Learn about Cool to Dry

• If your air conditioner doesn’t have a dehumidification mode, Cool to Dry is off by default.
• If your air conditioner does have a dehumidification mode, Cool to Dry is turned on by default.
• You can turn Cool to Dry on or off on most thermostats or with the Google Home or Nest app.

On your thermostat

1. Press the ring to bring up the Quick View menu.
2. Select Settings.
3. Open Nest Sense.
4. Choose Cool to Dry.

Choose YES to enable Cool to Dry or NO to disable it.

Home app

1. Open the Home app .
2. Tap Favorites or Devices
3. Select the thermostat that you want to control.
4. Access your thermostat's humidity settings:
   • Nest Learning Thermostat (4th gen):
     Tap Settings Temperature preferencesHumidity HelperCool to Dry.
   • All other thermostats:
     Tap Settings Temperature preferencesCool to Dry.
5. Tap the switch to enable or disable Cool to Dry.

Nest app

1. Select your thermostat on the app home screen.
2. Tap Settings .
3. Tap Nest Sense Cool to Dry.
4. Turn Cool to Dry on or off.

Check the current humidity

• On your thermostat: Press your thermostat’s ring to open the Quick View menu. Here you can find your home’s current humidity.
• In the app: Tap your thermostat. You’ll find the current humidity.

On your thermostat

1. Press the ring to bring up the Quick View menu.
2. Open Settings.
3. Pick Equipment Continue Continue.
4. Select Dehumidifier Set Humidity.
5. Choose the approximate humidity level you want your thermostat to target.

Home app

1. Open the Home app .
2. Tap Favorites or Devices
3. Select the thermostat that you want to control.
4. Tap Settings Dehumidifier.
   • Tap the switch to enable the dehumidifier.
   • Tap the plus or minus buttons to set the approximate humidity level that you want.
5. For additional settings on Nest Learning Thermostat (4th gen) only, return to the Settings menu, and tap Temperature preferences Humidity Helper Advanced configuration to adjust:
   • Overcooling limit
   • Humidity threshold
   • Minimum indoor temperature

Nest app

1. On the home screen, select the thermostat you want to control.
2. Tap Settings .
3. Select Equipment Dehumidifier.
4. Slide the button to set the approximate humidity level you want.
5. Tap the switch in the upper right to turn humidity control on or off.

How settings work

• To set an exact humidity percentage for your Nest thermostat to try to maintain, you need to have a standalone dehumidifier set up in your thermostat.
• Cool to Dry will only cool your home to 3°F below your current set temperature when you're home. This means Cool to Dry may not always reach a specific humidity level before it has to shut off.
• Because Cool to Dry may not always reach your target humidity, you’ll only be able to set an approximate target humidity level, represented by the number of water drops on your thermostat. That’s why you won’t find a specific percentage in your humidity settings.
• To set your humidity level, you can select from 0 to 3 shaded water drops on your thermostat as your target humidity level to represent approximate humidity in your home. To turn humidity control off, select the empty water drop.
• If you select a low humidity level (fewer water drops) your system may need to run more frequently to keep your humidity low, which may use more energy.
• If you choose a high humidity level (more water drops) your system should run less often.

Follow these steps to check your system's wiring, and then check the thermostat's star terminal or AQ+ terminal (depending on your thermostat and your system) to find out if your cooling system has a dehumidification mode.

On your Nest thermostat

1. Press your thermostat's ring to open the Quick View menu.
2. Choose Settings Equipment.

Home app

1. Open the Home app .
2. Tap Favorites or Devices .
3. Select the thermostat that you want to control.
4. Tap Settings Thermostat Wiring.

Nest app

1. Select the thermostat you'd like to check on the home screen.
2. Tap Settings .
3. Choose Equipment Wiring.

If there isn't a wire in the star connector or AQ+ terminal

Your air conditioner doesn't have a dehumidification mode.

If there is a wire in the star connector or AQ+ terminal, check the wire label.

• If the wire doesn't say dehum
  Your system doesn't have a dehumidification mode.
• If the wire says dehum
  Your system has a dehumidification mode or a standalone dehumidifier.

If you have a standalone dehumidifier, you won't find Cool to Dry in the settings. Your Nest thermostat will use your dehumidifier instead of Cool to Dry to help control the humidity in your home.

Check your system's manual or ask a pro

If you still need help determining if your air conditioner or heat pump has a dehumidification mode, check your system's model number on the manufacturer's website, or check the manual. A local professional installer can also determine if your system has a dehumidification mode.

If you don't have a dehumidification mode on your air conditioner, you can still use Cool to Dry. Since your air conditioner converts hot humid air into cold dry air, Cool to Dry takes advantage of this and cycles the air conditioner on and off to lower the humidity.

When the Nest thermostat senses very high humidity, Cool to Dry automatically turns on the air conditioner. When Cool to Dry is on, your system may cool your home to a temperature lower than what you've set your thermostat to (up to 3°F lower than your scheduled temperature).

Cool to Dry without a dehumidification mode can be expensive

If you use Cool to Dry with an air conditioner that doesn't have its own dehumidification mode, your air conditioner will run more often than usual, which can be expensive. If your air conditioner doesn't have a dehumidification mode, you should only use Cool to Dry if you live in a very humid climate.

If you already use your air conditioner to lower the humidity in your home by running it non stop, Cool to Dry can help you save money. Instead of keeping the air conditioner on all the time, Cool to Dry will cycle your air conditioner on and off while you're away, turning it on only when your humidity levels rise.