panels on a bowed roof [RE-wrenches]

[Jeff Clearwater]

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Hi Kirk,

Yes, that's one way that might work nice for the PV.

Perhaps instead of trying to shim each rail row to square off to the 
panel with top clips , you could use a perimeter mounting system like 
Sunframe or Comprail (Sunearth) or the new ITT rail 
(www.thompsontec.com) and then each common rail would be only a few 
degrees off of flat to each of panel row - it might work depending on 
the degree of change of your bow.  The ITT has the biggest "shelf", 
the comprail is not much smaller - those might work better than the 
narrow shelf of the Sunframe.

For the DHW, Could you perhaps used evacuated tube collectors?  - 
then your "facet" size would be your header size.  Apricus tubes are 
my favorite.  Drainback with Apricus makes a very simple sweet high 
reliability hot water system and looks a whole lot nicer than 4 x 8 
boxes.

Just a thought - seems a shame to put a big flat collector on a convex roof!

Best,

Jeff C.

>
>Jeff,
>
>Its not easy to follow the arc when 4 x 8 DHW collectors have to be
>mounted in side-by-side in portrait mode per customer request.
>
>I could mount multiple rows of PV panels in landscape mode, on Unirac
>rails. The rail feet would have to be shimmed to allow the panel to lay
>flat on the rail, and Unirac sells shims. Each row of panels would
>"follow the arc" on its respective slope.
>
>Kirk Herander
>Vermont Solar Engineering
>802.863.1202
>fax 802.863-7908
>NABCEP(tm) Certified Solar PV Installer
>Xantrex Certified Dealer Charter Member
>NYSERDA-eligible installer
>VT Solar and Wind Partner
>
>
>-----Original Message-----
>From: Jeff Clearwater [mailto:clrwater at earthlink.net]
>Sent: Wednesday, March 01, 2006 7:47 PM
>To: RE-wrenches at topica.com
>Subject: RE: panels on a bowed roof [RE-wrenches]
>
>Hi Kirk,
>
>Again, why not follow the arc?  It would look so much better, be so
>much easier to rack, have less uplift and support problems???  Your
>facet lengths would be your panel width.  You simply use standoffs to
>each panel.  Clean follows the architecture and elegant.
>
>Best,
>
>Jeff C.
>
>
>>
>>William,
>>Thanks for your good advice.
>>To be clear, this is not to compensate for an old sagging or warped
>>roof.
>>>From a side view, the roof is not a straight slope but rather a long,
>>sweeping arc, the slope of which varies depending on the height of the
>>roof you're at. Call it a bell curve, sort of. It has a name
>>architecturally, but I forget it. The challenge is to create an
>>evenly-sloped rack to mount panels which is "tangent" to the arc and at
>>proper tilt angle at point of mounting.
>>After looking through some catalogs, I found that unistrut makes a 6"
>>strut welded to a 2 hole mounting plate. They also make a hinge. So the
>>tangent can be made by bolting one end of the hinge to the top of the
>6"
>>unistrut mount, then bolt unistrut rail to the top end of the hinge (2
>>feet per rail). The rail is the tangent line running up/down the roof.
>>Several of these rail assemblies across the roof form the base to bolt
>>on horizontal unistrut rails and problem solved. I hope.
>>
>>Kirk Herander
>>Vermont Solar Engineering
>>802.863.1202
>>fax 802.863-7908
>>NABCEP(tm) Certified Solar PV Installer
>>Xantrex Certified Dealer Charter Member
>>NYSERDA-eligible installer
>>VT Solar and Wind Partner
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-- 
~~~~~~~~~~~~~
Jeff Clearwater
Village Power Design Associates
Sustainable Energy & Water Solutions for Home & Village
http://www.villagepower.com
gosolar at villagepower.com
NABCEP (tm) Certified Solar PV Installer

530-470-9166
877-SOLARVillage
877-765-2784
72 Baker Rd.
Shutesbury, MA 01072
425 Nimrod St.
Nevada City, CA 95959
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`~

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