[SahAssar]

People don't generally need to communicate the difference between 20C and 20.6C (68F and 69F) unless measuring it directly, in which case you would use the exact decimal number.

I also don't think most people can tell the difference between 68F and 69F unless they are experiencing them very close between, and the perceived heat at that precision is dependent on a lot more than just the measured heat.

I don't get why saying "in the 70s" is better than saying "around 24" besides being used to one way or the other.

Fahrenheit is not better and for any scientific/engineering/proper measurement you would use celsius or kelvin (which shares a scale with celsius but with a different zero-point) anyway, so why keep fahrenheit? Unless for purely traditional or cultural reasons.

[vidarh]

We tend to be much better at noticing temperature changes than fixed temperatures anyway, and more likely to reach to feeling that we're getting warmer or colder, than the specific temperature differential causing it. I think a lot of the people who think they feel differences at that precision really are feeling the difference of their heating/cooling turning on or off at different intervals. As I noted in another comment, having spent time trying to figure out how to make all of my living room - which isn't that big - comfortable at the same time, the difference is often huge, even with thermostats with 0.1 steps, because when the thermostats triggers, it's not like it will precisely lift the temperature at its measured zone by 0.1 steps. It will either heat my underfloor heating or my radiators to a point where they will first hit a 0.1 increase, plus the margin before it triggers the other direction again, at which point they'll get turned off, and significantly overshoot while the floor or radiator cools down. Setting a thermostat to 24.3 is not going to leave you with a room at 24.3, it's going to leave you with a room fluctuating between something like 22 and 26 in different places and heights and time intervals...

The only time I'll buy that anyone manages that level of precision is if they live in a very modern house with near perfect insulation where the heating or cooling input needed to keep it in balance is near nothing.

[hot_gril]

It's more achievable in a small single-story apartment, or better yet, a car. I can really feel the difference without looking at the number. There's also what you said about the trigger points, but it's still a good reason to have precision on a thermostat. I felt like it was slightly too cold yesterday, so I moved the thermostat up 1˚F and it felt warm enough.

And I'm not a scientist, but in science classes we were only using Kelvin, not Celsius. C and F aren't useful for proportions because 0 isn't 0. Even Rankine would be fine, just use different constants.