Solar Air Heater

This is a picture of the 24x4 foot solar hot air collector that i fabricated from gutter downspouts, common lumber, foam board insulation, and some corrugated glazing material.  All of these items were purchased at a local big box type lumber store.  It is essentially a dual pass hot air system that runs the length of the collector (within 4 gutter downspout tubes) and than enters a plenum where it turns and makes another 24 foot pass before entering the home through insulated ducting.

You can see the downspouts and the plenums in the close up image.  I use an in line radon mitigation fan that is actuated by a thermal snap disc inside the collector.  When the collector temp hits 110F the snap disc closes and turns on the fan and will run the fan until the temp in collector hits 90F.  The radon fan is centrifugal and is quite powerful and rated at 140F.  (http://www.suncourt.com/Centrax.html).

I keep this system up and running from late September into April.  It is piped into two floor registers in different areas of my main living space.  It regularly runs at 120F output and will generally run 6 hours per day, when sunny.  Of the three systems i have (PV, Thermal, Air) it is the least prone to shading effects.  This system combined with a high efficiency wood stove provides roughly 95-97% of our heating needs in the mtns of WV.