Earlier this year, Nest finally made it possible to balance the HVAC system for different areas of your home without using multiple thermostats. The Temperature Sensor, a small wireless puck you can place throughout your home, lets the Nest system set its programming to the temperature of a specific room instead of just where the thermostat is mounted. The Temperature Sensor works with the third-generation Nest Learning Thermostat and the Nest Thermostat E, and can be purchased for $39 or in packs of three for $99.
In many ways, the Temperature Sensor catches Nest up to its competitor Ecobee, which has included remote sensors with its smart thermostats for years. It also makes balancing hot and cold areas in your home much easier than using just a single Nest thermostat on the wall. If you are constantly adjusting the temperature setting of your thermostat throughout the day to compensate for where you are in your home at a given time, the remote sensors eliminate the need for that. But as I’ve found out testing the Temperature Sensor in my home this summer, the whole experience could be improved significantly.
Setting up the Temperature Sensor is as simple as pulling the battery tab on the back of the puck, and adding the device in the Nest app. The sensor uses Bluetooth to communicate with the main thermostat, and it has a replaceable lithium battery that lasts up to two years, according to Nest. There’s a peg hole on the back of the sensor so you can mount it to a wall, but you can also put it on a shelf and it will work just the same.
Within the Nest app, you can name the sensor for whatever room you’re putting it in and then tell the system what times you want it to set itself to the sensor’s readings. This is the first major limitation of the Temperature Sensor: the times that you can program the thermostat to a sensor are limited to four time blocks: morning (7AM to 11AM), midday (11AM to 4PM), evening (4PM to 9PM), and night (9PM to 7AM). Those blocks are inflexible, so if you wake up earlier than 7AM or retire to your bedroom before 9PM, you can’t adjust them. I’d have loved to program the morning block to later in the AM, as my kitchen, which is on the main floor, is much cooler than the top floor of my house, where my family spends half the morning getting ready for the day. As a result, I frequently have to go in to the Nest app and override the programmed setting for which sensor it should read off of.
Further, the Temperature Sensor settings are locked to those time blocks — Nest did not include any sort of presence detection on the device. Unlike Ecobee’s remote sensors, Nest’s cannot tell when someone is present in the room and automatically adjust the system based on where you actually are in the house. The Nest Protect smoke alarms do have presence detection, which help the thermostat set its home and away modes automatically, but they do not measure temperature nor can they be used to inform the remote Temperature Sensor’s programming. Also, they cost $99 each.
The Nest will also only set itself based on a single reading at any given time. It cannot average the system based on all of the various sensors, which the Ecobee can do.
The Temperature Sensor is also limited to just measuring the temperature of the room. It cannot measure humidity or air quality, both of which are things that can vary greatly across a multi-story house. The Nest thermostats do measure humidity, but they cannot measure air quality, either.
Mostly, it feels like Nest did the bare minimum it could to satisfy customers asking for remote temperature sensors. Yes, the Temperature Sensor does improve the Nest Thermostat’s performance in my home, where temperatures can swing wildly from the bottom floor to the top floor. But the sensors aren’t cheap (unlike Nest, Ecobee includes a remote sensor with its thermostat), especially for how simple and limited they are, and the whole experience just gives me the impression it could be a whole lot smarter and easier to use with just a couple of tweaks.
Photography by Dan Seifert / The Verge
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