The principle of underfloor heating is: there are tubes laid in concrete of floor through which water heated by gas boiler is circulating. Heated pipes are heating floor concrete and then warm floor of a room heats all space. The pipes in the floor are installed in a certain order to form loops, the beginning and the end of each loop is connected to central manifold.
All pipes are covered up with concrete.
Heating by radiators is very different from heating by underfloor pipes, because in the case of radiators, then the boiler starts heating radiator become warm very soon and, in a few minutes, radiator is heating space around. Then the boiler shuts down radiator becomes cool in a short period. With underfloor heating the process is different. It takes long time to heat the floor to the temperature required for floor heating. And then the boiler shuts down, floor cools down in several hours. And because the floor cannot be very hot, simply because it would be too hot to walk on them, it takes a long time to heat the room.
With underfloor heating to hold the stable temperature in a room is almost impossible. And then there is mixed system of underfloor heating and radiators – situation gets even more complicated. Of course, always there is an option just to turn on the boiler and not regulate anything, but in this case, there will be zero comfort at home. And it will require a lot more gas for heating, than it would require with thermostats.
How radiators can be controlled with Netatmo Smart Radiator valves, you can find here: Smart Heating part2: how to connect thermostat and smart radiator valves.
And now, about underfloor heating control.
Underfloor heating is regulated by using actuators, mounted on central manifold.
These actuators simply close or open the loop of heating pipes in the floor. When loop is open, water flows – floor is heated. If loop is closed, water is not circulating – floor is not heated.
Room thermostat controls actuator. If there is more than one loop in one room, actuators of these loops are grouped to zone, for simultaneous control by one thermostat.
For underfloor heating control relay of Netatmo Smart Thermostat is connected to actuator. Then set temperature is reached – thermostat close the loop or zone of loops to which it is connected. If tempetarute of room goes down below required – thermostat opens the loop and the room is heated. Then I connected thermostat to actuator I have found that when the room requires the heat from boiler – nothing happens. Because I connected thermostat only to actuator and in this situation the boiler does not knows that it is required to turn on and make some heat. But the solution was found – simple relay with two groups will fix the problem. This relay is designed for situations, when one control unit needs to control two separate devices. Then the room thermostat requires the heat – it will open the loop with actuator and at the same time it will turn on the boiler. Schema, how to connect thermostat.
With all actuators and all wires connected manifold now looks like this
I did not manage to lay down all the cables very neat, but it is not a problem for me, because the manifold will be hidden in the wall.
I like Netatmo Smart Thermostat, because it can be mounted in any place in a room and if there is a need to move it to another location – no problem, it is wireless!
If you don’t like it on the wall, or you want to set room temperature by the exact spot in a room, thermostat can be placed for example on the desk or on a shelf.
Using Netatmo Smart Thermostat, you can change room temperature by pressing top or a bottom of thermostat, but I doubt that manual control will be used a lot. Usually, the temperature is regulated by schedule and if you want more heat, simply say : Hey Siri, set living room to 23.
As you can see, modern and smart heating system can be installed very easy and quick. Almost every heating system is compatible with Netatmo Smart Thermostat and in a few hours or event few minutes it can be overhauled to be smart heating system.
Next time, in the last part of my smart home heating system blog series I will show you software part of Netatmo Smart Thermostat.