What should I set my AC to when I leave New Orleans for a week?

For a vacant one-week trip, keep the cooling system on. Florida Power & Light recommends 80°F for a few days and 82°F for trips lasting weeks, so 80°F to 82°F is a Florida-utility starting range to test, not a setting proven for a New Orleans house. Lower the setting if indoor relative humidity stays above 60%. See FPL’s vacation guidance and EPA’s moisture-control limit.

Do not use that range when people, pets, medicine, instruments, plants, art, or other temperature-sensitive items remain. Their requirements control the setting.

Test the plan before you leave

Choose the proposed setting while you are still home and can respond. Follow a separate humidity meter’s placement instructions and put it in a representative living area. Record temperature and relative humidity through warm, rainy, and overnight periods if the weather allows.

Use the humidity trend to decide whether the setting works. EPA recommends keeping indoor relative humidity below 60%, with 30% to 50% ideal when practical for moisture control. See its indoor-air guidance and mold guide.

An empty house can need little temperature cooling while moisture still enters from outdoor air, damp material, plumbing, or the building. DOE describes that sensible-versus-moisture problem in its hot-humid research. Turning cooling off removes the AC’s ordinary moisture-removal cycle.

If the test stays above 60% RH, lower the setting and test again. Persistent moisture may need an HVAC or building-moisture diagnosis. A dehumidifier is not an automatic answer because drains, ducts, controls, water sources, and equipment condition may be involved.

Set the controls you actually have

Use COOL and the normal AUTO fan setting for an ordinary central system. Continuous fan operation can return some coil moisture to the air on some systems. Trane gives the AUTO recommendation for humid conditions in its owner’s guide on page 3. A designed ventilation or dehumidification system may use different controls, so check its manual before changing them.

Program the vacation hold, start time, end time, and return setting. Confirm them on the thermostat itself. “Eco,” “Away,” and “Vacation” behavior varies by product and generation. Google’s Nest guidance shows why an automatic Eco setting and a long hold are separate behaviors on that product.

Remote sensors and alerts are useful only while the sensor, equipment, power, internet, and app are working. Test the alert and decide who can enter the house if it fires.

Check the parts that can defeat the plan

Inspect the filter and replace it according to the equipment instructions. Look for water around the indoor unit or drain. Do not open a cabinet or clear a drain without a model-specific procedure.

Outside, remove loose objects or vegetation that are already touching the unit without disassembling it. Keep exterior doors and windows closed. Turn off ceiling fans in empty rooms; fans move air but do not remove heat or water from the house.

ENERGY STAR places filter checks with the homeowner and coil, refrigerant, airflow, and condensate inspection with a contractor in its maintenance checklist.

If the system smells burned or has repeatedly tripped a breaker, leave it off rather than letting it restart while the house is empty. Resolve visible ice or active leaking before departure.

Make a failure plan

A smart thermostat cannot cool the house during a power outage. Write down the local contact who can enter, the alert that should trigger a visit, and the HVAC contact information. Give that person only the access information they need through a secure channel.

NOLA Ready’s power-outage guidance explains current outage preparation. Do not rely on an outage map alone to prove that power reached a particular unit.

For a rental, tell the tenant or property contact what setting should remain, who is allowed to change it, and how to report water or lost cooling. Renters should report an equipment problem rather than opening or altering the system.

Why one temperature cannot cover every house

University of Florida IFAS advises leaving seasonal homes no higher than 85°F and planning for moisture control in its hot-humid closing guide. Trane and utility guidance use other ranges. These numbers are starting guidance, not a New Orleans guarantee.

Test the actual house because air leakage, duct location, controls, shade, and water sources can change the result.

Before locking the door, save the temperature and humidity trend, confirm the hold and alert, check for water, and make sure a real person can respond. That plan matters more than choosing the most popular number from a search result.

Test the plan before you leave

Set the controls you actually have

Check the parts that can defeat the plan

Make a failure plan

Why one temperature cannot cover every house

Sources

Related answers