Passive Solar

Recently I’ve been developing some new bending forms and was steam bending some Gragg chair parts.  Unfortunately(?) my steam bending set-up is on the fourth flour, an unheated space with great ventilation (read: wind blows through unimpeded).  I remember filming some videos up there one winter and two kerosene heaters barely made a difference even though I was practically on top of them.  I think in a couple of shots you could see my breath; not exactly the optimal conditions for working with hot hide glue.

Ditto steam bending thin parts, where in even the best of conditions I have a couple dozen seconds to get the parts bent around the forms and fixed in place until they cool and dehydrate into their set shape.  The first recent session was on a cold, grey day and was miserable.  I found that if I timed things just right, even on a cold day, if it was sunny and the air was still I could get the work done just fine.  The reason was my 2500 s.f. of corrugated asphalt roofing overhead.  Since the roof is completely uninsulated as the sun warms the roof it then radiates much of that heat downward into the attic space of the barn.  My curiosity led me to point my laser thermometer at the roof at the peak of the solar gain — the underside of the sheathing was almost 100 degrees F!  The result was a 20-25 degree gain in heat in the space.

I fully intend to exploit this in the furute with some fabricated passive solar units.  Stay tuned.