15 Sept : I travelled down to Oxford to visit Ice Energy, and to talk with David Atkins. We debated whether to use a single 1.8 x 2.0m IVT Kompact Kollector panels of plastic piping (which he has already tried out, fixed to a handbuilt metal frame), or to use a pair of 0.8 x 1.35m Solar Focus swimming pool heaters (that he has recently acquired for testing).
We decided on the Solar Focus panels. They are handier to transport and rig, and would be more likely to be used by a householder copying our idea as part of an add-on to a Heat-Pump installation. We do not know whether 2 or 3 or 4 panels would be best, but that is not the point. We are proposing to create a rig and get data from it. If after a full season, it appears to work, but could work better, that is the time to decide if we add 2 more panels - 2 will do as well as 4 for the present purpose.
During the day, I had a short phone discussion with Andy Sheldon, MD of Ice Energy, who has agreed to let me have the panels and the fittings, and we shall be partners with Ice Energy in seeing how this system will work. We are paying the plumbing, electrical and labour costs, and hopefully, the university will provide something in the way of dataloggers.