When I was a child, I lived in a house that had a thermostat. You told it what temperature you wished to have in the house, and it obeyed. It was a round thing on the wall in the 3 BR-1 BA classic 1950s house that we occupied in the post-WWII inner suburbs of Minneapolis, MN. I was a tiny pipsqueak, of single-digit age, and I was a very proud girl because the thermostat said “Honeywell” on it and that’s where my dad worked. It looked something like this, only brass colored (not white).
When I was a teenager, we had a newer house in America, and it still had a Honeywell thermostat but this one was programmable. My father was no longer in the business, but we could set the thing to a temperature–different for day and night by about ten degrees F–and it would obey. It looked like this.
When I was a young married person, I had zone heating. Which means that I had a thermostat each in several different regions of the house, and I could control (program) the temperature independently in each. It was either three or four separate regions, I do not recall the exact details. But it was good, and it was energy-efficient because you did not need to heat the parts of the house in which you did not spend time.
In 2006, I moved to England. There is no thermostat. There are radiators.
(I have lived in two different flats with the same 1-BR layout and radiators, so I guess this is not a one-off.) The radiators have valves, they are on or off. In my current living room there are four, in the bedroom 2, in the bathroom 1. In order to control the temperature of the flat, I must decide how many radiator valves to open and how long to keep them open. Manually.
Being a science-y type, I have opted to enlist the help of my cooking probe thermometer:
to try and ascertain the current temperature in the flat, and how it might perchance be changed with the opening and closing of certain radiator valves.
The inertia in the system is such that I cannot change the day to night temperature the way I did in the US, I must aim for an average. The probe currently reads 67F which I guess is a pretty good moderate setting–too warm in the night and too cold in the day compared to the thermostat temperatures of my youth. I will try in the next day or so to bring the average down to 65, as that seems a reasonable compromise to me. But I am very much aware of the fact that such changes I make are but a small drop in the large bucket of the energy reforms that need to be made in the interests of the world.
Systems that input heat only when you need it: golden. Radiators that require cooking implements to incorporate: needs some work. I’d happily take a 1980s vintage thermostat and the ability to turn down the radiators at times, so as to save night-time energy if we could determine when the shut down should happen.