Save Cooling Costs Airbnb

The August electric bill comes in at $612 and you do the math: the place was empty for nine of those nights. Nine nights of the AC chugging away holding 68 because the family that checked out on the third left it set there before they walked out the door. If you have ever stared at a summer utility bill from a coastal rental or a desert property and wondered where all the money went, this is the playbook to save cooling costs at your Airbnb without making the next guests miserable. The trick is not refusing them comfort — it is making sure the house is not air-conditioning empty rooms for two-day gaps between bookings, and that your AC is not battling humidity it does not need to.

The setup is simple, the gear is cheap, and once it is in place it runs without you babysitting it. We will cover safe vacant temperatures for cooling, why humidity matters more than you think, and the small wording tweaks in your house manual that keep guests from cranking it to 65. If you want the broader context first, our overview on choosing an Airbnb energy saving thermostat that earns its keep year round sets the foundation.

Who This Is For

Hot-climate hosts. If you rent in Phoenix, Austin, Orlando, the Carolina coast, anywhere in Florida, the Gulf, southern California, or any other zone where summer cooling bills land in the high three figures, you are the audience. This also applies if you have a desert vacation home with long midweek vacancies, or a beach house that books heavily on weekends but sits empty Monday through Wednesday.

Humidity-prone properties get extra attention here. In Florida and Gulf coast homes, leaving the AC fully off between guests is not just expensive when the next group arrives — it can cause mold and warped wood. Cooling vacancy strategy is partly about money and partly about not destroying the house.

Where Cooling Money Disappears

Three patterns drive almost every inflated summer bill at a short-term rental.

Guests setting the thermostat to 65 and walking out. They are used to feeling cool air on their skin, set it low, and never bring it back up. The system runs nonstop until your next check-in. An automatic thermostat reset triggered the moment a guest checks out stops this leak cold.
Sun load nobody compensates for. West-facing rooms in summer can climb 10 degrees over the rest of the house in late afternoon. The thermostat in the cool hallway calls for AC even when the home is technically empty.
Doors propped open during turnover. Cleaners open everything to air the place out, then leave the AC running on full while doing it. You can lose hours of cooling against an open patio door.

A smart thermostat plus a clean vacant mode tuned for short-term rentals handles the first issue. A few cheap remote sensors balance the second. A simple cleaner instruction handles the third without any technology at all.

Recommended Gear and Vacancy Setpoints

Use the same gear most hosts already trust: an Ecobee Premium with included SmartSensors, a Nest Learning Thermostat (4th gen), or a Honeywell Home T9. The Ecobee Premium has a slight edge in hot climates because the room sensors let you average temperatures across rooms instead of cooling to the coldest spot. The Nest is the cleanest install for a single-zone forced-air AC, and the T9 wins if you have a sprawling layout with one west-facing master suite that always overheats.

For vacancy temperatures in cooling season, the rules of thumb that work across most properties:

Dry hot climates (desert, inland Texas): Vacant set to 82 to 85. The home recovers fast and there is no humidity penalty.
Humid hot climates (Florida, Gulf, low-country): Vacant set to 78 to 80, never higher. Going above 80 in humid air invites mold and that musty smell guests notice the second they walk in.
Mixed climates with mild summers (Pacific Northwest, mountain west): Vacant set to 80 or simply turn AC off if temps stay reasonable.

The mistake people make in humid climates is treating cooling like heating — raising the setpoint as high as possible to save money. A house held at 85 in Florida for three days will be a swamp inside, and your AC will run for 12 hours straight when you finally pre-cool it for the next guest. You also risk humidity damage to floors, doors, and electronics. Set 80 as a hard ceiling in humid zones.

Step-By-Step Cooling Vacancy Setup

In the Ecobee, Nest, or Honeywell Home app, build three modes: Guest (cool to 72), Vacant (cool to 80, or 82 in dry climates), Cleaning (cool to 74).
Set the default schedule to Vacant. Everything else is an override on top of this safety net.
Schedule a pre-arrival cool-down four to six hours before check-in. In dry climates four is enough. In humid Florida, give it six because pulling humidity out takes longer than dropping temperature. Most hosts wire this directly into their smart thermostat schedule between guests so it runs without thinking.
At checkout time, switch to Cleaning for two to three hours, then drop into Vacant. The cleanest way to wire this is via a thermostat automation after checkout that fires on your booking calendar.
Cap the guest-facing low setpoint at 70 or 71. There is no comfort difference between 68 and 71, but the energy difference is enormous.
If your thermostat tracks humidity, set a humidity ceiling of 60 percent. The system will run AC briefly to dehumidify even when the temperature is fine.

If you want to get fancier, add an inexpensive Aqara Door & Window Sensor or similar Zigbee contact sensor on the patio slider. If it stays open more than 10 minutes during a vacant period, your phone gets a ping. This catches the cleaner-left-it-open scenario before the AC has been wasting cycles for a full day. Hosts with multiple zones usually graduate to a full Airbnb HVAC automation routine that handles AC, fans, and humidity together.

What To Tell Guests

Frame the thermostat as comfort-first, with a soft mention of automation. In your house manual: “The home is set to 72 for your stay. You can adjust between 70 and 76 anytime. The system manages itself between bookings, so feel free to leave it where you like when you check out.”

Notice you do not say “please don’t set it below 70” because they cannot — the cap handles that for you. Telling guests not to do something usually invites them to try.

Common Mistakes That Eat Your Savings

Setting vacant temps too high in humid climates. The AC needs to cycle to pull moisture out. 78 to 80 is the sweet spot in Florida and the Gulf. Higher and you trade utility savings for mold remediation.
No pre-arrival cool-down. A house at 80 will not be at 72 in 30 minutes. Guests check in to a sweltering home and review accordingly.
Ignoring sun-load rooms. A west-facing bedroom can be 88 while the hallway thermostat happily reads 72. Use Ecobee SmartSensors or Honeywell T9 RoomSensors and average them.
Letting cleaners override. They turn the AC down to 65 to feel cooler while working hard, then forget. Either give them clear written rules or use an automation that resets the thermostat two hours after their scheduled departure.
Same-day turnover treated like a long gap. Do not drop into Vacant for a six-hour cleaning window. Go straight from Guest to Cleaning to Guest.

Host Checklist

Smart thermostat (Ecobee Premium, Nest Learning, or Honeywell T9) installed with app access.
Vacant cooling setpoint chosen by climate (78 to 85).
Guest range capped at 70 to 76.
Pre-arrival cool-down 4 to 6 hours before check-in.
Humidity ceiling set if your thermostat supports it.
Door sensor on the most-likely-left-open exterior door.
Cleaner instructions written in plain language.
House manual line about the thermostat for guests.

Frequently Asked Questions

How much can I save by automating cooling between guests?

Hot-climate hosts who switch to a vacancy setpoint of 78 to 80 typically see 15 to 25 percent off their summer cooling bills. The savings are larger if you have lots of midweek gaps and smaller if you book solidly. Either way, the thermostat usually pays for itself in one summer.

Why can’t I just turn the AC off completely between guests?

In dry climates you can, briefly. In humid climates you absolutely should not. With the AC fully off in Florida or coastal Texas, indoor humidity rises into the 70s within a day. That triggers musty smells, mold growth in closets, and damage to wood furniture. Holding 80 with humidity control is dramatically cheaper than fixing mold.

What temperature should I set when guests arrive?

72 is the sweet spot. Almost everyone is comfortable at 72, the AC does not have to work overtime, and you avoid the “why is it so cold in here” reaction at the front door. Adjust within the 70 to 76 range based on what your guests respond to in reviews.

Do I need a separate dehumidifier?

In most homes the AC handles humidity adequately if you set a humidity target and let it cycle. In a basement, slab home, or a property that sits vacant for long stretches in summer, a standalone dehumidifier on a smart plug (a Kasa KP125 or similar) is a smart addition. Set it to maintain 55 percent and let it run when the AC is in vacancy mode.

Will guests complain about the temperature cap?

Almost never if your cap is reasonable (70 or 71 minimum). The rare guest who tries to set it to 65 and finds they cannot will usually just leave it at 70 and forget. If anyone messages you about it, raise the cap remotely from the app for the duration of their stay. It is a one-tap fix.

Next Steps

Pick a thermostat, build the three modes, and run it for one full vacancy cycle before your peak summer week. The same setup that helps you save cooling costs at your Airbnb also handles winter, so you are buying it once for the whole year.