Most American homes have forced air heating and ventilation, but in much of the world people use hydronic, or hot water heating. There are a couple of reasons; the main one is that when central heating was developed it was much easier to install little pipes than big ducts in retrofits. It also didn’t need pumps or electricity and could move the water by convection. There are also real benefits of hydronic heating: you aren’t moving dust around; you don’t have nice big noise pipes between rooms. It’s quiet.
But one serious problem has always been control. It is hard to balance radiators; there is a lot of thermal lag, the time it takes for the radiators to adjust. You can get individual thermostatic valves, but they each have to be individually set.
Now the French company Netatmo is introducing smart radiator valves that work with its Starck-designed smart thermostat. It’s all designed by Philippe Starck to look pretty, but they also connect through Apple HomeKit so that you can control each room independently through Siri. According to Dezeen, it also “reacts to the occupants of the house in real time, by analysing factors like the number of people in the room and whether electrical appliances are being used” to adjust the heating accordingly. And if you leave a window open, it will stop heating the room.
As houses get more energy efficient, it makes some sense to separate heating from ventilation, and to have the ability to control heating so precisely. It’s also nice to eliminate bulkheads and boxes that come with forced air. With technology like this, perhaps hot water heating might make a comeback in North America.
Dezeen reports that "that the system works with 90 per cent of normal hot water radiators on the European market. It is not currently compatible with international heating systems." By that I hope they mean that it just works with hydronic systems, since there are quite a few homes in North America with Runtal and other European radiators. I would put these in my house right now.