Humidity Is the Real Enemy: How to Get Your Louisiana Home Comfortable (Not Just Cold)

You set the thermostat to 74. The house reads 74. And you still feel sticky, the sheets feel damp, and there's a faint musty smell in the hall closet. Sound familiar? In South Louisiana, temperature is only half the comfort story. The other half — and often the bigger half — is humidity.

Here's what's actually going on, what humidity level to aim for, and the fixes that work in New Orleans homes, from Uptown shotguns to slab houses in Kenner to everything in between.

Sensible heat vs. latent heat, in plain English

Your air conditioner does two jobs at once. Sensible cooling is lowering the temperature you read on a thermometer. Latent cooling is removing moisture from the air. Both take energy, and both count toward what your system can handle.

Here's how the moisture part works. As warm, humid air passes over the AC's cold indoor coil, it cools below its dew point and water condenses on the coil. That water drips into a pan and runs out the drain line — which is why your AC produces gallons of water on a muggy day (and why clogged drains are such a common problem here; see our drain line guide).

In a dry climate, nearly all of an AC's effort goes to lowering the temperature. Here, summer dew points regularly sit in the 70s, and a big share of the work goes to wringing water out of the air. A system that's sized, set up, or maintained poorly can hit the temperature target while barely touching the humidity.

That matters because humid air feels warmer. At high humidity, sweat doesn't evaporate off your skin as well, so 75°F at 65% humidity feels worse than 77°F at 45%. Get the moisture under control and most people are comfortable at a higher setpoint — which is easier on your Entergy bill too.

What indoor humidity should you aim for?

For a Louisiana summer, aim for 40–50% relative humidity indoors, and keep it under 60%. When indoor humidity stays above 60% for long stretches, mold, mildew, and dust mites thrive. Don't stress about getting much below 40% in July — it's rare here with air conditioning alone, and it isn't necessary.

The cheap hygrometer test

You can't fix what you don't measure, and most thermostats don't show humidity. Pick up an inexpensive digital hygrometer at any hardware store. Put it in your main living area, away from the kitchen, bathrooms, and supply vents, and let it settle for a day. Check it in the morning, in the late afternoon, and after the AC has been running a while. If you can, put a second one in a bedroom or a closet that tends to smell musty.

Inexpensive hygrometers can be off by a few points, so watch the trend rather than chasing one exact number. If you're consistently reading above 60% with the AC running, something needs attention.

Set the fan to AUTO, not ON

This is the easiest fix in this article. When your thermostat fan is set to ON, the blower keeps running after the cooling cycle ends. That pushes air across a wet coil and evaporates the water you just removed right back into the house before it can drain away.

Set the fan to AUTO so it runs only when the system is cooling. If you want more air movement, use ceiling fans. (Some newer systems have special dehumidification fan settings, but for most homes, AUTO is the right answer.)

Why oversized systems leave the house cool but clammy

Dehumidifying takes time. The coil has to get cold and stay cold for several minutes before water starts dripping off it steadily. An oversized system cools the air so quickly that it hits the setpoint and shuts off before it gets there. The moisture sitting on the coil evaporates back into the house, and you're left with air that's cool but damp.

This is called short-cycling, and it's hard on equipment too — the start-up is the most stressful moment for a compressor. It's common when a system was sized by a square-footage rule of thumb, or when someone upsized “to be safe.” A proper load calculation (Manual J is the industry standard) accounts for insulation, windows, sun exposure, duct location, and how tight the house is. We do one on every AC installation.

Signs your system may be oversized

• It runs in short bursts — just a few minutes — several times an hour, even on hot afternoons
• The temperature drops fast, but the house still feels sticky
• Some rooms are cold while others feel stuffy
• Indoor humidity stays above 55–60% even though the thermostat is satisfied

Equipment and settings that handle humidity better

Two-stage and variable-speed systems

Instead of blasting at full power and shutting off, two-stage and variable-speed systems spend most of their time on a lower setting. That means longer, gentler cycles, a coil that stays cold longer, and more moisture pulled out of the air. They also hold steadier temperatures and run quieter. In our climate, the comfort difference is real.

Dehumidify settings on thermostats and air handlers

Many modern thermostats and variable-speed air handlers have a dehumidify setting that slows the blower when humidity is high, so the coil stays colder and removes more water. Some can also let the temperature dip a degree or two below setpoint to keep pulling moisture. These features only work if your equipment supports them and the thermostat is wired correctly — something we check during a thermostat installation.

Ductless mini-splits and dry mode

Inverter-driven mini-splits ramp up and down instead of switching on and off, which helps with moisture, and many have a dedicated dry mode. They're a good fit for camelback additions, converted attics, sunrooms, and garages that the main system never quite reaches. Learn more about ductless mini-splits.

Whole-home dehumidifiers

A whole-home dehumidifier ties into your ductwork and runs on its own humidistat, removing moisture without overcooling the house. It's especially useful on those mild, rainy spring and fall days — 72°F and drizzling — when the AC barely runs but the house feels damp. It drains automatically, so there's no bucket to empty, and unlike portable units, it isn't sitting in the corner adding heat and noise. It's part of our indoor air quality services.

Hidden moisture sources in New Orleans homes

Leaky attic ductwork

In many local homes, the air handler and ducts live in an attic that reaches 130–150°F in summer — and that air is loaded with moisture. Leaky return ducts suck that hot, humid attic air straight into your system. Leaky supply ducts push cooled air into the attic, which leaves the house at slightly negative pressure and pulls humid outdoor air in through every gap around doors, windows, and outlets. Disconnected or crushed flex duct is something we find all the time.

In raised homes, ducts often run under the house instead, where humid air can make them sweat and drip. Either way, sealing leaks with mastic, reconnecting loose runs, and fixing damaged insulation can make a noticeable difference in comfort and humidity.

Bathroom and kitchen exhaust

Showers and cooking add a lot of water to the air. Run the bath fan during your shower and for about 20 minutes after. Make sure it actually vents outdoors — we regularly find bath fans that dump straight into the attic. Use a range hood that vents outside when you cook, and make sure the dryer vent is connected and clear.

The house itself

Older homes — shotguns, raised cottages, camelbacks — tend to leak air around windows, doors, baseboards, and floorboards. Every leak lets humid air in. Weatherstripping and sealing obvious gaps help. Outside, gutters that dump water against the foundation, standing water under a raised house, and dense plantings against the walls all add to the moisture load.

Signs you have a moisture problem

Symptom → likely cause → fix

A regular tune-up keeps the coil clean and the refrigerant charge right, both of which affect how much moisture your system removes. If your system is struggling with heat as well as humidity, our heat wave guide covers what's normal on the hottest days.