Passive solar chicken coop for the desert?

Hi everyone,

I've just signed up with this community because I have a burning question (excuse the pun)-- how can I build a passive cooling system for a chicken coop that will keep the hens reasonably cool during a scorching desert summer--one that doesn't use much water? I'm planning a coop in Las Vegas, but, being concerned about the safety of the (prospective) chickens when our temperatures reach the triple digits in the summertime, I'd like to plan our cooling strategy ahead of time.

Here is my idea thus far, and please feel free to shoot me down if this won't work: an earth-filled South-facing cinderblock Trombe wall with a built-in window to ventilate the underside of the coop, with an awning extending over it from the coop/run that will limit summer sun exposure. I'd like to paint it and incorporate a planter to pretty it up a bit, and build a window in towards the top to ventilate the coop itself as well.

I have read that Trombe walls can actually have an overheating problem, and that the best way to maximize cooling and encourage ventilation is to insulate the interior of the wall, so I was thinking I could staple foam board onto the wall, between it and the coop.

Thoughts? Concerns? Sage wisdom?

I think it might cool better by eliminating the window in the wall. Ventilation can come from the sides and back. A double roof or shade cloth suspended over the coop roof might help as well.

If you aren't set on a completely passive system, you could use the geo-air system that some of us have been discussing recently.  While not completely passive, it does use only a fan.

We used a little solar fan one year and it seemed to help.

You used a solar fan for your chickens? What kind of climate are you in? I'm just concerned because it can get SO hot here and I work full time, so no one would be checking on the chickens during the day. I have to make sure my hot weather plan is foolproof even when I'm not home.