Reviews You Can Rely On

Johnson Controls GLAS Review

This expensive thermostat looks great but its performance left a bit to be desired
Johnson Controls GLAS
Credit: Johnson Controls
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Price:   $250 List | $145.00 at Amazon
Pros:  Stylish, accurate
Cons:  Very expensive, seemed a little buggy to us
Manufacturer:   Johnson Controls
By David Wise and Austin Palmer  ⋅  Oct 2, 2018
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65
OVERALL
SCORE


RANKED
#3 of 9
  • Ease of Use - 40% 6
  • Install & Support - 30% 7
  • Remote Access - 20% 6
  • Accuracy - 10% 8

Our Verdict

Finishing close to the top of the group, the GLAS is a solid thermostat, but couldn't quite topple our top recommendations. It has a particularly sleek and stylish design that stands out from the rest, but we found the looks of this product to be very dependent on the type of walls you have and how clean it is — we found it to be a total magnet for dust and fingerprints. It does stand out by having a built-in set of air quality sensors and works with both Alexa and Cortana and is very accurate. Unfortunately, it is also one of the most expensive thermostats we have tested to date and its overall operation seemed a little buggy and less user-friendly than some of the top models. It might be a great bet if you absolutely love the look — and live somewhere with perfect walls, but otherwise, you are probably best served by another model.

Compare to Similar Products

 
Johnson Controls GLAS
Awards  Editors' Choice Award Best Buy Award Editors' Choice Award Best Buy Award 
Price $250 List
$145.00 at Amazon
$249 List
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$130 List
$114.49 at Amazon
$250 List
$243.99 at Amazon
$50 List
Overall Score Sort Icon
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Pros Stylish, accurateSleek, easy to install, accurateAccurate, easy to install, great remote access featuresIntegrated Alexa voice assistant, easy to installInexpensive, includes a C-wire adapter, great remote access features
Cons Very expensive, seemed a little buggy to usExpensive, support just refers you to a Nest ProVery app reliant, can be harder to set up a scheduleLackluster performance in our accuracy tests, could be more intuitive to useNot our favorite technical support, could be more accurate
Bottom Line This expensive thermostat looks great but its performance left a bit to be desiredThis is easy to use, easy to install, and is both accurate and stylishIf you are looking for an all-around excellent smart thermostat and still trying to save some money, then this is the right choice for youIf you want an integrated voice assistant right on your wall, then this is the product for youIf you are searching for a top-tier smart thermostat on a budget, then we think this is a wise choice
Rating Categories Johnson Controls GLAS Nest Learning Therm... Google Nest Thermostat SmartThermostat wit... Wyze Thermostat
Ease Of Use (40%)
6.0
7.0
5.0
6.0
5.0
Install & Support (30%)
7.0
8.0
8.0
8.0
7.0
Remote Access (20%)
6.0
6.0
7.0
6.0
8.0
Accuracy (10%)
8.0
9.0
9.0
5.0
6.0
Specs Johnson Controls GLAS Nest Learning Therm... Google Nest Thermostat SmartThermostat wit... Wyze Thermostat
Colors Transparent screen with silver base Stainless Steel, Copper, White, Black, Mirror Black, Brass, Polished Steel Snow, Sand, Fog, Charcoal Black Black, white
Battery Backup No Built-in, rechargeable lithium-ion battery Yes No No
Learning/ Adaptive Controls No Yes - "Nest Sense" No Yes - adaptive No
Dimensions Length: 5 in
Width: 5.5 in
Depth: 1 in
Diameter: 3.3 in
Depth: 1.21 in
Diameter: 3.31 in
Depth: 1.07 in
Length: 4.29 in
Width: 4.29 in
Depth: 1.00 in
Length: 4.7 in
Width: 2.6 in
Depth: 1.3 in
Works Directly with Alexa/Amazon Echo Yes; Also built-in Cortana Yes Yes Built-in Yes
Works with Apple HomeKit No No No Yes No
Model # SIO2-10000 T3007ES G4CVZ SmartThermostat with voice control WTHERM

Our Analysis and Test Results

This model finished right behind the Nest Thermostat E and the Nest Learning Thermostat. The GLAS is a bit harder to install, is slightly less accurate, and is a little bit harder to operate overall, but it is by far the most expensive.

The GLAS has quite a unique aesthetic.
The GLAS has quite a unique aesthetic.
Credit: Jenna Ammerman

Performance Comparison


In the two years or so that we have been testing and rating wifi smart thermostats, we have been continually refining our testing procedures and updating our review as new models have come out, buying them all to test and score. We split our testing procedure into four weighted testing metrics, with the GLAS' results shown below.

This product is decently easy to use, but does accumulate...
This product is decently easy to use, but does accumulate fingerprints like crazy.
Credit: Jenna Ammerman

Ease of Use


Responsible for almost half of the total score at 40%, our Ease of Use metric has the most bearing on the overall score of each product. We looked at the difficulty in the initial setup and configuration process, how hard it is to set a schedule, adjust the temperature, time, or other advanced settings, as well as the clarity of the information displayed. The Johnson Controls GLAS did fairly well, earning a 6 out of 10 for its performance.

Once the thermostat is mounted to the wall, the initial configuration is nice and simple, with prompts that guide you through the whole process. The time and date set automatically when the device is connected to wifi, though you do need to set which time zone you are in. There aren't a ton of advanced settings to configure, but the single menu of additional settings is relatively easy to navigate and decently user-friendly.

The settings are laid out in an intuitive and user-friendly way.
The settings are laid out in an intuitive and user-friendly way.
Credit: Jenna Ammerman

It also is very easy to adjust the current temperature setpoint by tapping it and then using the arrow icons.

Adjusting the current temperature is done by tapping the smaller...
Adjusting the current temperature is done by tapping the smaller number and using the arrow keys that appear.
Credit: Jenna Ammerman

The scheduling is a little finicky, as you set the temperature for when you are home and away, then set what times you plan on being at home, rather than setting different temperatures for specific times.

The scheduling isn't the most intuitive.
The scheduling isn't the most intuitive.
Credit: Jenna Ammerman

The information displayed on the GLAS is clear and easy to read, with the option to adjust the brightness to maximize visibility for your home's lighting situation. However, the screen seems to be an absolute dust magnet and holds fingerprints very well, making relatively frequent cleaning a must.

This thermostat does have an exceptionally nice display.
This thermostat does have an exceptionally nice display.
Credit: Jenna Ammerman

If you are embracing the smart home side of this product, it can interface with both Microsoft's Cortana and Amazon's Alexa, though we did find Alexa to have a bit of an edge at the time of writing. This thermostat also has air quality sensors and can activate the fan according to their reading, as well as run some auxiliary appliances, such as a humidifier or dehumidifier.

The transparent nature of this product makes it a bit more work to...
The transparent nature of this product makes it a bit more work to install.
Credit: Jenna Ammerman

Install & Support


Worth 30% of the total score for the GLAS, our next metric moved on to evaluating how much effort is required to physically install the thermostat and how helpful we found the customer support team to be when faced with our questions. The GLAS again scored well, earning a 7 out of 10 for its efforts.

We found the customer support to be quite helpful, even though it did take a few back-and-forths over email until we got some of our smart home issues ironed out. The standard installation process is quite pain-free with one exception and there are guided prompts in the app and on the thermostat to lead you through it.

The setup process, once it is mounted, is made quite easy with a...
The setup process, once it is mounted, is made quite easy with a series of prompts.
Credit: Jenna Ammerman

The main difficulty with the installation of this thermostat is the lack of space. You have a much smaller space to work with, as the wiring is all done through the non-transparent part of the thermostat. This also means that this thermostat won't do the best job of hiding imperfections or damage from your old thermostat's mounting method, so some touch-up work may be required before installing the GLAS.

The white trim plate can be used to hide imperfections on your wall.
The white trim plate can be used to hide imperfections on your wall.
Credit: Jenna Ammerman

Remote Access


One of the nicest things about these products is the ability to adjust or check the temperature remotely — a great way to make sure your HVAC system is behaving while you are on vacation or make sure your home is the perfect temperature the moment you walk in the door. For this metric, we ranked and scored how easy it is to adjust the temperature or schedule using the mobile app, as well as the other types of adjustments you can make. It makes up 20% of the total score, with the GLAS again doing decently well, meriting a 6 out of 10.

The mobile app is very intuitive and easy to use — essentially an almost exact mirror of the interface on the thermostat itself. You can't make any equipment adjustments remotely, but you can update or reset the device. Additionally, some of the settings are even more consolidated on the mobile app, requiring you to navigate through fewer submenus to perform tasks like activating "Vacation" mode.

Testing the accuracy of this thermometer using a precision thermostat.
Testing the accuracy of this thermometer using a precision thermostat.
Credit: Jenna Ammerman

Accuracy


For the remaining 10% of the total score, we compared how accurate each thermostat measured the temperature, comparing them against a laboratory grade digital thermometer. The GLAS is one of the more accurate models we have tested, earning it an 8 out of 10.

This thermostat usually displayed a temperature that was within a single degree of our control, though we did notice larger discrepancies for a short period right after the thermostat was installed — these usually abated within a matter of hours.

Value


This product is a terribly budget pick, being one of the most expensive we have seen and forcing you to pay a premium price for looks.

Conclusion


We were very excited about the prospects of this thermostat and ended up coming away disappointed. This device did quite well overall, but its excessively premium price doesn't quite mess with its second or third tier performance, precluding us from recommending it.

David Wise and Austin Palmer