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Comment by carlob | Hacker News Reader

I think another solution that is often overlooked in the US is the passive flow caused by open windows. I've been to so many buildings in the US where it's impossible to have windows wide open and in some cases open at all.

I tend to think this is a bit like suburbia: a design choice made when energy was much cheaper.

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When we visited the island of Vieques, Puerto Rico, we stayed at the Hix Island House[0]. This facility is marketed as being "green" in general and all of the suites are cooled exclusively by wind.

This is easy to accomplish at their location due to a prevailing wind from a predictable direction. There aren't really "windows" in the building at all - rather there are two garage doors at opposite sides of the suite which can be opened to allow the wind to flow through the entire building unimpeded.

We went at the height of summer when humidity was very high and daytime highs were > 90F, and we never found it uncomfortable. And despite large numbers of insects on the island, the strength of this wind was adequate to keep them from bothering us.

The truth however is that this technique is very region specific. Windows are less effective in areas with less wind, obviously, and in areas where the wind doesn't flow in a consistent direction it can be more difficult to implement a design to accommodate this fact.

Adding fans can supplement this technique in areas with less wind. However, if you have high humidity as well as high heat, a small breeze is unlikely to be adequate; you need to move a lot of air if it's both hot and humid. While the Hix House design worked well in PR, I am sure that the typically calm, humid, hot air I encounter in a southern summer would be far less comfortable.

At my own southern home, built in the 1920s and long before suburbia and the rise of residential air conditioning, we have windows on all sides as well as ceiling fans. However, I cannot approach the comfort level I experienced in PR at similar heat and humidity levels - without, of course, turning on my air conditioning.

[0] http://hixislandhouse.com/

That basic design is common in southern Florida and the Caribbean. The Florida-style house has a central breezeway, which is basically an unobstructed path from the front wall to the back wall. The front wall has a large bank of awning windows, while the back wall typically has a multi-panel sliding glass door. When both are open, it creates a draft through the house that not only cools the breezeway but also the other rooms.

I've heard some fascinating stuff about passive airflow architecture. The floor plans of old buildings were often laid out in very specific and sophisticated arrangements designed to take advantage of local prevailing winds and weather patterns so that opening certain pairs of windows at certain times of day would effectively ventilate the entire structure. It's interesting to also think of the secondary effects we've lost by effectively sealing out the outside world and living in a closed box.

I would love to read a book on this: How far can you get relying purely on design and structure, not technology. "Passive" solutions, as you say. A fascinating topic.

Earthships, if you are unfamiliar with them, are a great place to start: http://earthship.com/

100% passive is possible today.

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

Very cool, thanks to you both!

two of my favorites...

Thermal Delight in Architecture

http://mitpress.mit.edu/books/thermal-delight-architecture

Commonsense Architecture: A Cross Cultural Survey Of Practical Design Principles

http://www.goodreads.com/book/show/4584732-commonsense-archi...

100% is very feasible, even without going the Earthship route. Mostly it has to do with extra insulation but there are a couple other techniques that help. The reason more houses aren't like this is because it adds $10-20k to construction costs so developers don't bother.

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

Lincoln Castle prison (in the UK) used passive cooling, there's a Time Team documentary about it - the jail fever outbreak section talks about it:

https://www.youtube.com/watch?v=Pm6A9sNXnzw#t=2013

(The entire documentary is fascinating, assuming you like archaeology / history of course!).

The article also suggests this is due to comfort regulations about airflow, which were originated by the heating and cooling industry and so are not likely to be friendly to methods that don't involve their products.

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