Connected radiators and the end of the thermostat

After Google acquired Nest a couple of years ago, the smart thermostat market has rapidly accelerated and has seen the emergence of several new companies. The US market has largely been dominated by Nest, with a couple of new versions released, and by Ecobee with their HomeKit compatible thermostat equipped with remote sensors.

Interesting smart thermostat activity has also happened in Europe last year. Tado, a Germany-based thermostat which was born as the European alternative to Nest, and Netatmo, a French based company which designs smart home products, have consolidated their market and dominated the thermostat space.

Basically these companies have upgraded traditional thermostats with IoT technology, such as presence detection, geofencing functionalities, intelligent algorithms for learning user habits, intuitive user interfaces, etc. Besides bringing cool and intuitive monitoring and control functionalities (like interacting with the thermostat by means of an app, by voice or in an automatic way), these technologies have brought a reduction of the energy bills. Having a thermostat which detects that you are not at home and adjusts the temperature accordingly, clearly brings more peace of mind and money saving to homeowners.

However, even though IoT enabled, connected and smart, these thermostats remain centralized and do not solve the major problems of traditional thermostats. They still control the heating system based on the temperature measured and on the presence detected in one single place of the house, heating every room in the same way. Ecobee has gone one step further by adding presence and temperature sensors which you can bring in the room where you are or where you want a certain temperature. But without actuators, the rooms are still heated all at the same time and in the same way.

In heating systems based on hot water radiators, this problem has traditionally been addressed with the use of Thermostatic Radiator Valves (TRVs), which control the hot water flow in the radiators based on a certain temperature. These devices are usually controlled manually or electronically, and in both cases they are difficult to manage. In the manual case, you should go to every radiator and turn a knob, even multiple times a day. In the electronic case, you can set a schedule for every radiator, but in case those schedules change you still have to go through every radiator and update it.

This week there has been the announcement of a new type of IoT device which will probably change the way thermostats are conceived, at least in Europe where water based radiators are still the most diffused heating technology. Tado and Netatmo have announced the IoT enabled TRVs. The valves communicate with the main thermostat, which can now keep different rooms at different temperature levels. The valve basically acts as a room thermostat, which can sense the temperature of the room and can control the radiator in order to reach the desired temperature. The valves are connected to the main thermostat via low power radio protocols. In case of Netatmo, it seems that the 6LowPAN protocol is used, while it is not specified for the Tado’s valves. It is not totally clear to me whether these valves are equipped with presence detection technologies. A couple of articles do mention that but in a rather vague way and without specifying what kind of presence detection technology they use. It would be interesting to know more about this.

Having sensors and actuators devices in every room, the thermostat becomes much more powerful and has greater potential in terms of energy savings. It is rather common to have rooms which are more frequently used than others and it makes totally sense to heat rooms based on their use. I also think that once having connected radiators (which are also thermostats) in every room, a central thermostat is not needed anymore. Sensing the temperature and presence in the place where the main thermostat is located is not needed, as the whole heating system is controlled in a distributed way. The main thermostat only acts as a central display and a relay for switching on and off the boiler.

Moving from centralized to distributed heating/cooling control has been our main principle we have been following at Modosmart since we started the company two years ago. We firmly believe that IoT has all the needed ingredients for distributing heating monitoring and control across the whole house or apartments. That’s the reason why we have been totally focused on developing devices and solutions which deploy sensing (temperature, humidity, motion, presence, open doors/windows) and actuation (radiator and air-conditioner control) in every room. If you want to know more about our devices and solutions do not hesitate to contact us at



Leave a Reply

Your email address will not be published. Required fields are marked *