inside your home.

Recommended Vacation Settings:

• Summer: Set the thermostat to 78–85°F. This keeps your home safe without running the AC constantly.
• Winter: Set the heat to 55–60°F to prevent freezing and minimize energy use.

Adjust Based On:

• Pets at home: Avoid letting the home get too hot or too cold.
• Electronics & plants: Sensitive items may need more stable temperatures.
• Your region’s climate: In hot areas like Arizona, lean toward the lower end of summer settings.

Setting your thermostat correctly while away is the most effective way to cut energy bills without risking damage. If you’re wondering what temp to set the AC when on vacation, 80°F is often a sweet spot for short summer trips.

Use Your Thermostat’s Vacation or Eco Mode

Many modern thermostats include an eco mode or vacation setting that adjusts your system automatically while you’re away. This feature helps you maintain ideal temperatures without having to constantly adjust the controls.

Benefits of Vacation/Eco Mode:

• Automates energy savings without turning off your HVAC entirely
• Maintains airflow and comfort for pets, electronics, and materials
• Prevents short cycling by keeping settings stable
• Reduces wear and tear on your system

If you own a smart thermostat, you can take it a step further. Many models let you:

• Adjust temperatures remotely from your phone
• Get alerts if temperatures or humidity reach unsafe levels
• Monitor energy usage and adjust schedules automatically

Clean and Replace Air Filters Before You Go

Before departing, understanding what to set the AC at when on vacation isn’t the only thing to consider. One of the easiest things you can do is check your air filter. A clogged or dirty filter restricts airflow, forces your system to work harder, and lowers indoor air quality.

Replacing or cleaning the filter helps your HVAC system run smoothly while you’re away, even at a reduced setting.

Benefits of fresh filters before travel:

• Improves airflow during minimal operation
• Reduces strain on your HVAC system
• Helps trap dust and allergens
• Extends system lifespan

Most manufacturers recommend replacing filters every 1 to 3 months, but it’s especially important to do so before an extended trip. If you’ve recently had construction work done or live in a dusty environment, check your filter even sooner.

Keep Vents and Register Areas Clear

It may be tempting to close off vents in unused rooms to save energy, but doing so can actually cause more harm than good. Closing vents can create pressure imbalances in your ductwork, resulting in reduced efficiency and potential damage over time.

Vacation airflow checklist:

• Leave all vents open, even in unused rooms
• Ensure furniture and rugs aren’t blocking registers
• Wipe down vents to remove dust or buildup
• Keep interior doors open to allow air to circulate evenly

Proper airflow ensures your HVAC system can maintain consistent indoor temperatures with less effort.

Maintain the Outdoor Unit

Before you leave, take a few minutes to check your outdoor condenser unit. Debris, overgrown plants, or even patio furniture can block airflow, causing your system to overheat.

Quick outdoor unit prep:

• Clear away leaves, branches, or mulch within two feet of the unit
• Trim back shrubs or grass to create breathing room
• Check for visible obstructions that could block airflow
• Gently rinse coils with a hose (if your system’s manual allows it)

This small effort helps your AC run efficiently, even on eco mode, while you’re gone.

Seal Windows, Doors & Control Solar Heat Gain

Keeping heat out during summer—or inside during winter—starts with good insulation. That means sealing leaks and reducing solar heat gain before you leave.

Energy-saving sealing tips:

• Close blinds and curtains to block sunlight and heat
• Use thermal blackout curtains in rooms with direct sunlight
• Check door and window seals for cracks or gaps
• Apply weather stripping or caulk around problem areas
• Inspect the attic and crawl spaces for air leaks

A few hours of sealing and shading can significantly reduce your HVAC system’s workload, especially in sun-drenched regions like the Southwest.

Control Humidity and Prevent Mold

Even when you’re away, your home still needs basic humidity control. Without airflow and ventilation, high humidity can promote mold growth, musty odors, and damage to wood.

Tips to control humidity while away:

• Use a dehumidifier in basements or high-moisture areas
• Keep indoor humidity between 30–50%
• Leave interior doors open to help air circulate
• Use a smart thermostat with humidity monitoring (if available)

If your home is prone to excessive humidity, consider investing in a whole-house dehumidifier or consulting your HVAC provider before your trip.

Perform Leak Checks & Schedule Inspection

Before leaving town, give your HVAC system a quick check for signs of wear, leaks, or clogs. Addressing these issues before your vacation reduces the risk of returning to a costly mess or broken system.

What to look for:

• Refrigerant leaks around the outdoor unit or visible tubing
• Water pooling near the condensate drain line or drain pan
• Unusual odors or sounds from the unit while running
• Clogged or slow-draining lines that could back up

Want peace of mind while you’re away? Schedule a pre-vacation HVAC inspection. The technicians at Chandler Air can identify early issues, tune up your system, and ensure it’s safe to run on reduced settings while you’re gone.

Pre-Cool Strategically & Use Off-Peak Times

If your home is part of a time-of-use utility plan, running your AC during off-peak hours can save energy and cut costs. This strategy is even more helpful before you leave for vacation.

How to pre-cool your home:

• Lower the temperature early in the morning or late at night
• Run ceiling fans to help distribute cool air
• Set your thermostat higher right before you leave to maintain baseline cooling

This method keeps your home comfortable during the day without forcing the system to run at peak electricity prices.

Consider Smart Technology & Remote Monitoring

Answering the question “What temp should I leave my AC on when on vacation?” is easier than ever with smart technology. Smart thermostats provide remote control of your home’s temperature, humidity, and energy usage while you’re away. With just a few taps on your phone, you can:

• Adjust settings in real time
• Receive alerts for temperature spikes or equipment issues
• Monitor indoor humidity
• Track energy usage trends
• Integrate with home security systems for added safety

Some models even learn your habits and optimize your system for maximum efficiency over time.

Schedule Your HVAC Pre-Vacation Tune-Up

Now that you know what temp to set the AC when on vacation, give yourself peace of mind by scheduling a professional HVAC tune-up before you head out of town. A quick inspection and service call can ensure your system is ready to maintain comfort and efficiency while you’re away and mitigate the risk of breakdowns or damage.

Why schedule a tune-up before vacation?

• Catch small problems before they become major issues
• Ensure proper airflow and filtration
• Verify that eco or vacation modes are set correctly
• Protect your investment and improve long-term efficiency

Even if your system appears to be running fine, a trained technician can check refrigerant levels, test safety controls, and clean key components to ensure everything works as it should.

If you’re planning a trip, don’t wait until the last minute. Contact our team to book a pre-vacation HVAC inspection today and travel with confidence.