Nest has started selling a new device that's super affordable.
The new Temperature Sensor costs just $39, but it works with the company’s smart thermostats to keep individual rooms in your home at a certain temperature. It requires the latest Nest Learning Thermostat or the Nest Thermostat E (no other model is supported), and is designed to be placed on shelf or put on a wall. From there, you add it to your Nest system via the Nest app and pick a temperature.
So, if it's positioned in your bathroom, you can set the temperature to 75F degrees, and it'll ensure the room stays that warm. You can put multiple sensors around the house, too, and you can tell Nest which one to prioritise at a specific time of day. The only limitation is that they need to be within 50 feet of the Nest thermostat it’s linked with, and you can only pair six at a time with a Nest thermostat.
However, you can do grouping up to three times for a maximum of 18 sensors. From what we can tell, these are basic internet-connected devices that aren't as advanced as, say, the one from Ecobee that can smartly tell when you're in the room and then prioritise that room while you're in it. Still, it's cheap. Nest’s Temperature Sensor was announced back in March and preorders started shipping last month.