Comment by sn41 | Hacker News Reader

Comment by sn41 | Hacker News Reader

I live in a small "flat" in India. Without A/C in the summer (only at night), our consumption is ~200 KWhr per month. With A/C only in one room for something like 4-5 hours per day, it shoots up to ~500 KWhr per month. Indians switching to A/C on a big scale will be a disaster for the world.

I believe that the answer lies in architecture, not in more energy-intensive devices which may or may not actually work (this one fools the body - that could be catastrophic, increasing chances for a heat stroke). India was always hot - but older buildings used to be built (1) with high ceilings (2) with cross-ventilation.

http://www.architecture.com/SustainabilityHub/Designstrategi...

This contrasts with buildings in cold countries, where buildings are insulated against winter. In the name of "better" buildings, Indians are switching to sealed buildings working with Central A/C. Blind imitation.

On the other hand, there were builders committed to "environment-friendly", low cost buildings (not the modern scam of "green buildings", which are actually more expensive.) Laurie Baker in South India was one - a real unsung, and now forgotten hero:

http://en.wikipedia.org/wiki/Laurie_Baker

http://www.hindu.com/folio/fo9908/99080300.htm

What's particularly sad is how the vernacular architectural features, which have evolved over thousands of years to deal with these issues, have been largely abandoned over the 20th century. Only to be replaced by ugly concrete buildings and AC units. These include the Malqafs[1] (windcatchers) once found all over Arabia, Egypt, and Nubia. Also the use of underground streams[2] to cool buildings. And generally not building huge south-facing glass windows when you live in a place that reaches 45°C in the summer...

Also, a personal architect-hero of mine is Hassan Fathy[3]. This man inspired generations of environment-friendly architects.

[1] http://en.wikipedia.org/wiki/Wind_tower [2] http://en.wikipedia.org/wiki/Qanat#Cooling [3] http://en.wikipedia.org/wiki/Hassan_Fathy

Thomas Jefferson designed his bedroom with ventilation in mind.[1]

[1] http://www.monticello.org/site/house-and-gardens/bedchamber

Is it realistic that you could find an underground stream wherever you want? Around 20 million people live in Mumbai. I'm just not sure it would work on that scale with tall residential buildings, as awesome as it is.

These tunnels were man-made. But yeah, obviously the scale these worked at was more towards villages and small towns.

It's sadly part of a growing faddishness with "Western" technology and developments. I find it quite sad because the local solutions are often quite elegant.

In Korea for example, they have clever traditional windows that open like normal windows, but also draw up completely and hang from the ceiling, turning your house or other structure into a pavilion. Large roofs provide lots of shade.

In the winter, you literally light a fire under the floor of the building and radiant heat warms the entire structure.

Some of these things carried over into the modern age, but many sadly did not. They're remarkably comfortable and energy efficient dwellings.

http://www.youtube.com/watch?v=kJ21SchGpsQ

> In the winter, you literally light a fire under the floor of the building and radiant heat warms the entire structure.

Yeah, and occasionally die of carbon monoxide poisoning.

http://www.ncbi.nlm.nih.gov/pubmed/22948168

> And generally not building huge south-facing glass windows when you live in a place that reaches 45°C in the summer...

People love south-facing rooms with giant glass walls in Japan. I asked several people about it and the most common (sensical) response that I got was that it makes it much easier to do laundry since people hang things out to dry.

Old homes (pre World War II) built in the southern United States all are centered around high ceilings, cross-ventilation. The home I grew up in wasn't air conditioned, and the summers, while nowhere near India's level, are extremely humid (90% plus most days) and are routinely above 90 degrees F.

The drawback in this is the cultural need for privacy that seems to have developed in many modern countries. People want to be able to shut their door, and this interferes with the cross ventilation. The whole "separate rooms on separate floors" also drastically hurts this concept. My house was reasonable, but my bedroom was tucked into the roofline on the top floor. It was unbearably hot, so my brother, father, and I would sleep on cots on a screened in porch.

> People want to be able to shut their door, and this interferes with the cross ventilation.

Go back a little further (1850-1900-ish) and everyone had doors that look like http://makingitlovely.com/wp-content/uploads/2013/08/MG_8405...

These work great with assisted convection. Open an attic window. Place a box fan in the window, blowing outwards. Everyone opens their windows and the hottest air in their room (at the ceiling) is drawn out through the door vents. It'll even work in single-floor apartments. Since getting a box fan (12 years ago) I've no longer needed AC to sleep at night.

Roofing also plays a part in cooling your home. The old cedar shakes roofing systems are naturally porous and enable ventilation.

Unfortunately, most people forget about this when the re-roof with asphalt shingles and rubberized underlays. The combination of the two lock in the heat.

Of course, cedar shakes tend to catch fire very easily in dry climates…

I grew up in a Florida home built around 1900, and we had no central air-conditioning until I was in my teens. The house was all windows, with 12 ft ceilings, and had even been fitted with an attic-fan, which is a kind of central fan circulation system that draws air in all the windows and pumps it out through a dormer window in the attic.

Privacy had nothing to do with our desire for air-conditioning. In fact, most of the doors in our house were removed because the house was used as a day-care for children prior to my parents ownership, who never bothered to put the doors back on. We grew up with very little concept of privacy.

We loathed the Florida summers. I can remember plenty of sleepless nights, lying awake in bed, sweating through my sheets. We wanted relief. That's all we wanted.

Anecdotal observation: I just checked my monthly consumption since the beginning of this year and it averaged to 154kWh per month. I'm in Finland, I live in a flat and we have an electrically heated sauna that we use on a regular basis which isn't exactly very energy-efficient and, to think, we don't generally try to minimize the consumption of electricity at all, really.

Just wondering, what sort of consumption does that 200kWh include?

I am as baffled as you are, which is why we started keeping track of monthly readings. One of my acquaintances has a store selling electrical goods, and he too was very skeptical. We have a refrigerator, an electric cooker, water heater, TV, a PC, and other usual stuff. I used to leave the water heater on in the winter months. A faulty thermostat in the water heater is my best guess. I'll try this hypothesis out this winter, and probably buy a new one in summer. Anyway the possible culprits are few, so hunting it down should be easy.

(But the A/C unit's consumption is believable - it is rated at 1.8 units per hour, so around 5 hours usage for 30 days should push the usage up by 300 units.)

Very true. I visited New Delhi in December and noticed how heating/AC wasn't built in to the buildings yet it felt normal to just bundle up/unbundle up depending on the temperature. Getting rid of boilers and only boiling water when you need to is another approach that helps with energy cost - especially if they get smarter and can predict usage (on in the mornings, off when people are out of the home, etc).

Also, paint roofs white, not black.

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