I know of a few locations where it would be nice to have passive solar hot water in the summer. I have noted that a black garden hose in the sun produces hot water. The hose could be placed on a roof. The problem is getting this heat into a storage tank passively. The hot water tank would have to be mounted higher than than the hose. I would like to employ the ordinary basement hot water tank. Hot water rises and will not go down to the basement tank.
Is there any fluid that sinks when heated? Can a dissolved gas be somehow employed to make hot water sink? Any ideas? Frank Znidarsic
