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Ecobee Smart Sensor vs Room Sensor: What’s the Difference Between Them?

Ecobee SmartSensor and Room Sensor

Smart thermostats have become a staple among smart homes as a money saving device, as well as a real convenience if you forgot to set the temperature before leaving the house. Smart thermostats have been on the market for a number of years now, and continue to improve over time. The sensors that accompany them have been improving as well. Ecobee is a leading brand in this area, and is consistently ranked on top as one of the best smart thermostats.

What Is the Difference Between Ecobee Smart Sensor and Room Sensor? The Ecobee SmartSensor is the second-generation sensor replacing the Ecobee Room Sensor. The most notable differences of the SmartSensor from the Room Sensor are its more elegant redesigned appearance, extended battery life, wider viewing angle, and the range it can be placed from the Ecobee thermostat.

Ecobee’s sensors are a big reason that it is one of the most successful, and useful, smart thermostats. In fact, Google’s Nest thermostat recently started using sensors as well, after seeing Ecobee’s success. There is a lot of valuable information that these little devices pass on to the smart thermostat. Let’s dig in a little more as to what that information is, and how the two types of Ecobee sensors differ.

What Do Ecobee Sensors Do?

First, I want to make sure we are all on the same page, and have a general idea of what a smart sensor does.

What is an Ecobee Smart Sensor? The Ecobee SmartSensor is an accessory device that can be paired with the Ecobee Smart Thermostat. The sensor detects movement in an individual room, as well as the temperature in that rom. This information is communicated back to the smart thermostat, which can set the temperature in a given room to your personal preference.

The Ecobee SmartSensors are designed to be placed in rooms other than the room where the smart thermostat is located. The Ecobee 3 Lite Smart Thermostat does not have a occupancy sensor built into it. In this case, you may want to use a SmartSensor or a Room Sensor in the same room as the thermostat.

The older Ecobee room sensors have the same role and functionality as the newer Ecobee SmartSensors, but the newer sensor is better at those roles.

What does Ecobee room sensor do? The first generation Ecobee room sensors detect both temperature and room occupancy. The Ecobee room sensor is an accessory device that can be paired with the Ecobee Smart Thermostat. They are designed to help regulate temperature in other rooms than where the thermostat is located.

The new Ecobee smart thermostats that are sold with the SmartSensor are backwards compatible with the first-generation room sensors, so there’s no need to worry about having to buy a whole bunch of new sensors if you are satisfied with your current ones.

That does lead us to the primary question though.

The Difference Between the Ecobee Smart Sensor and Room Sensor

According to Ecobee, the second-generation sensor, deemed the SmartSensor, is a completely new design starting from scratch. I find that hard to believe, as many of that technical specifications are too similar, which you will see in just a minute. First, I want to give an easy to compare table for the differences

Ecobee SmartSensorEcobee Room Sensor
Enhanced occupancy sensor with “Pet Immunity”No “Pet Imunity”
60 ft. Range from Thermostat45 ft. Range from Thermostat
Viewing angle: 140° horizontal and 100° vertical.Viewing angle: 120° horizontal and 25–30° vertical.
Occupancy sensor range: 20 ft.Occupancy sensor range: not specified
5 Year Battery Life1 Year Battery Life
Pair Using Ecobee AppPairing Requires Going to the Thermostat
New Rounded Design with Metal BaseMore Square Design
Ecobee SmartSensor vs Ecobee Room Sensor

Okay, now let’s get into the details of what each of those differences mean.

Enhanced Occupancy with Pet Immunity

Ecobee describes “pet immunity” as a feature that will “prevent false occupancy readings triggered by our furry friends.

They then go on to mention recommended placement for the sensor:

SmartSensor has undergone rigorous testing for “pet immunity” so you don’t have to worry about your furry friend or friends accidentally setting off its occupancy detection feature.

Here are a few extra steps you can take to further prevent your pets from setting off the occupancy detection feature:

Place the SmartSensor in a spot that is not within view of a stairwell—especially if your pet likes to race up and down the stairs all day.

Avoid placing the SmartSensor in front of that popular hangout spot for your pet, like their favourite chair.

If your pet is the curious type, consider mounting SmartSensor on the wall with the included wall-mount at a height of 6.5 ft (2 m), rather than placing it on a stand where it may be more easily knocked away.

Ecobee Support Page

These recommendations indicate to me that it is still a work in progress, and not really a “pet immunity.” From my engineering background, I know that this can be a difficult challenge. They are trying to differentiate between a pet and a human based solely on the infrared heat being transmitted from the body.

Secondly, I have to admit that I haven’t personally tested this pet immunity feature. I have my SmartSensor in a location that my pets never go. Also, my two dogs are only inside when I’m inside. Unless they find a way to break in while I’m gone.

Ecobee Sensor Communication Range

The SmartSensor can communicate with the thermostat to a range of 60 ft, were as the Room Sensor can only communicate up to 45 ft.

I don’t have 60 feet of open space in my house, and anything that gets in the way lowers the range.

Ecobee briefly mentions this: “Barriers and obstacles such as thick walls or different floors, and other devices operating on the same 915MHz frequency, such as a baby monitor, cordless phones, etc., may lower range”

Even though I don’t have 60 feet of open space, I have noticed a difference. My thermostat is located in the living room, and I have a sensor located in my bedroom. My bedroom is located directly off of the living room.

When the Room Sensor is placed on the far side of my bedroom, I will often get the “unable to communicate” error message. Moving the Room Sensor to the wall closer to the thermostat fixes this issue. With the SmartSensor, I am able to place it anywhere in my room without any trouble.

Ecobee Sensor Viewing Angle

I really don’t have the tools to measure this accurately, so I will take Ecobee at their word. Here is the information they provide. They do not provide occupancy viewing distance specs for the Room Sensor.

Ecobee SmartSensor Viewing Angle

Viewing angle: 140° horizontal and 100° vertical. Occupancy sensor accurate to a distance of 20 feet (6 m).

    For optimal placement for pet immunity, wall-mount at a height of 6.5 ft (2 m).

    For optimal placement for temperature readings, set at a height of 4 ft (1.2 m).

Occupancy viewing distance: 20 ft (6 m).


Ecobee Room Sensor Viewing Angle

Viewing angle: approximately 120° horizontal and 25–30° vertical.


Ecobee Sensor Battery Life

The new SmartSensor uses the CR-2477 battery, which stores about twice as much energy as the previous battery, a CR-2032. The CR-2477 is a 1000 mAh battery. With the new design in addition to the larger battery, Ecobee claims 5 times longer lifespan for the SmartSensor.

SmartSensor: Powered by a single CR-2477 coin-cell battery – 5 years

Room Sensor: Powered by a single CR-2032 coin-cell battery – 1 year


The SmartSensors are still too new to see if they last five years, however there have been reports of defective ones that eat through a battery in a matter of weeks. Ecobee will replace these for you if you reach out to them. They have phone, chat, and e-mail options. Just check out their website here.

My battery in the SmartSensor has not died. I have had no problems. In my room sensors, I have had to replace the battery twice in a little over a year and a half span. I’m getting about 8-9 months of life out of each battery.  If the same math transfers to the newer SmartSensor, that means I can expect about 3-4 years from each battery.

The longer battery life is mostly for convenience, as the price difference over time is negligible. Using the Amazon recommendations for each battery, a 2-pack of CR-2477 is $6.55, and a 4-pack of CR2032 is $5.49.

Just to keep the math simple, let’s say that 2-pack of CR-2477 lasts 8 years. That is 4 years per battery. And let’s assume that the 4-pack of CR-2032s actually last 4 years. You would have to buy two of the 4-pack CR-2032s to keep your Room Sensor alive as long as the SmartSensor.

That means over the course of 8 years, you would pay $6.55 for the SmartSensor batteries, and $10.98 (2 x $5.49) for the Room Sensor batteries. That is about a 3-and-a-half-dollar difference over 8 years, which is why I say it is negligible.

Ecobee Sensor Pairing

Ecobee Room Sensor Pairing

The Room Sensor required you to stand at your smart thermostat to begin the pairing process. You would power the up the Room Sensor by pulling the plastic tab out of the battery compartment. A menu would pop up on the Ecobee prompting you to pair the sensor. You would then walk through a few menu items to name your newly paired sensor, as well as choose which comfort settings to use it with.

Ecobee SmartSensor Pairing

The SmartSensor can pairing process can be completed from the app, from anywhere in the house. This process is done by opening the Ecobee app, going to the add new device menu, scanning the QR code on the sensor, and then powering up the sensor. The device is now ready to use, can you can complete the other options at your convenience.

Ecobee Sensor Physical Appearance

The Ecobee SmartSensor’s physical appearance is where the most apparent differences in the redesign are. The old Room Sensor had a noticeable cutout to enable motion/occupancy detection whereas the new SmartSensor is one solid surface. This, in my opinion, give it a more elegant than the prior design.

The only downside is the increased depth of the SmartSensor. This is presumably for the increased battery size. The height and width of the SmartSensor are actually lightly narrower.

SmartSensor Dimensions

Height: 40 mm (1.58 in)

With stand: 50 mm (1.97 in)

Width: 40 mm (1.6 in)

Depth: 26.4 mm (1.03 in)

Room Sensor Dimensions

Height: 44 mm (1.7 in)

With stand: 54 mm (2.2 in)

Width: 44 mm (1.7 in)

Depth: 20 mm (0.8 in)

For those who don’t want to attach the sensor to the wall, the SmartSensor comes with a magnetic base. The old Room Sensor had a clip-on plastic base that served the same purpose, but was not as aesthetically pleasing.