Trombe walls at work

Passive solar heating is a neat way to warm your house and reduce your electric bill without having to install solar panels.  In fact, passive solar design is a hot topic among homebuilders and remodelers.  Oftentimes, passive solar design elements such as landscapes and awnings can be incorporated without the need for an expensive remodel.  So, you can be cheap and go green – all at the same time!  That’s the name of my game.

Among the various methods and materials required for efficient heating and cooling using passive solar energy are Trombe walls.  Trombe walls are a specific type of passive solar wall that should be installed on south-facing sides of the home or building.

Trombe walls are generally between 8 to 16 inches thick, constructed of masonry materials (brick).  For the most efficient heating, they should be positioned between the sun and the primary living area.  Outside the structure, a Trombe wall looks like a window constructed over the wall.  Glazing of the window traps heat when sunlight strikes its surface.  Then, overnight, Trombe walls will slowly distribute even heat through vents built-in.  In short, Trombe walls act as a large solar thermal collector.

Trombe walls are named for the engineer Felix Trombe, who took the idea from an 1881 patent and made it popular with the construction of a passive solar house in France in 1964.

Another type of Trombe wall is one in which individual window panes are filled with water.  In fact, water offers a faster heat exchange than masonry. Estimates are that water walls in a passive solar design can save up to 90% in heating and cooling!

In the following video, a contractor demonstrates the efficient passive solar heating achieved by use of a water Trombe wall:

Fish in your solar wall?

For the truly ambitious, you can put fish in your water Trombe wall.  No kidding!  As a (former) goldfish owner, I can definitely say that you need to make certain that any fish you allow to live in your passive solar wall tank can tolerate heat, for example, tropical fish.  And, just to make another absurdly obvious statement, remember to build in a place from which you can feed your fish and clean the tank.  Your best bet is to hire a contractor that specializes in solar construction – and also knows a bit about fish!

Even without fish in a water Trombe wall, you’ll need to change the water from time to time and balance it with chemicals to keep algae growth down.  Can you imagine a better conversation-starter than a water wall in your home?  Of course, if you add finned friends, they can offer you a whole new angle on a “fish story.”

I don’t know, I can imagine putting in a Trombe wall at my house, but probably without fish. Then again, the entertainment factor of watching my cat be tormented by the trapped fish may be worth it!  What do you think – are you game for a fish-filled wall?