Deciding if I should build this solar heater

Author	Message
Murphy's friend Guru Joined: 04/10/2019 Location: Australia Posts: 678	Posted: 05:20am 11 Apr 2021       Google found me  how these heat pipes work :heat pipe Its a good read and there is a reference for the solar application discussed here about 3/4 down the detailed descriptions. Basically, using distilled water in a vertically oriented copper pipe seems to me the easiest way for home construction. No internal wick required if kept vertically, thermo- siphoning does the work then. I would fit some kind of one way valve to allow evacuation of the air, fill the pipe half full with water and soft solder a copper cap on top. It could then have the air inside evacuated via that valve. That article says water is good for temperatures between 20-150 deg C.