Mamachari aside, from Ask John:

For example, contemporary Japan places a fairly heavy emphasis on consciousness of the greenhouse effect, leading Japanese homes to exclude central heating and Japanese residents to hesitate running their “aircon” air conditioning systems for fear of depleting the ozone layer.

Really?

Since 3/11, isn’t the point of cutting back on AC to save electricity, since there’s a shortage? And the central heating thing… I’ll cut him some slack because he lives in Florida, so he probably hasn’t had to pay the heating bills for a New England winter, for a house over 90 years old…

What I do want to know and discuss is the nature of conservation in the Asian consciousness in light of the question being posed: why do Japanese homes use space heating rather than centralized heating? Well for one, my hypo is just common sense: it’s a matter of cost and economic development in terms of construction of private properties. Old houses don’t have central heating (or cooling) by default, so there needs to be some incentive for people to add them. in the US, old houses have central heating/cooling often because it’s the law, and also because nobody would buy such a house without central heating and cooling. Central HVAC is considered a standard feature in single family homes today, and even in most apartment housing. It’s less so for single-room apartments and dorm rooms, since it also makes sense to just use room-size heating and cooling solutions in those cases. Of course, in general, good, up-to-date HVAC solutions will save energy AND money in the long term than relying on portable space heating and cooling. But this is balanced by the nature of space usage in that heating and cooling compartmentally saves energy because you are only warming up or cooling down the room of the house you are in, and for most people (especially nuclear families with few/no kids, and singles) they tend to stay in the same room the whole time they are home, like 95+% of the time in the same room. You might get up to go to another room many times, but in terms of time spent it’s pretty extreme. Of course this is not even true in some cases, such as rooms with high ceilings or very efficiently designed HVAC systems, but usually that’s the case.

So here’s the funny thing, space heating is probably a lot more efficient, from an energy use point of view, in places like rural Japan or suburban America, because space is plentiful and houses are bigger, with more rooms. In urban Japan it makes less sense because your 4.5 tatami dorm is pithy small to begin with, it’s not a whole lot more power to heat up 4 or 5 of them versus what you can save in terms of energy efficiency by using a larger scale HVAC system. If you live in a flat or something, space heating gives you the option of controlling the local temperature to what you like, but it’s overall less efficient. Unless, I guess, an apartment building don’t have full occupancy and then space heating will save, under some breaking point of occupancy.

I suppose this could also be a matter of practice and customs. Like, paying your rent, managing your power and gas bills, and not paying for a management fee that goes into HVAC costs. So here’s another theory.

Anyone actually knows how it is and why it is? I’m thinking new houses in Japan have HVAC as well, simply because today’s technology in heating/cooling is so much better than off-the-shelf solutions that a central system just make more sense. I guess there are single-room solutions that are also very efficient (and probably largely sold only in Japan/East Asia). And it isn’t even a gas/oil/power issue, since most East Asian housing have some kind of gas delivery system baked in, unless we’re talking about rural areas where people still get canisters delivered to them.

Of course, western-style and modern housing built today probably has HVAC built in, even in Japan. There’s also the philosophy about warmth as something regulated via the individual rather than heating a space. But I don’t know what is more likely true than not. Green…I don’t think that one is particularly right.