useful comparison for those with or building solar kilns

[MattJ]

Thought I would share an experiment and upgrade.  Based off Gene's publications and advice I was looking to upgrade the covering on my small solar kiln.  The plexi after under 2 years was starting to show cracks and also was a single droopy layer.

I was able to order double wall polycarb greenhouse covering for about $150 total.  I decided to do an experiment and find two similar days of weather and run a temp log for the last day of the plexi and the first of the new install.  The probe was at the front of the stack, mid-height where the incoming solar heated air comes in. There was a load of red oak and maple, about 500 bf, which is max capacity for my kiln.  It had been in for a week and was 16-18% incoming (air dried under cover 1.5 years).  Vents were slightly opened as these were air dried.

My kiln only gets half a day of direct sun where it is currently at, but suits my needs.  The attached pics are the weather in the area (pretty close to similar sat and sunday).  Saturday was the plexi, sunday was the polycarb.  Both days has some light scattered clouds until about ~12:30.  Full sun is from around noon until you see the temp drop.  The humidity is from the outside air, and the temp is the twin peaks chart.

Hope this is helpful for those considering options for glazing.  I am really happy with the polycarb.  A boost in temps, much lighter, and much more rigid and easier to install.  Cost under $200 with all hardware, delivery, etc to do a 6x10' collector.

Thanks for your help Gene!

Matt

  

 

[AnthonyW]

What was your source for the double wall poly carb?

[scsmith42]

Very insightful information Matt!  Thanks for sharing.

Ditto the question re where did you source the poly-carbonate?

[MattJ]

Hi guys

The company is called greenhouse megastore out of Illinois.  Just google it.  They sell large sheets which have a decently high shipping fee, or 2' wide easy ship panels that get to you via ups in a few days for a very low shipping cost. I was pleased with their service and the panels are very rigid and light weight for moving around. If you get the panels pay attention to which side is labeled for uv exposure.

[GeneWengert-WoodDoc]

I saw some at Home Depot