Running the Feed and Return Lines
from the Roof to Ground Level
Discussed here is the standard, most straightforward
way of running the PVC pipe from the feed and return
lines to the equipment pad. Some installations require
a more creative approach due to unique roof designs
or equipment pad locations. Whenever possible, how-
ever, the return line should have the shortest run and all
pipes should run slightly “downhill” to allow for auto-
matic drain-down of the plumbing and solar array. As
discussed earlier, if this is not possible, manual drain
valves should be installed as needed.
If your equipment pad is against your house, you may
want to complete the necessary plumbing at the equip-
ment pad before completing this portion of the instal-
lation. This allows you to know exactly where the pipes
should come down from the roof. If you will be trenching
from the equipment pad to the installation location, this
is not necessary.
1. Cement the appropriate size PVC 90 degree elbow
to the return line stub facing down toward the bottom
header. Repeat the process for the feed line header
stub and face the elbow down away from the array (see
Fig. 14, page 17)
Note: Whenever cementing, lay a rag on the
roof or rack under the joint to avoid dripping
cement on the mounting surface. Also, it is
a good idea to tape the cans of PVC cleaner
and PVC cement together. They are less
likely to tip over and spill this way.
2. Determine where the feed and return pipes will go
over the edge of the roof. If possible, this should be per-
pendicular to the exact points where they will fasten into
the existing system or into pipes coming from another
location. (See Fig. 15, pg. 18)
3. Measure the distance from the return elbow down to
the spot that you want to go, across the roof, to the point
established above. Be sure to include the depth of the
socket in the elbow in your measurement. Cut a piece of
PVC pipe to this length. Repeat this process for the feed
line.
4. If you are not experienced at cutting and fitting pipe,
it is a good idea to assemble all pipe and fittings before
cementing them just in case you make an error. Clean
the burrs off these cut pipe lengths and insert them into
the elbows.
5. Measure across the roof from these pipes to the
points established in step 3. Cut and de-burr pipes to
these lengths and assemble corner with 90 degree
elbows.
6. Continue this process around the edge of the roof
and down to the existing plumbing, using a level to keep
the pipes looking plumb and keeping pipes as short,
straight and tight to the building as possible.
7. Once you are satisfied with the plumbing arrange-
ment, go back and cement the joints together using the
good plumbing techniques explained in the “Getting
Started” section.
8. Secure long pipe runs with pipe clamps or “G” pipe
clamps one size larger than the pipe diameter using
(116) #14 S.S. hex head screws and polyurethane caulk.
Secure vertical pipe runs on the side of buildings with
pipe clamps the same size as the pipe diameter using
screws and anchors as needed.
Note: All four corners of each row of collec-
tors should be surely fastened to the roof.
The corners should already be secured
with the “G” pipe clamps or pipe straps on
the plumbing lines connected to the feed
and return lines. The top corner opposite
the return corner should already be se-
cured by the collector mounting hardware.
Note: Be sure to support all of the weight
of the plumbing with “G” pipe clamps or
pipe straps. The mounting hardware is
not designed to support the weight of the
plumbing in addition to the weight of the
collectors.
16
Summary of Contents for HC10.5
Page 19: ...17 End Cap u t Return Line End Cap p Feed Line q Rib p Fig 14 ...
Page 27: ...25 Notes ...
Page 28: ...26 Notes ...