Herewith the latest show of my new solar hot water heater. Its designed life span is 50 years or more and it weighs 450lbs including water. All materials are non ferrous.
The water pipes are 42mm copper and I designed for eight, changed a measurement and managed to get nine pipes in the box. The pipes are floating and rest on various pieces of dowel - hence the freedon for movement. Total water capacity is 7.6 gallons or about 34.6 litres.
The insulation is 25mm Kooltherm (polyisocyanurate)sheet which is doing well in the heat.
Temperatures recorded on dry pipes during the installation were 89.9 Celsius, and in the last day or two with pressurised wet pipes 79 Celsius has been observed. I expect higher temperatures.
The unit is fitted with 4 internal sensors which are hooked up through an RS232 interface to my computer. They are:- Inlet pipe, Centre pipe, Outlet pipe, Internal air temperature, and external ambient temperature. The data is dropped into a running Excel file and I am very impressed.
The data has also shown me some short comings in the design especially what happens when cold water is brought into an already hot solar box. As result of this I intend to add more insulation and make a dedicated insulated box for each pipe. I will upload this modification and the results at a later date.
The photographs should be self explanatory, but if you have questions please ask.
Dave HK