kevin_in_denver/dawn solar

Andrew Hagen_2

Was the reason for this type of installation to avoid the appearance of solar collectors on the roof? That installation method looks costly.

Would the output go nearly to zero on a breezy cool day? I imagine this would perform similar to an unglazed swimming pool collector? This would perform a LOT better if the roof was covered with glass and the copper had a selective coating.

I could see this installation performing well under certain circumstances, but I question the economics. I see a lot of labor on that roof. Every dollar spent on labor could have been spent on additional high efficiency solar collectors and storage.

The workmanship looks excellent.

[Deleted User]

thanks to kevin_in_denver/dawn solar

http://www.dawnsolar.com/gallery.html
"Both the Florida Solar Energy Center (FSEC) and the Solar Rating and Certification Corporation (SRCC) have certified Dawn Solar Systems."
"The company has projects complete or in development in over 30 states, Canada, the Caribbean and the European Union."

click on the picks to the right to see the close-ups of the pex under metal roof usage

[Deleted User]

those questions

are answered on the site link and the alternate links that they provide; such as the metal roofing institute link which details the types of finishing surfaces and their properties. and, dawn solar does say that their system doesn't work for baseboard heating, but works well for lower temp radiant floor. and yes, while aesthetics plays a big part of the concept, their cost comparisons say that it's cost effective. but of course, they would say that

Andrew Hagen_2

Payback

I don't see any hard numbers or economic analyses on the site.

Rough numbers, I would guess that each man-day of labor could almost buy another flat plate collector. Based on that, I bet a 500sf roof installation could buy 6 to 8 4x8 flat plate collectors that would almost certainly vastly outperform 500sf of unglazed collector in a heating climate. The pex also takes a heavy toll on the heat transfer. If ice forms on the roof, this system would have to melt the entire south side of the roof before heat collection could begin.

I am speaking purely from an investment standpoint. It appears that cost-effectiveness and performance may not be primary goals for these systems.