It is becoming more common in northern Europe, which sounds counterintuitive, because heating during winter is a far bigger issue here than cooling during summer.

However, many private houses get ‘heat pumps’, which gives you more heating pr kW than pure old-fashion electric heating would have given. Basically it is a backwards airconditioner.

These heat pumps can also be run backwards, and then they function as aircondition.

Quite true, and I certainly hope we are.moving further away fro the imperial system.

I am sorry I slid into a rant about the imperial system, but my initial motive was to show that for historical reasons, there is a lot more arbitrary choices in the imperial system then the metric system.

I would say Kelvin is arbitrary too. It has the temperature of 0K at a natural, non-atbitrairy point, but each increment of 1K is the same as 1°C and thus just as arbitrary as the Celcius scale.

Well, there are different levels of arbitrariness. :-)

The situation in Europe in the late 1700s and into the 1800s was that most countries had their own measures of inch, gallon and pound etc. The foot could easily vary more than 10% between countries. The naming of units was not consistent. And even seemingly specific measures differed, even inside one country, like a beer barrel being a different number of gallons than an ale barrel, or a barrel of fish being being of a different size than a barrel of grain.Just in Norway we had the Norwegian foot around 31,4 cm, being a variation of the Danish foot, that was a misreading of the Rheinish foot - but they were at least fairly similar. However, for shipping purposes, the English foot was used for the measurement of ships (important for customs and taxes), while also a bigger-than-English foot was used for measuring timber to be exported, accounting for a shrinking/drying of the timber during transport. The Swedish foot was 29.7 cm, and it was curiously divided into only 10 inches - making the Swedish inch very long and the Swedish foot fairly short. And I don’t think Scandinavia was particularly chaotic in this respect.

The whole thing was a mess, of course. So the idea of using the meter invented by the French was attractive (even though it was the French who invented it). No country’s definition of foot would be able to gain universal acceptance. The meter was originally aimed at being one ten-millionth of the distance from equator to the north pole of the earth. Nobody got ‘their’ foot or inch (or according to some legends: the foot-length or thumb-width of some famous, historical king) as the standard, so it was generally more acceptable.

Looking back, I predict that no metric-based country will ever go from the current strict ten-based increments of measures back to the imperial system with mainly two-based increments, with the occational factor of 12 (inch/feet), 11 and 5 and 3 (a mile is 8 furloughs, each of which is 10 chains of 22 yards, the yard being 3 feet.

It is SO not going to be the next measuring system of a country were the metric system have gained foothold.

Yeah, I know they managed to standardize the imperial measures after everyone but UK and US stopped using them. But it is still not going to happen.

The operative words here are ‘likely’, ‘unlikely’ and ‘probably’, which function as verbal CYA for a retired general giving an over-simplified analysis based on insufficient background knowledge.