Airwave is a feature available on Google Nest thermostats that can help lower air conditioning costs by automatically shutting off the compressor at the right time. Airwave turns on automatically when the humidity level inside your home falls below a certain level, which is calculated by Nest to be optimal for your home. When Airwave activates, an icon will appear on your thermostats display, which is a blue swirl on the Nest Learning Thermostat and the Nest Thermostat E, and three wavy lines on the Nest Thermostat. While Airwave requires the humidity level inside your home to be relatively low, it may still turn on if its humid outside. If its very humid in your home, your Nest thermostat wont use Airwave and will run your systems compressor for the entire cooling cycle to prioritize lowering the humidity and helping to prevent mold. You can turn Airwave off or on with your Nest thermostat or with the app. With the Home app, you can tap your devices tile, tap Settings, open Temperature Preferences, select Airwave, and tap the switch to turn Airwave off or on. With the Nest app, you can tap Settings, select your thermostat, tap Airwave, and turn Airwave off or on. Airwave can save energy and money by using the cooling off period that happens after the compressor shuts down to squeeze a few extra cold blasts out of your A/C by keeping the fan running.