Drainback on flat roof
I'm doing a drain back system on a flat roof. There will be 8 panels installed. I would like to pitch 4 panels to the left and 4 panels to the right a 1/4" per foot from the roof termination. The termination of the roof will be the supply and return runs. I would also like the front of the panels 6" off of the roof for the snow to blow under. Ive been racking my brain tyring to figure out how to do this out. Does anyone have any suggestion
Thanks
Rich
maybe
consider buying some 2" square tubing, shop for galvanized plated. Mount that to the roof at a 1/4" pitch, then mount the collector mounting feet to the tube with tek screws. The rack becomes the pitch mechanism, then use a second tube to mount the back legs to. This will limit the amount of roof penetrations.
With a little more design you could do a ballasted system and eliminate any roof penetrations except the piping. Maybe the piping could go off the roof and enter the side of the building.
There are racking manufacturers that offer ballasted and bolt down packages. Schletter, ZillaRac, Unistrut are a few brands.
hr
I'm not a fan of drainback
I'm not generally a fan of drainback systems cause I think they are a pain in the ass, ugly and failure prone.
But in this case we were unable to convince the specifying engineers to change their plans and so we did do drainback...on a flat roof no less. I think this sounds similar to what you are planning:
http://www.revisionenergy.com/solar-projects/schools-nonprofits/durham-elementary/
If you are interested, I can probably find some install detail photos or plans that I could send your way.
~Fortunat
www.revisionenergy.com
