Dry Mode vs Cool Mode: Which AC Setting Should You Use?

Cool mode lowers the room's temperature and removes some moisture as it runs. Dry mode does the reverse: it removes moisture first and cools only lightly, with the fan held at a low speed. Use Cool when the room is too hot, and Dry when the temperature is fine but the air feels damp and sticky.

Dry mode vs cool mode at a glance

The table sums up what the makers' own manuals and support pages say. The details differ by brand, so the sections below quote each one.

What cool mode does

Cool mode is the standard setting for making a room colder. Daikin Malaysia's guide to cool, dry and fan modes says it uses both the compressor and the fan. Senville's mode guide says Cool "removes heat (and some humidity) to cool the room."

You choose the temperature and, on most units, the fan speed. GE's portable air conditioner manual explains that the compressor cycles on and off to keep the room at the level you set. ENERGY STAR's room air conditioner page adds that a conventional compressor is either on at full capacity or off, while units with a variable-speed compressor adjust their speed to hold the temperature steadily.

We cover the setting in more depth in our guide to cool mode on an AC.

What dry mode does

Dry mode is built to take water out of the air. LG says its dehumidification operation removes moisture "while maintaining a low cooling level," and the outdoor unit still runs, so you may feel some cool air. Senville says Dry runs at low fan speed with little change in temperature. GE calls it dehumidification only.

The low fan is the key difference. ENERGY STAR's own advice for humid days is to set the fan low, because slower air movement removes more moisture. In Dry mode the unit does that for you, and most models will not let you change it. MrCool's remote manual says the fan speed is controlled automatically in Dry mode, and GE and Pioneer say the same.

Midea's guide to dry mode (in Spanish) describes the compressor switching on and off intermittently and the fan running at a fixed low speed. It contrasts that with Cool mode, where the fan speed varies and the compressor runs continuously until the room is cool.

For the full picture, see our explainer on dry mode on an AC.

Which one should you use?

Ask one question: is the problem heat or dampness?

Use cool mode when

• The room is warmer than you want it.
• It is a hot afternoon or a heat wave.
• You are bringing down a house that heated up while you were out.

Daikin Malaysia says to use Cool when both the temperature and the humidity are high. Pioneer says dry mode becomes less efficient the hotter it gets outside, which points the same way.

Use dry mode when

• The temperature is fine but the air feels heavy or clammy.
• It is raining or humid, but not hot.
• You notice a musty smell or condensation on the windows.

Daikin Malaysia's rule is to use Dry when the temperature is acceptable but the humidity is too high. Pioneer describes dry mode as designed for when it is damp or wet but not very warm. The EPA's mold and moisture guide lists condensation as a sign of high humidity and suggests keeping indoor humidity below 60 percent, ideally between 30 and 50 percent.

When neither is the answer

If both temperature and humidity are comfortable and you only want moving air, fan mode runs the fan with the compressor off. Daikin says it changes neither temperature nor humidity, and Senville says it uses the least energy of the modes. Our guide to every AC mode and remote symbol covers the rest.

If a space stays damp no matter what, such as a basement with seepage, a dehumidifier is the right tool. Pioneer says dry mode is not meant to replace one, and ENERGY STAR's dehumidifier guide sizes units for very damp and wet spaces by pints of water per day.

Why cool mode sometimes leaves a room clammy

Cool mode removes moisture only while the compressor runs and the coil is cold. ENERGY STAR explains what goes wrong with an air conditioner that is too big for the room: it cools the room before it has a chance to remove the humidity, which leaves the air cool, moist and clammy. A properly sized unit runs long enough to do both. Our room size calculator shows what capacity your room needs.

If your room hits the set temperature but still feels sticky, that is the case for trying Dry mode, or a lower fan speed in Cool mode, as ENERGY STAR suggests.

Which mode uses less energy?

There is no ENERGY STAR or Department of Energy figure comparing the two, and the makers disagree:

• Midea's comparison lists dry mode as using less energy and claims savings of up to 20 to 30% versus Cool in humid, mild weather. That is Midea's own claim, with no test published alongside it.
• Daikin Spain describes its dry mode as working with low energy consumption.
• Pioneer's dry mode guide says the setting consumes more energy and is less efficient than other modes.

For Cool mode, Daikin Malaysia notes that the energy used depends on how far you are bringing the temperature down: cooling a room from 30°C to 25°C takes less energy than cooling it from 35°C to 25°C. ENERGY STAR's savings tip applies to both modes: set the thermostat as high as is comfortable, typically 78°F. To see what your unit costs per hour at your local rate, use our cost to run calculator.