Solar Chimneys and Earth Architecture

It was my curiosity about passive cooling that brought me to earth architecture in the first place. A particular interest of mine in researching passive cooling is the concept of the solar chimney. It's a feature we will include in our test structure. One great solar chimney example brought to my attention is at the Hawaii Gateway Energy Center. In fact, it's not AT the center, but integrated INTO the building of the center itself. You can read more about the concept deployed here: http://www.energyfuturehawaii.org/learn-more/7-renewable-energy-a-energy-efficiency/66-thermal-chimneys-and-passive-air-conditioning-.html.

Solar chimneys and Persian wind catchers (bagdirs) are certainly nothing new. In fact, I saw a great example of a wind catcher at the Cal-Earth institute a couple of weeks ago on a visit to their site. I didn't expect to see that as part of their demonstration project and was thrilled to see a working example. Unfortunately I was there in winter and didn't get to experience how it functions in the desert heat. Our guide at the center, however, indicated that it worked extremely well to circulate a cooling breeze in the summer.

Our own Firehouse 8 has a superb set up for several solar chimneys and we'll certainly be integrating those into the passive cooling strategies planned for the building. Large ceiling mounting gas heaters used to warm the truck bays have been removed and we will be improving the vent pipes that lead to the roof to create natural convection of warm air off of the ceiling and out of the building.

Drawing hot air out, implies drawing COOL air in. That is the major design challenge we face. The Hawaii center illustration is a clever use of cold water and is a very interesting design. Simple earth tubes have been considered (nice write up here: https://www.thenaturalhome.com/earthtube.htm) but are generally discouraged for hot humid climates.

Watch for future updates on our solutions in this arena. The appeal of being able to draft a lot of fresh air indoors and improve air quality while cooling is very appealing!

Comments

[Adam]

Very exciting to see this. I'm particularly encouraged to see such business interests behind CEBs and multifamily. This is what the industry needs to complete the transfer in to mainstream building.

I'd like to see any details on the use of railroad ties, a wood joist floor(correct?) and then CEBs on the wood. Seems problematic to me. I'm all about rubble trench with CEBs, I've loaded two story double walls on them, as well as the adobe right on the gravel, but I've never seen adobe on top of wood. Your thoughts are appreciated.

[David]

Adam,

Thanks for your comment. Bear in mind this is a test structure to train the crew, work with the dirt specified for the project and to work out the design details for the multifamily project. By code, we would typically pour a concrete beam to rest on the rubble trench not use wood so you are correct. You're also correct in that we wouldn't typically set the ceb's on wood, rather a stem wall. This was a quick turnaround, small and code exempt project designed as a prelude to the main show! I'm encouraged to hear about your own rubble trench experiences. We have terribly expansive soils in the San Antonio and a dual footed foundation makes a great deal of sense here though it's not typically done. Not sure why. I'm not an engineer but stay tuned and I think that's a topic worthy of a blog post!