Closed-Up Homes: How to Keep a Vacation Home or Empty House Fresh

Quick answer: Keep the AC running at a warm setting instead of off, hold indoor humidity at 50% or below, refill the drain traps before you leave and when you return, and leave interior doors open so air can move. Then run a short checklist when you walk back in.

Why does a closed-up house go stale?

When nobody is home, air stops moving. Doors stay shut, fans stay off, drains go unused and the AC may barely run. In Central Texas, where summer humidity rarely lets up, a closed house can slowly gain moisture and odors while you're away.

It happens most often to:

• Families gone for a few weeks of summer travel
• Second homes and lake houses on Lake Travis, in Lakeway or out toward Marble Falls
• Homes of loved ones who have moved into care, or estates waiting to be settled
• Vacant homes on the market, or rentals between tenants

What should the thermostat be set to while you're away?

Around 80 to 82 degrees in the cooling season, not off. The biggest mistake is turning the AC off completely during warm months. Without cooling, indoor temperature and humidity climb, and everything from sofas to closets can take on that damp, closed-up smell.

• Set the thermostat to around 80 to 82 degrees in the cooling season. That's warm enough to save energy and cool enough for the AC to run and pull moisture out of the air. If humidity still creeps above 50%, lower it to 78.
• Keep indoor humidity at 50% or below. If your thermostat has a dehumidify setting, turn it on. If you have a whole-home dehumidifier, set it to 50%.
• Set the fan to "auto," not "on." A fan that runs nonstop can blow moisture from the coil back into the house. Our HVAC fan settings guide explains why.
• In winter, keep the heat around 55 to 60 degrees so the pipes don't freeze.
• Put in a fresh HVAC filter so the system runs clean while you're gone.
• Consider a smart thermostat or a remote humidity sensor so you can check on the house from your phone.

For a lake house that sits closed for weeks between visits, a whole-home dehumidifier keeps holding 50% with nobody there to check the hygrometer. Gold Eagle Services installs them and can service the HVAC before a long absence.

Why run water in the drains before you leave?

To keep sewer gas out. Every sink, tub, shower and floor drain has a trap, a U-shaped bend that holds water. That water blocks sewer gas from coming up the drain. Over a few weeks, especially in a warm house, the water evaporates.

• Before you leave, run water in every drain for a few seconds, including guest baths and the laundry floor drain.
• For long absences, a spoonful of mineral oil on top of the water in rarely used traps slows evaporation.
• Ask a neighbor or house sitter to run the taps and flush toilets every couple of weeks.
• When you return, run every drain first thing.

Our drains and dry traps guide covers this in more detail.

What else should you do before you go?

• Empty the fridge of anything that can spoil, and take out the trash.
• Leave interior doors open, including closets, so air can move through the whole house.
• Dry the washer and leave its door open.
• Shut off the water main if you'll be gone for weeks. Turn off the fridge's ice maker first, and ask your plumber if you're unsure.
• Unplug small appliances and close blinds on sunny windows to cut heat gain.

Your return-home checklist

When you walk back in, take 20 minutes to bring the house back:

1. Notice the first smell. A musty odor usually points to humidity. A sewer smell points to a dry trap.
2. Check the thermostat and hygrometer. Humidity over 60% means the house needs help drying out.
3. Run water in every drain and flush every toilet.
4. Open windows for 15 to 30 minutes if it's a dry, low-pollen day. Skip this in cedar season or on muggy days.
5. Run bathroom and kitchen exhaust fans for half an hour to move stale air out.
6. Look under sinks, around the water heater and near the AC drain for drips or stains.
7. Change the HVAC filter if the house sat for more than a couple of months.
8. Wash bedding and towels that sat in closed closets.

If you find a leak or visible growth, that's a different job. Call a plumber for the leak, and have an independent state-licensed professional look at any growth before anyone treats the house. Measuring or analyzing indoor air is their work, not ours.

When is a closed house worth a whole-home treatment?

A warm thermostat setting and mineral oil in the traps slow the staleness down. They don't undo a whole summer of it. A whole-home dry fog treatment is worth a look when:

• A second home or lake house has sat closed through a hot, humid summer and smells stale every time you arrive
• An estate home has been closed for months and family members are preparing to move in, rent or sell
• A home is going on the market and you want it to feel and smell fresh for showings
• You're moving into a home that sat empty before closing

If one of those sounds like your house, we can help. Our whole-home dry fog treatment, with the patented Pure Maintenance VaPURE system, sends a fog through every room, the closets you left open and the HVAC ductwork without getting things wet, and helps control the growth of odor-causing microorganisms on hard, non-porous surfaces. It takes one day, so it can be done the day before you arrive. Learn more about bio-load in what is your home's bio-load.

Get a free phone consultation

Pure Maintenance Austin, brought to you by Gold Eagle Services, serves all of Central Texas, including College Station, Round Rock, Georgetown, San Marcos, Bastrop and Marble Falls. Book a free phone consultation: a Comfort Advisor calls you, learns about the house and sends a written quote based on square footage. Call 512-904-4646 or email IAQ@goldeagleservices.com. We're open Monday through Saturday, 7am to 7pm.