Florida here. My AC only runs non-stop if all of this hits at once: I let it get hot inside, it's 95F outside, and it's late afternoon where I catch zero shade.

The spray foam attic insulation under the roof is the bomb. If I had my druthers I'd force that in all new construction. Insane that we still use fiberglass and other crap.

Which is more expensive, your A/C running 24/7 or it suddenly stopping?

that was me until i realized my roommate set the fan to on instead of auto

I heard spray insulation voids your homeowners insurance. Is that still true?

Well it's free after it suddenly stops it only costs you money to get it going again.

This is why you get a whole house fan… if you are able to have one installed.

My understanding is that it's not bad when done correctly, but if they screw up the install it can be a nightmare and a huge safety issue. They screw up the mixture and now you've got extremely hard to remove foam stuck to everything that's going to off gas dangerous chemicals for 20 years. It can go bad enough to completely condemn the home.

An example: old AC running 24/7 keeping the house around 80 degrees. Electricity bills between $250-300 per month.

System replacement was ~$15k. System runs regularly now and monthly electricity bill is about $150-200 and keeps the house at 75.

I'm using a swamp cooler. Not ideal, but my power bill stays lower.

That'll pay for itself in 10 years give or take

But that's assuming your bill is that high every month when really in winter it's probably much less of a difference. But I don't know where you live to be fair.

During the day go out

During night use an air conditioned sleep pod (cheaper than cooling the whole home)

Who can afford insurance in FL?

Winter bill is usually $50-60, but gas fuels the heater. I will know the difference after this winter

Air conditioned sleep pod

You mean those eggy things, one uses to go to sleep forever and an alien plant clone of you takes over your life?

I would love to make the switch

Must be nice living in a climate dry enough for those to work.

IIRC it can also cause the structure to rot if they get the vapor barrier details wrong.

Also depends on what type of heat you use

I have a heat pump, so my air conditioner is my heater, heat pumps are basically just an AC running in reverse.

In general, my wife and I don't mind it being cold, we're willing to let the temperature in our house get down to about the mid-low 50s (F, obviously) in the winter, so we do end up using a lot less electricity in the winter. But if we tried to keep our house at a warmer temperature that most people would find comfortable, it would probably be about the same.

12.5 years.

TBF I paid even more to have my system replaced. And I think it’s definitely worth it. But will I live here long enough for it to pay for itself? I don’t know.

Just to chime in, here in Israel I've never seen an air conditioner without a heating mode. "Heat pump" isn't ever talked about because it's a bog-standard feature of every air conditioner on the market. It's just "putting the AC in heat mode".

Our summers are brutal (especially in recent years, fml with climate change) but winters aren't nearly as cold as European or American, so we don't really have much call for a whole dedicated heating system. I'm guessing this is why ACs just add heating since it barely affects manufacturing but is a massive selling point (or glaring omission) for the roughly 100% of houses that don't have other heating solutions.

It's pretty ironic that we ended up with the most efficient heating solution being ubiquitous specifically because we barely need heating.

Of course, a ton of people (including my mom) still choose to use electric space heaters in the winter. I prefer AC but I can't deny that the air feels different so it's a valid preference, if somewhat wasteful. Not as bad as gas or fire though.