> I've lived in dwellings in developing countries better capable of managing summer heat than most Bay Area apartments.
Developing recently has its advantages. They’ll install reversible AC mini-split systems primarily for cheaper heating than gas/oil/LP, but with the side-benefit of AC.
Then again, a lot of Western Europe (hello France!) won’t use AC because “air conditioning makes you sick”. I’ve even seen it unused in a car during a heatwave for this reason, and it wasn’t an economic issue.
Here in the UK we don’t generally use A/C not because of health concerns but because there’s only about three or four weeks of the year we’d actually need it so in practice fans and complaining heavily during those three or four weeks does just fine. Our climate is generally damp, grey, and mild; the summers don’t get very hot and the winters don’t get very cold.
This might change with climate change though, I suspect in the future we’ll need better cooling and better heating if the jet stream gets interfered with. We’ll also need better drainage but there’s no shortage of scummy housing developers putting their underbuilt and overpriced shoeboxes on flood plains.
Even mildly uncomfortable heat can effectively waste 10% or more of the time you spend in it. And that number rises pretty fast as the heat increases.
So even if you remove discomfort from the equation, it doesn't take many tens to hundreds of hours of heat to justify a £100 air conditioner that costs £0.05 an hour to run.
We’re finishing the gut renovating a house in the south eastern US were you definitely need both heat and air conditioning over the course of the year.
We tore out our central hvac system, all the equipment, all the ducting and replaced it with mini splits.
They are sooooooo much better. More effective, more flexible, and cheaper. Heating bill cut by 2/3. They let us heat and cool each room independently. No dust,smells, or heat gets moved between rooms. They even have a dehumidify setting.
It is moronic that something similar is not standard practice in homes.
What's your fresh air system? My current home (in a mountain state) has problems with CO2 buildup with its central air system, so I'm curious what people with minisplits do to handle CO2.
Good question...a couple nested systems. Noting that the house was designed to be 'a passive house' (air quotes) in the early 1980s so it has some quirks.
1) we have a large stove so needed a makeup air fan anyways to match the hood. I worked with them to design the makeup system so it is quiet and pressurizes the second floor 'landing' and is larger than necessary...rather than just immediately pumping air into the exhaust.
2) We also have high ceilings because of the shape of the house (it...should help?)
3) the high ceilings also have remote openable skylights (originally they had hand openable crank skylights) that are already really affected at releasing any heat buildup
4) an excess of windows and two multi-panel sliding doors which, because we are only heating and cooling rooms when they are occupied, can be kept open more frequently. All of them are under deep overhangs and 75% of them are south facing so they are great at managing solar heat gain and we can open them often.
I'm curious how it will work and we have some backup plans. We're putting CO2 monitors in the bedrooms and the kitchen when we move back in and if needed a bunch of the systems can be connected to home automation rules if needed. Even the exhaust fans for all the bathrooms are on the home automation system already.
We lived in the house for about a year before rennovating it with 2 mini splits retrofitted (long story). It's 1900 square feet and we both worked from home. At night, we heated the bedroom, during the day we heated the office. During winter the sun heated the rest of the house. Our total power bill was around $70 a month.
Any airtight home will require a heat exchanger to provide the necessary ventilation. The source of heat or cooling doesn't matter. (Wood stoves and furnaces require make-up air, which should be supplied directly, not by infiltration.)
Developing recently has its advantages. They’ll install reversible AC mini-split systems primarily for cheaper heating than gas/oil/LP, but with the side-benefit of AC.
Then again, a lot of Western Europe (hello France!) won’t use AC because “air conditioning makes you sick”. I’ve even seen it unused in a car during a heatwave for this reason, and it wasn’t an economic issue.