sierra--- solahart market an evacuated tube system as do hills ,they dont rely on reflectors its double insulated glass tubing that entraps heat bit like leaving a coke bottle out in the sun with lid on water does not run through the tubing---
look it up on the net----evacuated tube solar hot water,its not a solarhart system with a roof mounted tank and water recirculted through tubing covered in glass with a reflective back panel--noooo! completely different with no major problems
