Richard's collectors are entering their third winter season -- this is his report on how they are doing.
The full story on Richard's Modified Trickle Down collectors and full construction details...
Winter 2011 MTD Update:
Fall 2009 MTD Update:
Seeing the first snow of the season in the mountains today finally provided the incentive to write a short update on the steel version of my MTD collectors. Yesterday it was 85 *F and today it is 45*F, and the 145 *F I had in the tank yesterday evening is keeping me warm today. I have found that even with the small 100 Ft^2 set of collectors I am nearly 100% solar heat in the early fall and late spring.
I am going into the third winter with these same collectors. I have done virtually no changes to the design. They are as functional as the day I installed them. Since I made my own differential control for them I have played with the control, but the system remains the same since last year. In fact I left the same water in the system for the entire last year. From looking at the sight glass I have lost only about 25 gallons thru evaporation thru some of the small areas available. I have seen absolutely no indication of algae growing in the water, and have drained a bit to look at it, and it is still clear enough to think you could drink it, NOT!
Over this last summer I left the system running, just as if it were still heating season. I have the tank enclosed in a wood box with two layers of R13 fiberglass to insulate. There is a removable panel on one end of the tank enclosure. I removed the panel for the summer. Left the outside door to the sun room open to vent the heat during the day, and further cool the tank overnight. I noticed that the room just behind the collectors stayed a great deal cooler thru the summer. I believe that running the collector during the day and dumping the heat overnight, helped keep the house a bit cooler, and reduced the load on the evaporative cooler I use. With the high summer sun the water temperatures did not go nearly as high as I would have thought, seldom over 155 *F at the end of the day.
The Mylar (polyester) is still clear and shows no sign of deterioration even after stagnating all last summer and running all this last summer. The gutter seal has shown no sign of leaks at all. It is looking promising that I have found the right combination of materials to have a MTD system with longevity.
A new link for mylar.