Answered other. I have one window air conditioner, downstairs in the kitchen, and if it’s hot outside there is no way it will get my upstairs bedroom cool.
My usual air conditioning, which used to work fine here about 360 days out of the year and still works fine on at least 340, is that in weather too hot for me I open windows at night and shut them in the morning. If the day’s going to be in the 80’s or 90’s (I’m assuming from the OP that we’re talking in Fahrenheit here), then if I can get the house down to low 60’s or below by dawn it won’t much be out of the mid-70’s by the end of the day. If outdoor temperatures don’t go down at least to the mid-60’s this technique doesn’t work; hence the one window airconditioner.
I think a comfortable bedroom sleeping temperature is anywhere from upper 50’s to low 60’s. I’d much rather a cold room with blankets and comfortors (and cats) than one too hot for covers.
I have no AC but my thermostat is programmed to set the heat to 61° at night (mainly for winter although occasionally summer nights might get that cold here on the Northern California coast). It’s rare for the daytime temperature to get above 90° here and hot nights are essentially nonexistent.
I have a Nest thermostat that can detect whether I’m home or not based on my phone’s location. In the summer I have the temperature set to 80 when I’m home, 85 when I’m not home.
I’m in inland Northern California, where can get very hot during the day, but with low humidity. That low humidity means the temperature can drop by 30 degrees Fahrenheit at night. I also have a whole house fan. So what I’ve been doing lately is to open the windows and turn on the whole house fan around 8:30 pm, which seems to be about the time the outside temperature drops below the inside temperature. By bed time this usually gets the inside temperature down to around 77F. At bed time I turn off the fan and close some windows but leave a few open a few inches with that little thingy that pops up to prevent burglars from opening them further. When I wake up the next morning the inside temperature will have only dropped another degree or two, but the outside temperature has now dropped into the 60s unless we’re in a really hot spell. At this point I open up the windows again and turn on the whole house fan while I’m getting ready for work. The inside temperature will drop to about 70 by the time I’m ready to leave for work. Before I leave I turn off the fan and close all the windows. The temperature inside will gradually rise, but not enough for the air conditioner to kick in until I get home usually.
I voted “other” because we only have air con in one room, and it’s the room furthest from our bedroom. When it’s hot in summer, I sleep on top of the sheet (no blanket of course). When it’s cold in winter, I get a hot water bottle – low tech, but it works.
I’m much more tolerant of cold than of heat and humidity. In winter I usually keep the thermostat at 58 during the day when I’m home, 50 when I’m away and at night. I live in Maine, so I only have to use the AC maybe 10 or 12 days a month from early June to mid-September. When I do use the AC, it’s set to about 73 day and night. That’s about as warm as I can have it and still get a good night’s sleep. Believe me, I’ve tried to set it warmer to save money, but it’s not worth the misery. If it were 82 at night I doubt I could get any quality sleep at all.
I live on the coast of Maine. I have a window AC unit, but it really hasn’t gotten hot enough that I’ve needed it this year. The few days where it has gotten hot enough to put it in, I was on the road anyway, and it had cooled down by the time I got home, so I just haven’t bothered putting it in, and have been enjoying the lower electric bills as a result.
Setting the thermostat to 82° on my furnace? No way José. Might as well take a match to a stack of $100 dollar bills.
It’s at 68° most of the winter, and gets turned at the lowest possible set point as soon as the outside temperatures warrant it. It’d be at 65° or less if I were the only one in the house. Sweaters are cheap! Fuel oil costs almost $3,000 per year.
Other - it’s turned off. Airflow sucks in our home*, so it’d be useless. A ceiling fan in the bedroom makes it sleepable during the summer.
During the day, it’s set to 28° C - about 82° F.
*It’s not central A/C, which is uncommon in Australia - it’s a split system venting into the living room.
I keep the A/C at 72 around the clock. I live in the DC area in an apartment on a high floor. It’s hot and humid (93% humidity at the moment) and turning the A/C off is not an option. I’d feel sick all the time.
Not contrary to what the HVAC said. It’s letting the house warm up and then cooling it back down that causes the AC to run constantly for a long time. I had a boss years ago who destroyed a commercial AC and cost himself a huge chunk of money because he insisted on turning it off at night and starting it up again in the morning. And not just the cost of replacing the unit - it was also that the building was heating up to the high 80s (it’s not uncommon to have lows in the 80s during the summer) at night then working to cool back down to 75 during peak billing hours.
I need to have it below 70 get a good night’s sleep, preferably in the mid 60s or less. When I stay in hotels I’ll crank the AC down really low at bedtime, especially if I’m in a room where I can’t open the windows enough to let in cool outside air.
I have sensory issues and heat intolerance. My sleeping temperature is around 60, whether it’s winter or summer. Sometimes I’ll let it get colder than that in winter.
The House In The Mountains does have a thermostat, but no a/c. Until two years ago I’d never seen the thermometer reach 30ºC/86ºF there.
The House In Barcelona has one a/c unit, but so far I’ve never kept it on while sleeping; at most I’ve had it on for a while before going to bed (set it to 25ºC/77F, which is the coolest I ever set it, and once it stops the first cycle switch it off; normally if I’ve got it on it’ll be set to “dehumidify” or to 32ºC/90F). Note that it is rare for temps not to cool down to levels I consider no-a/c-needed at night: the “cold attack” is because during the day my bedroom will be closed, I cool it down only before going to bed.
