Mini Split Dry Mode
Mini split dry mode is the setting with the water drop icon on the remote, and a lot of people never touch it because they aren't sure what it does. In short, it will run the system to pull moisture out of the air instead of hitting a temperature.
What dry mode actually does
In dry mode the indoor fan will slow down and the compressor will run at a low speed. Air is moving slowly over the cold indoor coil, so more of the moisture in it condenses on the coil and goes out the drain line. The unit still cools a little while it does this, but it is not trying to hit your set temperature the way cool mode is. Some brands will let you set a target temperature in dry mode and some won't, so you might want to check your manual.
When to use it
Dry mode is best on days that are muggy but not really hot. Think spring and fall, a rainy week or a basement that feels damp. On those days cool mode can reach the set temperature quickly and shut down before it removes much moisture, which leaves the room cool but clammy. Dry mode keeps the coil cold longer and gets more water out.
On a hot summer afternoon, just use cool mode. It removes moisture too, and it will keep the room comfortable. Dry mode on its own may not keep up when the heat load is high.
Dry mode vs a dehumidifier
A portable dehumidifier puts the heat it pulls out back into the room, so it can run no matter how cool the room already is. A mini split in dry mode is still cooling, so in a room that is already cool it will make it colder, and many units stop or slow way down once the room gets near their lower limit. If you have a space that is cold and damp at the same time, like a basement in winter, a dehumidifier is the better tool.
Does dry mode save energy?
It usually uses less power than cool mode at any given moment, since the compressor and fan are running slow. But it is doing a different job, so it isn't really a swap for cool mode on a hot day. The place where it saves money is on those mild humid days, and on those days you might otherwise run cool mode at a low setpoint to feel comfortable.
A few tips
- Keep the filters clean. With a dirty filter, the airflow gets cut and dry mode becomes less effective. Our guide on how to clean mini split filters walks through it.
- Make sure the condensate drain is flowing. Dry mode sends a lot of water down the line, and a clog will show up fast as a drip from the indoor unit.
- Close windows and doors while it runs, or it's drying the outdoors.