It wasn't actually spending time in Himachal Pradesh in the early spring that got me thinking about this, but that's probably pushed me to keep it in mind on a regular basis, since "summer" hasn't fully arrived here yet.
It is, in fact, the presence of air conditioners that brings this to mind as I hear of friends and colleagues in Bangalore (and elsewhere) turning to Freon to manage the summer heat.
We have the same difficulty in the 4440 cabin. The sleeping area is upstairs in a just-tall-enough-to-walk-in loft. A neighbour across the cove visited us last year -- it was the first year we'd both been there in the same month -- and spoke at length about energy efficiency of homes, as that was his day job. We were discussing insulating the walls (since that would allow us to start installing shelves and countertops) and he strongly advised against it. In his mind, the cold of the early spring and late autumn were best beaten by ceiling insulation. Likewise, the uncomfortable heat was best fended off by the same ceiling insulation. Insulated walls are a good idea... but sort of a luxury, in comparison.
I started looking at passive temperature architecture last summer, out of curiosity. The cabin is too far-gone... we can't really do any kind of passive heating or cooling in its present location or construction. But the idea makes a lot of sense and requires very little active energy: suck the air from the bottom and blow it out the top -- or vice versa. In a lot of cases, an array of small CPU fans might do the trick and as an added bonus, many of them are 12-volt.
There's a real utility to basic differentiating construction techniques that I've never fully appreciated until recently: Historical methods of architecture almost always involve low ceilings in cold climates and very high ceilings in hot climates. Variably, the hot climates often also include some variety of passive air movement as well: the vertical passive wind tunnels of narrow Japanese city homes or the breathing inner courtyards of South Indian bungalows.
There is always, of course, the sun. South-facing insulated windows provide light and heat both -- but the drop which corresponds to winter seasons is inconvenient at best in cold climates. Passive energy is very hard to do **directly** and an intermediary is often a better first thought.
In the world of energy, this is of course energy storage: Batteries and hot water tanks. Since a good solar hot water setup works even in -30C, it is the insulation of the water tank that makes all the difference. This is where hardware hacking comes into play. How far are we from household installations of aerogels? And how far from that point to creating them on our own? The same insulators which protect hot water from going cold could potentially protect a home from temperature variation as well.
Those of you who've heard me ramble on the subject know that I'm more or less completely in love with mineral wools -- the recycled waste from steel factories which can be formed into standard-sized insulation batts. They are fire-proof, water-proof, do not rot, do not encourage the growth of molds, are not made of plastic, are largely non-toxic (I say "largely" because they're not very fun to install but they're safe for the end user), and never sag or compress.
They are also very expensive.
This is one of those early investments, however, that feels like it would pay big dividends in the long-long run. We know what a comfortable house feels like and the next generation (and the next and the next) are unlikely to come up with some exacting physical standard which is higher than the Level 4 comforts we know today due to some magical new technology. It's a lot more likely that we'll asymptotically approach zero (external) energy consumption for homes, which in extreme climates can make a substantial difference to human impact on the environment... and on energy dependence and the focus of the economy.
A microcosm for this early investment is a great thermos. Even an inexpensive metal thermos which insulates by vacuum keeps liquids hot all day in cool climates. No one is overturning the climate crisis because s/he invested in a good thermos for tea. But it's fun to think about how this flattens out our individual power consumption curve -- and then scale that up to the household, neighbourhood, village, city, and state level.
Blankets, clothing, rugs, slippers (the fuzzy kind), "house wrap", really fancy windows, wood stoves, centrality of a kitchen (which is often quite warm from the use of a stove), fans, nearby clusters of trees, passive water-cooling mechanisms, and so forth are all much more mundane (but far more accessible) aspects of passive energy worth considering in our architecture choices. For example, classic Japanese construction encourages passive water-cooling by simply throwing a bucket of water on the pavement in front of the house and leaving the windows open so evaporation creates a draft. Obviously in a Hacker Village automation will be preferable to baked-in manual rituals but it seems fair to say that such manual behaviours could be optionally automated.
Something I've been chewing on lately. I'd be curious to know if anyone else has other approaches to the passive energy problem.
I hope everyone's home is a livable temperature right now, given that we're all stuck inside for the foreseeable future.
<3
-steven
Steven Deobald