We just broke ground on our new home it has 1900sqft on the main with unfinished basement.  I will have pex in the basement slab for future radiant heat.  The construction budget doesn't have room for a SHW system, however I would like to pre-plumb so to speak for adding a system in the future.  I am wondering if rack systems for PV roof arrays are universal for SHW systems?  If I can install some posts to the rafters before the shingles go on?  Any thought or Ideas would be appreciated.


Thanks,

Darren

Given than solar thermal panels weigh several times that of PV, I'm doubtful that it would be an appropriate racking system.

As Dana stated thermal systems definately weigh more than pv systems. Post supports will accommodate unistrut or similar materials. The key is rafter loading, spacing of supports and the quantity needed. Do not forget the plumbing flashings along with the sensor wiring. A typical flat panel can weigh up to 160 pounds. Snow loading and wind upload need to be considered as will as any seismic forces wich may exist in your area.

Zilla makes racking for PV and Thermal with flashings. You may find something there but it is not difficult to do later. You would do well to put yr feed and return lines to the roof (attic) ahead of time (and sensor wire). That saves hacking thru a closet later. Use larger than you think pex in the slab heat. It's all about flow and keeping the panels cool in solar.

What type of roof are you putting on?

Another possibility you may want to consider is to install just the panel and plumbing (or just the panel, with chases for running line) now, and install the solar tank, etc. later on. If you use a flat panel collector (as opposed to evacuated tube type, assuming you are in a location where this makes sense), the panels themselves are about half the price of the system (not including install labour), and you can end up with a roof-integrated system now. ie, get the roofer to flash around the panel, and have the panel rest on the rafters. This part of the installation is a significant part of the cost labour-wise anyways.