Leave the AC on, set around 78 to 82 degrees, and keep indoor humidity under 60 percent, the setting range and humidity target that Florida Power & Light (FPL), Jupiter’s electric utility, gives seasonal residents who leave for months. Not off, and not left to float. Of the two numbers, humidity is the one that tells you whether the setting is working.
If the system already struggles to keep up, get air conditioning service booked before the trip, not after it.
What Should a Jupiter, FL Snowbird Set the AC To While Away All Summer?
Around 78 to 82 degrees, FPL’s range for seasonal residents, with the system left running all summer and its breaker left on.
Where you land in the range depends on the house, and the house tells you through its humidity. Start in the middle, watch the reading once you’re gone, and bring the setting down if humidity climbs past FPL’s 60 percent target. A house that holds under it at the top of the range can stay there.
In Jupiter this is a common situation, not a rare one. About one in seven of the town’s housing units is counted as vacant for seasonal, recreational or occasional use, according to the U.S. Census Bureau’s American Community Survey estimates for 2020 to 2024, and for those houses the risk over a summer away is moisture.
The setting for a house you’re living in is a separate question, and our Palm Beach Gardens guide to summer thermostat settings covers it, along with why a setting pushed too high stops drying an empty house.
Why Is Humidity the Number to Watch in Empty Homes in Jupiter?
Because a temperature setting only tells the AC when to cool. It can’t tell whether the house is staying dry, and in an empty house through a South Florida summer, moisture is what does the damage.
Switched off, an empty house can’t be counted on to dry out. In vacant-home tests the Florida Solar Energy Center (FSEC) ran for FPL in three Brevard County houses, farther up Florida’s east coast, and published in 2005, indoor humidity averaged 62, 69 and 73 percent with no AC running, while outdoor humidity averaged about 77 percent from June through October. A very high setting didn’t solve it: in FSEC’s tests, 85 degrees gave generally poor results, and in some test periods at some houses neither 85 nor 83 made the AC run at all.
Mold and mildew grow when humidity stays high, say over 70 percent, for extended periods, by FSEC’s measure, so holding the house under FPL’s 60 percent target keeps it clear of that. Houses differ, too: in those tests, some needed more help than others to stay dry, and air leaking in from outside was a big part of why.
A steady setting isn’t the only way to get there, either. With a programmable thermostat, a short, cold run in the early morning can do the drying instead. FPL’s seasonal checklist puts it at 72 degrees for two hours each morning before the sun comes up and 88 the rest of the time, and FSEC’s report says an early-morning run at 74 degrees from 3 to 5 AM appears to work well in a majority of homes. Either way, the humidity reading is the judge.
Should the AC Setting Change From May to October for Jupiter Residents?
It may need to, and if it does, the milder months are the ones that need a lower setting than July, not a higher one. If the house sits empty from May to October, May and October themselves deserve the closest watching.
On a cooler, cloudier day the house may never warm up to a high setting, so the AC has little reason to come on. That is where high settings failed in FSEC’s tests: on cooler and cloudier days, little or no run time meant little or no moisture removal, and even 83 degrees did not give reliable humidity control during fall weather.
So check the reading more often at both ends of the season. If humidity climbs past the target while the temperature looks fine, bring the setting toward the bottom of the range, or add the early-morning cool-down if your thermostat is programmable. If you already use the cool-down, the morning setting may need to drop as well: for manufactured homes, FSEC’s report notes that a lower setting of say 70 or 72 degrees may be necessary in spring and fall.
How Can You Check a Jupiter House’s Humidity From Up North?
With a device that reports indoor humidity to your phone. A Wi-Fi thermostat whose app shows humidity as well as temperature will do it, and it lets you adjust the setting remotely, so every change above is a quick one. If yours can’t show humidity, a separate Wi-Fi humidity sensor does the same job.
Put a sensor where the air moves least, such as a closet or the bedroom farthest from the air handler, rather than beside the thermostat. If it can send alerts, set one at the target. Then read the trend, not a single reading:
- Under 60 percent: the setting is working, and you’re within EPA’s guidance on mold and moisture to keep indoor humidity below 60 percent if possible.
- In the 60s and rising: the setting is too high for the house right now. Bring it down and keep watching.
- Near 70 and staying there: that’s the level FSEC ties to mold and mildew. Lower the setting and have someone look in.
- No readings at all: the device may have lost power or internet, which is reason enough to send someone over.
A plain battery hygrometer works too, as long as someone is there to read it.
Who Can Safely Look In on the AC While the Owners Are Away in Jupiter?
Anyone you trust with a key: a neighbor, a friend, a property manager or a house-watch service. The visit is for looking, not fixing. FPL’s checklist for seasonal residents asks for someone to check on the property every two weeks while you’re away.
Set the limits before you hand over the list. Everything on it is done by looking, listening and smelling. Your visitor should not open the air handler or the outdoor unit, touch wiring, open the electrical panel, or climb into a hot attic to check equipment there. If anything looks wrong, the job is to call an AC company, not to restart or reset anything.
- The thermostat is still set to cool, at your setting, and the house feels close to that temperature.
- The humidity reading, if the thermostat or a sensor shows one, sent to you by text.
- No musty smell at the door, in closets, or in the rooms farthest from the air handler.
- No water on the floor around the indoor unit and no new stains on any ceiling.
- When air is blowing from the vents, the outdoor unit is running too.
- Interior doors still open, the way you left them.
Leave your visitor the number of an AC company that serves Jupiter, so a problem gets a call the day it’s found.
What Should an AC Technician Check Before a Jupiter Snowbird Leaves for Months?
That the system can still do the drying an empty house depends on: it makes properly cold air, the ducts aren’t pulling in humid air, the drain is clear and the filter is clean. Book a pre-departure maintenance visit early enough to fix whatever it turns up.
Cold air and tight ducts matter more than usual here, because the early-morning cool-down above assumes an AC that can produce cold supply air. Supply air can run warmer than normal because of an improper refrigerant charge, too much airflow, or large leaks in the return ducts, and leaky ducts can draw humid air into the house. If you plan to use the cool-down, have duct leaks found and repaired first.
The drain earns its place on the list too. On systems with a float switch, a clogged drain can shut the AC down to keep water off your floors and ceilings, and in an empty house that means no cooling and no drying until someone notices. Our Boca Raton guide to the signs of a clogged AC drain line explains how that switch works.
Two things are yours before you lock up. Leave the fan on AUTO, not ON: in a vacant home, AUTO avoids drawing humid air in through duct leaks and keeps the filter from fouling as quickly. And keep interior doors open so air can move through the whole house.
What if Humidity Still Climbs in a Closed-Up House in Jupiter?
Bring the setting toward the bottom of the range first, or add the early-morning cool-down. If the reading still won’t settle under the target, the house needs more drying than the AC alone is giving it, and a dehumidifier is the next step. In FSEC’s tests, a dehumidifier with a fan to move the air kept humidity under control in all three houses. Whether a whole-house unit makes sense for yours, and how one should be sized, is covered in our Boca Raton guide on whether a whole-house dehumidifier is worth it.
A sudden jump is different from a slow creep. If the reading was steady and then climbs fast, or the house is warmer than the setting, something may have stopped, such as a tripped float switch or a failed part. That’s a service call, not a settings change.
If you come home to a musty smell anyway, our West Palm Beach guide to why an AC smells musty walks through where it comes from. Once you’re back for the winter, the everyday habits that keep moisture down in a lived-in house are in our Delray Beach guide to lowering humidity.
The Final Word on a Jupiter, FL Snowbird’s Summer AC Setting
- Leave the AC on, around 78 to 82 degrees, FPL’s range for seasonal residents.
- Judge the setting by indoor humidity, and keep it under 60 percent, FPL’s target.
- Watch May and October, when cooler, cloudier days can leave a high setting idle. Bring it down or add the early-morning cool-down if humidity creeps up.
- Read the humidity from your phone, and have someone you trust look in, looking only.
- Before you leave, have a technician confirm cold air, tight ducts, a clear drain and a clean filter, then set the fan to AUTO and keep the interior doors open.
- If humidity still climbs, lower the setting first, then add a dehumidifier.
If you’d like the system checked before you head north, schedule a visit or start from our Jupiter service area page. We’re a locally owned company with over twenty years in South Florida.
