Marketed as nursery monitor, the First Alert OneLink Wi-FI Environment Monitor is more than just for keeping tabs on your child. For our review, we picked up the Nuk version of the device, which can be found pretty inexpensively via various online retailers. This version is identical to the “normal” First Alert branded offering, other than the word Nuk printed on the outside of the packaging. The device itself does not have any Nuk branding on it, and this version is clearly an attempt to get the device into as many outlets as possible, from traditional home improvement stores to the large “baby” store chains. The environment monitor features three different sensors, each exposed to HomeKit, one for temperature, humidity, and carbon monoxide, and includes a battery backup as well as an audible “alarm”, that is reminiscent of a smoke alarm. Speaking of smoke alarms, smoke detection is not included in this device, which is strange considering that First Alert is synonymous with fire safety. So how does a “nursery” monitor work in the world of HomeKit? Let’s find out.
Design-wise, First Alert chose a unique modular housing, which is compact and able to fit just about anywhere in the home. The mostly white frame takes on somewhat of a cylindrical shape, and has a large status LED ring around the top. The back of the unit has 3 “ports” which are either tied to ventilation, carbon monoxide detection, or just for the audio alarm. There are no buttons on the device itself, save for a test button which is located underneath the unit, and this button also acts a reset if pressed 5 times in rapid succession. As I mentioned, the device is modular, in that the top of it can be rotated to remove, and inside is the backup battery, which is hidden beneath a plate held together with a screw. The battery is replaceable, and it is a standard CR2 battery, but the company does not provide an expected battery life. The life of the unit itself does has a life expectancy, as it falls under the realm of a safety sensor, and the company states that it is 10 years, which is covered via a warranty. Back on the outside of the unit, the LED ring can act as a nightlight (again, this was designed as a nursery monitor), which can be adjusted via the OneLink App (more on that later). The LED ring also provides a visual indicator as to the temperature of the room that it is situated in, which is tied to the set points established in the accompanying app. When the temperature in the room is within the desired range, the LED will be white, when the room is warmer, the LED will change to yellow, and finally the light will turn to blue when it is colder. The device also features a 4th color, which is red, and will change to this when CO levels have been detected. Aside from the previously mentioned battery backup, the device is powered by a fairly typical power plug, which houses the HomeKit code for the device.
Setting up the environment monitor was a different process than what I am accustomed to in the HomeKit universe. After unboxing the device and plugging it into power, the environment monitor was not able to be found via the native iOS App, and I had to go through the OneLink App before it could be seen and paired. Oddly enough, the OneLink App uses the same exact screens, with the traditional “scan code” screen as the Home App, but I simply could not get it to show up in Apple’s solution out of the box. After following a few prompts in the OneLink app, one for assigning the room for the device, activating the battery backup, and using the aforementioned scan screen for the HomeKit code, the device connects via Wi-Fi to your home network and is ready to go.
Once added, the OneLink App will display a list of only your devices from First Alert, no other HomeKit devices are shown. After tapping on the device from the list, a “summary” screen for the environment monitor will be displayed, which features a thermostat like visual indicator for the room temperature, as well as Humidity, Air Quality, albeit in smaller form. At the top of this screen, a recent history tab can be found, which provides a timeline of events in the home, which include when any tests were conducted. At the very bottom of the device summary is an option to adjust the brightness of the LED ring on the device, which is handy for using it as a night light, or just for turning it off altogether. The final option on the summary page is a “Test” button to, as you would guess, test the alarm functionality, which sets off a series of loud, but not overbearing beeps. Diving into the settings for the device, options for setting temperature and humidity ranges can be found, which come in the form of both the previously mentioned visual color indicators on the device itself, but also for notifications sent to your device via the OneLink App. Current battery life is also displayed in the settings pane, as well as an option for firmware updates, but I have not seen one as of yet.
Over in the iOS Home App, the OneLink Environment Monitor is displayed as 3 separate sensors, one for temperature, humidity and CO. While the temperature and humidity device “tiles” in the Home app are fairly standard, just reporting battery level and the associated room readings, the CO sensor features current and peak levels, which is handy to be able to reference if there is any doubt about the safety in your home. Of course, limitations within the iOS Home App prevent things such as temperature to be used in automations, this can be circumvented with 3rd party solutions, and we recently provided a brief guide as to how to accomplish this. For the CO sensor, automations can be made to allow it to trigger other devices if CO is detected, which can perhaps help if needed by turning on fans, turning off the thermostat, and turning on lights. Sadly, the LED indicator light on the device itself is not exposed to HomeKit, which is a missed opportunity as it has the capabilities to show various colors, and the brightness can already be controlled via the OneLink App, but we assume that this is by design as it could cause confusion with regards to the previously described safety visuals.
As far as accuracy of the sensor readings go, temperature and humidity seen to be aligned with other sensors in my home, with just a 1 to 2 degree variance seen, which is par for the course for these types of devices. I cannot attest to the CO sensor portion, as there have been no events (or any ppm readings above 0 at all) in my home, but that is certainly a good thing in this case. Notifications provided by the OneLink App are the sore spot for this device, with notifications for tests that I have performed coming in minutes, and even in one case, hours after the test had completed. Keep in mind that this is just for the App itself, and does not apply to the visual and audio portion of the device, those all sounded and displayed instantly.
At the end of the day, the First Alert OneLink Wi-Fi Environment Monitor is a solid device if it can be found lower than its retail asking price of $99.95. At that price I would point those interested in just temperature and humidity monitoring to more affordable options such as the Onvis SMS1, or Hue Motion Sensors. However, as I stated before, the OneLink Environment Monitor can be found cheap, and in my case I was able to pick one up for just $20 new. The presence of the CO sensor alone in this device makes it easy to recommend at the discounted price, and when mixed in with the other 2 sensors, it makes it a downright steal. If you are looking for CO detection and can only find the environment monitor at or near its retail price, you may be better suited to pick up the company’s dedicated smoke/CO detection combo units that are near the same price.