Bob, thanks for the links. Tim, thanks for the humor.
I asked the question to the tech folks at Radiantec and they replied with the following. I think if you could somehow use the surplus summer heat to generate electricity you would have a really sweet solution.
@unknownuser said:
Thank you for your recent visit to our website. We design the system so that the panels are mounted at an angle that most effectively captures the winter sun that passes lower on the horizon. During the spring, winter and fall we utilize a high temperature override control. When the system temperature gets too high this control will turn on one of the radiant pumps and circulate water through a zone even if the thermostat for that zone is satisfied. With this detail we are storing the extra heat within the envelope of the home.
During the summer when the sun passes over higher in the sky the panels are not making as much heat. We hope that much of your domestic hot water can be heated by solar during this time. If the system temperatures get too high and no domestic hot water is being consumed than another type of safety control is used. This control is referred to as a Heat Dump Valve. The Heat Dump Valve is attached to the domestic hot water line and when activated by a high temperature reading it allows some hot water to be drained from the system. This action allows fresh cold water to flow into the system cooling it enough to allow the panels to once again begin working.
A newer feature that Radiantec has designed for prevention of over heating during times when extra heat is not desired in the home is referred to as “Garden Root Zone Heating”. All though this is a manual valve operation it is a great way to rid the system of excess temperatures. The idea is to bury tubing under a garden area. A valve can be opened to allow heated solar fluid to circulate through the garden zone which could very well extend your heating system in the later fall months.
