The intent of this blog is to share my efforts at making ice at 50 degrees.  I am not sure their is any practical reason for my ongoing experiment other than cold beer while camping.  My interest was aroused when I came across an article about making ice in India and Syria during ancient times.  They would dig a deep dry well and place pans of water at the bottom. The water would freeze and be harvested.  If they could do it why can't I?

The theory is that we have access to the cold of space if we can control the frequency of the outgoing infrared radiation to take advantage of the gap in the water absorption of infrared.  Air currents must be controlled.

At present my device consist of an 8 x 12 inch Styrofoam box with 2 inch thick walls which is divided into two chambers.  After trying dozens of containers I have had my best results with a black PVC 4" pipe cap.  The PVC provides a pretty good infrared spectrum of radiation but is a poor conductor.  I am in Cottonwood Arizona at 3400 feet and can dependably make ice at 40 F. but only at night.  This is still 10 degrees below my goal.

I will provide a list of those things that I have tried and hope to try in a future posting.  Here is a good link:  http://www.asterism.org/tutorials/tut37%20Radiative%20Cooling.pdf.

Here is a list of common materials and their emissivity:  http://www.infrared-thermography.com/material-1.htm

Here is a description of the infrared window:  https://en.wikipedia.org/wiki/Infrared_window

I would appreciate any advice you may have.

Charlie