Point of use home utilities are much more common in Asia.

[randomness]

For example, the standard home air conditioning solution is the mini-split, or ductless air conditioner, one to a room. This kind of air conditioner has an outdoor compressor and an indoor air-handling unit, with a thin tube for refrigerant connecting the two. In most of Asia from Beijing to Singapore and everywhere in between, this kind of air conditioner is the kind you encounter. There's always a remote control so you can adjust it from the comfort of your bed or your TV couch.

This appears to be the preferred way to do climate control, even in the most expensive of houses. Each room gets an air-handling unit. Multiple air-handlers can be attached to a single compressor, and the holes through the walls are quite small, so the system is quite flexible.

It is the height of extravagance to leave the thing on when you're not in the room. Even very rich people shut off the air-conditioning when they leave the room, and turn it back on when they come back, so they are only cooling the rooms they are in. The air conditioners are quite powerful and lower the temperature very quickly, even in places like Thailand or Singapore. This also means that the hallways between rooms can sometimes be quite warm.

As for water heating, the vast majority of water heaters in Asia are point-of-use. The modern ones come on automatically when you turn on the hot water, and there's a lag which is shorter than that one expects from a central water heater here in the States.

I've often thought about implementing this water heating solution here in the States, possibly combined with a central water heater somewhere to bring the water temperature from cold to warm before it reaches the point-of-use heaters, but not so hot as to lose significant heat along the way. digitalemur says that this idea would work best with a low-cost central heating system, like a solar water heater.

Comments

[docorion.livejournal.com]

Europe uses a similar water heating solution in some cases, but generally a more central one where the heating unit is central, and heats water for the entire house at time of use. (We called it a geyser, but I've seen them in the US as "tankless hot water heaters").

The point of use cooling idea is terrific; I wonder if there's a difference in installation price, though? Because it would be just like the US to skimp on initial cost and pass it down onto cheap utilities (since US utility cost is usually lower than comparable cost elsewhere). (Yeah, I know, it's the rational thing to do economically, but it ignores all the externalities I care about, without any countervailing virtues I don't (other than "cheap", which I value only if paired with "good").

[karakara98.livejournal.com]

Now we're talking my language. I have too much to say and too much to do to make comments in this post worthwhile. I'd love to discuss this further with you over a beverage or an ice cream!

[denyse.livejournal.com]

Yeah, coming from Singapore the idea that one would air condition one's entire house all the time still seems horribly extravagant. Esp when you're out of the house.

[totient]

I've seen a lot of point of use water heaters in Latin America, too. Perhaps the difference is that in the US, many hot water systems piggyback on the central heating system, whereas in warmer climates you probably don't have a central heating system.

Preheating hot water is by an enormous margin the best bang for the buck for solar energy systems. The equipment costs very little and the energy savings is quite significant.

[mangosteen]

You see occasional advertisements for mini-split systems in New England, where you have 100+ year old houses and no desire to retrofit ducting. I've actually thought about it a few times, since it would actually be pretty efficient and clever.

There's a chicken-and-egg problem, though. Since people don't typically have them, they stick out in a home environment, which means that it's a liability when trying to sell.

[nathanjw]

The air conditioning thing is interesting. I've been looking into retrofit AC options a bit lately, and aside from the ducting technology (high-velocity seems to be the way to go in retrofitting an old New England house), there's a lot of emphasis on getting the compressor sized correctly for the house size and heat load (sun exposure, number of windows, and so on play into this). It is frequently pointed out that getting too large/powerful of a compressor will only cool the house in short bursts, and that that's not good for getting rid of humidity - you end up with hot and humid alternating with cold and clammy. In fact, the theoretical ideally-sized system runs steadily, not in bursts at all. How was the humidity in these places?

[whitebird.livejournal.com]

These air conditioner units are getting more prevalent in both residential and commercial usage in the US, or at least out here. I know a few people who have had them installed into room additions in their houses, and the air conditioning contractor for the college retrofit two small units for spaces where the regular A/C was sub-optimal, and then cut off the regular air flow.