Probably depends largely on one's personal comfort level. I like around 23 and am still wearing at least two layers. Body build comes into it. Fat people are insulated against the cold.
Agree with you about stuffiness.
Everyone should have whatever makes them comfortable. I only raised it because drsmith and smurf were both seeming to be complaining about the cold and saying their houses were around 15. I was just curious about why they'd willingly be uncomfortable.
Personally I find anything below 21 uncomfortably cold and normally I heat the house to 21 - 22 degrees. Problem is that most days during winter, it's around 12 - 13 inside when I get home and it takes quite a while by the time I carry the wood up the steps into the house, get the fire going, wait for the fire to warm up, then wait for it to actually heat the house.
As an example, I got home 70 minutes ago and it was 13.5 inside then. Now the fire is starting to really get going and it's up to 15. Give it another half hour and it will have shot up to 21 or so. So it's just a timing issue really.
Ideally, I'd like to install gas central heating since that would be very effective at heating and is relatively cheap to install with the deal the gas company is offering (effectively a $3000 discount on the cost of installing it). Only trouble is, I'm nowhere near a gas pipe... Hence the planned air-conditioner.
Regarding temperatures generally, a few observations:
1. I certainly had fewer colds when I lived in a house that had 24/7 heating and was never cold. No doubt about that at all - I get at least one cold every year now versus very few when living there.
2. At work we actually run the works depot common area where workers start / finsish from at 24 during Winter, 22 during Summer. The reason is simply that with workers out in the cold all day and sometimes getting wet too (we work rain or shine), they like it to be toasty warm when they come back at the end of the day so as to "thaw out". The cost of heating is trivial compared to the benefit of keeping people happy.
Regarding my previous post about costs, I should add that this is only for heating and not including power used for everything else.
One thing that amazes me, is how seemingly unintelligent animals can work things out that humans often fail to grasp. I have some mice with a cage joined by a tunnel to a plastic maze. On one rather cold night, the mice managed to shift fully two
human hand fulls of shredded paper through the small tunnel and used it to effectively insulate the maze. Not just paper thrown around randomly - they actually had enough sense to insulate on the other side of the walls of the maze around the area they've decided to sleep in. 8 degrees where they're kept in the garage, very warm inside the maze with all that paper they've taken in. Must have taken them quite some time since a mouse can't really carry too much at once, and they have to go through the tunnel (which is only slightly wider than a mouse) to get it all in. Looks a bit like an igloo the way they've done it, insulated with the paper on all sides with only one small entrance back into the rest of the maze. Smarter than I'd expected...