Perhaps the simplest and one of the most easily integrated passive solar techniques for the home is the trombe wall, developed by French engineer Felix Trombe.

The Basics:

South facing (and yes orientation is the most important component of this approach) glass wall with a heat absorbing, black (or other dark colored) wall separated by an air space (a corridor works well in a design sense so as not to waste space). Holes in this wall at top and bottom. Living spaces are located on the other side of the wall.

How it works:

The sun heats the wall or you can say the wall absorbs the heat from the sun, therefore preventing it from heating the bulk of the home. The wall acts as a heat sync, absorbing the heat and spreading it out more slowly that just allowing the heat to flow through the larger spaces. The air cavity also heats up. Hot air rises (of course) and this allows colder air from the house (that has fallen to the floor of the living space) to flow through the holes in the bottom while the hot air flows through the holes in the top of the wall. This is actually called thermosiphoning. Pretty cool. At night (when there is no sun and therefore less available heating) the wall will radiate the heat back into the house.

What to watch for:

You will want to mechanically close the vents (holes at top and bottom of wall) at night. This is especially true in colder climates as the thermosiphoning can reverse and suck heat right out of your living space. It might also be beneficial to make the wall of windows have either operable windows or doors. You can even make an outdoor space on the other side and line the wall with patio doors. You do this because not every day is hot and requires you to keep the heat out. You might want to open the house up to the outdoors.

This is just a starter course on the trombe wall but I will try to keep posting here about passive strategies.

How many people use this technique? It sounds simple, low cost, beneficial and well the intuitive way to build a home. I am home shopping and wanting to go green, but I haven't seen this approach as described.

Are there ways that this is reformatted and altered to not look like what you are describing? Is this something I could do in a home that I purchase rather than build?

I am using a thermal slab in my new home and have integrated a radiant floor system. It is a combination active/passive system and I think it's going to be great.

I didn't go with the trombe wall as my best views are to the south and my architect and I decided on a scheme that didn't work with a trombe wall along that axis. The thermal slab was the compromise.

I like the idea of a trombe wall.

txgreenie, I think the best thing you are doing is the passive/active hybrid. Passive systems are great and can really knock down the cost of owning a home, but there is a limited number of approaches when you use such a system.

As you mentioned, greening the home is a compromise. You have to find your best opportunities and use them to their best ability in your situation.

Do you have any in situ or case studies of trombe walls that you can give us. I would love to see or even better, experience a home with this passive concept. I mostly trend toward the active stuff like solar hot water and PV cells but the trombe wall concept seems pretty intuitive.

This one is a little different than the described scenario, but the concept is the same

http://www.aspencore.org/sitepages/pid67.php