Solar Heaters - Thomason's trickle collector???

Since I've been working on design ideas for my future greenhouse/coop, I've been thinking about options for solar heaters. I was really intrigued by the supposed performance of the Thomason trickle collectors from decades ago but I'm a very visual person and I haven't been able to get a good handle on how they are actually constructed just from reading descriptions in articles or even his various patents. I've tried searching for other real-world examples or discussion, but I'm just not finding much. Is anyone here familiar with this type of solar heater? I did find one other example of a solar heater based on the Thomason idea but the materials and construction methods seem like they may not last very long. Is there a reason this method hasn't caught on?

An article about Thomason's solar heaters in use on some government buildings still functioning well 18 years later (article was 2003)
https://www.builditsolar.com/Projects/SpaceHeating/Thomason/Solar_Heat.pdf

Mother Earth News interview with Thomason
https://www.motherearthnews.com/sustainable-living/green-homes/solar-home-design-zmaz79ndzraw/

Links to his patents
https://www.builditsolar.com/Projects/SpaceHeating/Thomason/ThomasonPatents.htm

Instructions for modified version of Thomason's Trickle-Flow solar heater
https://www.builditsolar.com/Experimental/MTD/MTD%20RH&JC.pdf

Nothing helpful to add except I'm glad you posted this.  I hadn't heard of this before, it looks very interesting.  Another youtube rabbit hole...

Very cool indeed!
I love the low cost materials and the improved design in that last link you posted.

I think a refrigerator could offer a lot of metal skinned insulated panels to make a design like this work.

For a bigger collector, a single 4x8 sheet of foil faced foam insulation board could provide a water proof structure to build your collector on.
I think  a PEVA shower curtain might make a good inner layer instead of the clear  Mylar, but it is only good to about 180 degrees F at most.
I'm not sure how hot the collector gets.

Hi, don't know if you are familiar with him but John Canivan along with I believe Richard Heiliger developed a "Modified Trickle Down" (MTD) solar collector panel system that is more modular and scalable. There are a few YouTube videos available that he made as well. Mad hippy scientist type, I found him entertaining and his ideas are interesting.

https://builditsolar.com/Experimental/MTD/MTD.htm