Using non-thermostatic mode with Tado Smart AC Control

Tado°'s Smart AC Control is one of only a couple of devices that bring smart features to owners of standalone air conditioning units. Smart AC Control functions largely like the smart thermostats available for whole home systems in that is monitors and regulates the temperature by controlling the air conditioner according to settings and schedules that can be configured via it's smart phone app.

Tado° refers to the default operating mode of the Smart AC Control as 'thermostatic'. I've written extensively about how this works in my comparison review, but essentially it directly controls the on/off state of the AC unit to regulate the room temperature based on it's own temperature sensor. In order to do this you need to program the commands for maximum cooling and maximum heating to prevent the AC trying to do it's own thing.

Tado° claims by regulating the system according to presence, schedules and local weather conditions (I haven't actually observed any change in behavior based on weather, although the apps records the forecast conditions in it's reporting) it can save as much a 40% on your energy usage. The app will produce an energy saving report every month which claims to reflect this, but I'm skeptical. My reasons are primarily that tado° can't possibly know what my normal usage would be, or what my particular AC's energy consumption would be under it's own operation. One can argue that it's an educated guess and provides indicative savings, but my anecdotal experience doesn't reflect that assumption, although to be fair it's based on 'dated cooling technology'.

This is where we find the big hole in the thermostatic approach; when it is used on inverter air conditioning systems. If you've sprung the extra cost for one of these, it's precisely because they are much better able to regulate energy usage to maintain a set temperature by adjusting power consumption dynamically. Smart AC Control undermines this by forcing the unit to run flat out in short bursts. Sure, it works well and does the job, but it's probably not the best way to run an inverter system. There is another option, however.

tado° provides for a 'non-thermostatic' mode which let's the AC manage it's own temperature, while still allowing for smartphone control, presence and schedule settings. This mode isn't mentioned in the normal setup, and it's buried under the settings section of the app. You can find the mode switch from the home menu of the tado° app. Tap on Settings, select the Room containing the AC, tap Air Conditioner, and then the Switch to Non-Thermostatic Control option will be at the bottom of the page.

Testing the command sets

Testing the command sets

Setting this mode up can be a bit painful, but your mileage will vary. By default, the setup process for non-thermostatic control will take you through an auto-detection process. tado° has a database of AC control sets that it will try and select from. You'll be asked to specify if your remote and head unit has a display that shows the current settings, and then to select from a list of manufacturers. Based on this, the number of potential command sets will be loaded and a tests sequence will start.

The idea of the test sequence is that the Smart AC Control will send on/off commands to your AC to determine which ones it will respond to. In my case, there were 39 potential sets. Each ones is tried and you simply need to tap on a button for No Response or AC Responds. This seems simple enough, but here's where it starts to unravel. Of the 39, I had 19 basic responses. I expected the app would now try to narrow it down, but no. I was simply presented with a list of the 19 command sets and told to pick the best one.

You are able to go into each set and run some sample settings, but these are limited to on/off, temperature, and heat or cool mode. Given almost all of the sets looked the same, it was impossible to differentiate whether one was better than another, and these was no way to determine that by testing the other features of the AC. I promptly (well, eventually) gave up on that when I noticed that at the bottom was a small link for "Teach Tado".

The teaching mode seems a better way to go, but it depends how much functionality you want to expose in the app. The commands from the remote are batched and so the app needs to learn each combination separately. If you want to include all the functions for modes, temperatures, fan speeds and vent positions....good luck. This is extra painful, because it's possible for a given command from the remote to be received incorrectly. A moment of interference, bad positioning, or tapping the app button too quickly will result in a partial command being learned, which obviously won't work and will need to be retried. You won't know that until during the test phase, though. Pro Tip: Test every setting to be sure.

Given that I always use the same fan setting and vent position, I opted to limit the training modes to Heat and Cool with just that one setting. I further reduced the training cycles by limiting the temperature range to that which I would actually use for each of the two modes. The tado° app will ask you for the highest and lowest that the remote will go, but you probably don't need them all. Taking this approach cut down the number of commands to program to about 12, which was much more manageable.

This may seem limited, but it actually provides the same functionality as the thermostatic mode in that you don't get the option to control the other settings of the AC anyway. By doing this you now have the same benefits of the Smart AC Control, but the AC can use it's inverter functionality to maintain the temperature. Temperature and mode can be specified via schedules based on whether someone is home or not, and the AC temp, mode and on/off state can be adjusted via the app as before.

If you have an inverter unit, this is worth the setup time. Note that while the manual teaching mode is my preference, you have to run through the auto-detection phase first before it gives you the option. You may also have better luck with the auto detection if you end up with a smaller set of possible matches.