[Strawbale] hello; passively cooling sb home in Arizona

[Ryan McCulley]

Hi everyone, I'm new to the list... I suppose I have to tell you since
you can't see the `Hello my name is Ryan' sticker on my shirt.

My wife and I are planning on building a small straw bale home in
southern Arizona, hopefully sometime next year. At the moment I am
researching methods to cool it. While grid power is available on our
property, we are considering a modest off-grid PV solution that simply
would not be able to operate an air conditioner or evaporative cooler.

Summers on our property routinely exceed 100 degrees Fahrenheit. Our
climate is generally arid and most of us do well with a small
evaporative cooler, which would be a great solution if it weren't for
one little problem: the monsoon season (July-September). For a period
of about 3-4 weeks, temps not only reach or exceed 100 degrees but the
humidity goes way up due to regular evening thunderstorms. It cools
off after a good rain, but if no storm comes through the next day,
you'd think you were in Louisiana if it weren't for the cactus and
dirt. Evap pretty much doesn't work in the monsoon season. It runs
24-7, indoor temperatures range from 78 at night to 86 in the
afternoon, and with all the humidity in the air, forget about using
salt shakers. You'll need a chisel if you want sugar in your morning
coffee.

I have heard of a straw bale home in New Mexico that used a solar
chimney with good results... basically it used a super hot steel roof
to pull cool air up through the house through ducts buried eight feet
below ground. You can find an illustration here:
http://en.wikipedia.org/wiki/Image:Solarchimney.jpg

Unfortunately I have no idea how to engineer a solar chimney or what
the pros and cons are (aside from not requiring anything more than a
hot roof on a sunny day and a source of cool air to start the magic of
convection going).

So... anyone have experience or information on how to efficiently and
effectively cool a superinsulated passive-solar off-grid home in a
sweltering Arizona summer?

Thanks!
Ryan McCulley