Any Solar HW/PV System Installers Here?

[sleddriver]

I have a two collector HW system I'm in the process of reinstalling on my shingled 5/12, single-story house. My gabled roof deck slopes E & W, with the ridge pointing roughly N & S.

Previously the two panels were installed on a West-sloping deck, perpendicular to the slope using a steel angle-iron bracket at both the bottom and in the middle of the collectors. It looked a bit odd, though this was optimum.

This time, I'm considering placing them flat on the East-sloping roof as the last location is now in deep shade. The copper send/receive water lines are only 1/2" and they'll maybe only be 5" high before connecting to the collectors. Most roof jacks are far too high for this. So I thought of using sections of composite decking as spacers to 'lift' the panels higher up off of the roof surface. Also I need a slight downhill tilt to the fill side in order for them to fully drain during a freeze.

Mine were originally installed rather brute-force approach, leaked at times at the roof penetrations and I want to take advantage of the new rack systems now available if I can.

One issue is solar HW is far less used than PV. Any assistance would be appreciated.

 

[SLATRON]

I have a degree in renewable energy systems engineering technology. Solar potable DHW systems aren't as widespread as PV units but have come a long way quickly. There are many different types of units.
Your setup is using straight water, not a glycol mix because in Texas?
Is there a heat exchanger?
Is this a flat panel collector type?
Do you have access to a Sun Eye or other positioning software to determine best location?
With more info I could try and help some

 

[sleddriver]

Yes, drinking water runs through the collectors. No heat exchanger. Previously I had an 80ga electric HWH plumbed for a solar system. I now have a conventional electric HWH, I'll have to modify to work.

These are metal boxes without any external ribs to attach clips to. However, I can attach steel to the backside using bolts, at both the bottom and about 2/3 of the way up.

No access to Sun Eye. Trees and shade lines from them, including neighbors property due South limits where I can site the collectors. Emphasis on Winter exposure is preferred, even though I am pretty far South in latitude. Problem is I'll have to angle them 90° to the slope of the roof, which can be problematic and a bit awkward. Also have to consider wind-loading. Thus flat-mounting has its appeal, even if it is less efficient.

The reality though is that here, from May to mid-October, until it cools off, I can heat water hot enough to turn it into steam inside the collectors, blowing off the T&P valve. I could heat the entire previous 80ga. tank to > 165°. Unfortunately, I don't use that much hot water during the Summer.

The monopoly electric utility I'm forced to buy power from, raised my rates about 17% last year and went to a multi-tiered rate system. There are no gas lines in my neighborhood, thus I'm forced to heat water with electricity. Once I get the solar system back online however, I just turn off the back-up breaker until around January. Thus electricity use goes from about 4kW to about 40W to run the circulation pump, to heat water.

Thanks for replying.

 

[sleddriver]

Well it appears my post hasn't attracted much attention. Perhaps a few pictures are in order. Here's one way of doing it that elevates the panel above the roof. Note that in my application I'm using solar hot-water panels, not PV panels.

One issue with the black cap shown above is that they don't last very long here in the hot Texas sun. As soon as they crack, split or dry up, these types begin to leak. To replace them you have to undo each connection.

Something similar is used here however by covering the rubber grommets with the panels, they're protected from the direct Sun and UV.

Another use for a similar collar is to snake the wiring through. My water line is 1/2" copper though...it may fit using something like this. However, I also plan on using unions to make connections much easier than before.

Quickmount PV has a system I like. There is still a metal cone underneath the rubber grommet, as opposed to nothing. So this joint could be more easily sealed with something like NP-1 and would be less likely to leak.

This style also has a lot going for it: solid construction, raises the panel up a bit higher, water-tight details:

 

[sleddriver]

Update (and back on topic..):

I've decided to go with QuickMount PV anchors as they're self-flashing, easily adaptable and reasonably priced. The critical joint is raised above the shingles where no roof water drains plus the anchoring structure and flashing are one in the same, designed to prevent leaks. Full compatibility with Uni-Strut (I've been told), which is readily available, means I can easily adapt my older SHW panels to this mounting system.

Fortunately, they also make a self-flashing connector compatible with metal/pvc electrical conduit for use through the roof. Again, the seal is raised above the roof deck away from any roof water. Further this fitting is designed for use with multiple sizes of conduit. Since my send/receive lines are 1/2" copper, I can run them through a short section of pvc conduit and an LB, completely shielding the joint from weather. By anchoring a short section of pvc to the rafters, this will provide a secure mechanical connection, insuring water tightness.

This is the critter I've been searching for. Now I can begin snapping chalk lines, building an inclined plane and rigging a hoist to lift them onto the roof.

 

[andyd]

Wabbout propane? I use that for hot water and stove. Been considering solar of both types. My BIL has 10 units on the south side of his 200+ yr old cape style house.He sells power back to the elec. co. That roof penetration kit looks pretty good. Also, how do these collectors handle hail?

 

[sleddriver]

My small lot is rather tight for a propane tank. My 30 yr. old collectors withstood small hail...emphasis on small as in quarter size, fine. That's the largest hail I've had here since 1982.

 

[sleddriver]

Update:
My SHW project has been progressing well after clearing the hurdle about obtaining the mounts locally. No joy there. After q'ing many installers if they used QMPV's products, I was referred to some large electrical contractors. Not only did they not have the product locally, they didn't even have it within Texas! I'm shocked, SHOCKED it's a true endangered-species-and-no-where-to-be-found in eco-green Austin.

What a weird, strange, trip it's been.....

I wound up ordering them from a solar distributing firm in NJ of all places, for an excellent price. FedEx delivered the box promptly today. After the Surebonder-glue-gun-hunt, I think I'm done with trying to "buy local": It wastes too much time.

Onward....I spent a few hours with a twisted-wire-brush attached to an angle grinder to remove rust, dirt and old paint from the steel angle-irons previously used to attach the panels to the roof. I also had fun breaking several 3/8" bolts and nuts well-rusted together. I actually took the torch to one that refused to yield. Too bad I couldn't get in there with the Sawzall...it would have made quick work of it. Needless to say, these will all be replaced with new hardware.

I borrowed a neighbors MAPP-gas torch to remove all of the copper couplers I sawed through when removing the panels. Made very quick work of it. My torch is just regular bottle gas.

With the mounts now in hand, I can bolt everything together on the ground, take some measurements and transfer these to the roof after snapping some chalk lines indicating where the rafters are.

I've borrowed two aluminum extension ladders to form an inclined plane to match the 5/12 roof pitch and I'll reuse my block-and-tackle rig I used to haul shingles up to the roof. These two collectors aren't near as heavy as three shingle bundles, but much bulkier.

My plan for now is to attach the four roof anchors, then the lower piece of angle iron, hoist the collectors up, then attach them, then add the upper brace and bolt the collectors to it. I'll then mask off the glass with cardboard to prevent them from heating up too much while getting the send/receive water lines in place. I'll be using unions this time to ease installation.

I thought of assembling the collectors together on the ground, sweating the connections, adding the braces, then hoisting the whole thing up. Might be a bit much though. Don't want to damage my new shingles.

I'll post photos as I go. Stay tuned....

 

[sleddriver]

Update 3:

Today I bolted both panels together using the angle iron, assembled the four QMPV feet and bolted them into place. Center-to-center distance across is 48". The vertical distance I marked on a story pole clamped in place to get a more precise measurement. When I laid the whole assembly down with the mounts installed, I measured a distance of 10-3/8" from the center of the water send line to the ground. This will be increased when it's mounted on the 5/12 pitch roof. For now, I just wanted some idea.

This shows the backside with the angle iron & two of the QMPV connectors in place. The wire on the right is for the thermistor which senses the hot water temp after being run through the panels. On the upper left, you can see the stub where the T&P valve, air breaker and hot water outlet is. Note the cut copper line between both panels at top middle. I'll solder these both top & bottom when installed.

Here's a close-up of the upper QMPV mounts, without the aluminum flashing, which will fit between the base and black EPDM gasket. The location they're mounted in are the old holes for the tilt-up base, which won't be used. I may elect to replace the old angle iron with a piece of Uni-Strut and move the mounts outside of the panels. I'd like to bring the panels up one at a time, then bolt them together on the roof.

To more accurately measure the vertical distance, I marked off a story pole. I clamped it in place then made my marks.

Here's a close-up. This will make it easier to accurately place these marks while on the roof.

On the roof, I pried off two sections of the ridge vent to accurately note the location of the roof trusses. I want to be sure both base bolts are accurately placed with no holidays. A couple of measurements showed the trusses are not evenly spaced, though they are close to 48" (fortunately..else it's kind of hard to securly nail down roof decking).

I nailed down a few 18ga. finish nails to properly locate the edges up top, then moved down to the fascia to determine the location of the tails. Now I can snap a chalk line to connect the two.

Should I decide to go outboard, I'll have to attach a couple of 2x's between the trusses so I'll have something to anchor to. The lower brackets will be OK at 4'-on-center, but moving the uppers outside will mean I'll miss one of the trusses. However, this would make installation easier.

The rain forecasted for today/evening didn't materialize, so I look forward to continued work here to get them up and anchored in place. Stay tuned!

 

[sleddriver]

Update 4:

The more I thought of the configuration shown, the more I realized that it "looked" fine on the ground, but what about the process of getting it onto and installed above? Complicated by the fact that I have to solder two copper slips into place up above and unless well marked, the holes in the back of the panels won't line up with same in the bracket. Further, I won't be able to see them either because I'll be laying on my back, reaching in to place them.

With regards to soldering, and bolting it all together, then sliding it up the inclined plane, up the roof on some sort of cardboard or ply to protect the shingles, the whole unit is rather heavy, large and cumbersome for one guy to handle.

New PV installs are done by first siting then installing the roof anchors, then the rails, then each panel is connected to the rail.

So I picked up a 10' section of Uni-Strut and a bunch of hardware. Unfortunately the box store didn't have any of the cone nuts for the shallow-rail US, only the spring-nuts. So I clipped off most of the spring so they'd fit. They also didn't carry 1" bolts, so I trimmed 1-1/2" bolts to fit.

I mounted the US to the panel back, then realized I could use a side-mount instead. This would allow easy adjustment of the mounting locations instead of them being fixed. I'll add photos later to show this.

Using the US also allows me to "outboard" the upper roof mounts where access is easier. It is all coming together...slowly as most custom jobs do dealing with older equipment.

Stay tuned......

 

[sleddriver]

Update 5:

Having never worked with UniStrut or SuperStrut before, I fell into a logistical black-hole regarding the proper "strut-nuts". The box stores carry both A series and B series strut. The difference is the A-series (12 & 14ga) is 1-5/8" tall whereas the B-series is only 13/16" tall.

I chose the B-series because initially I was concerned about getting a socket down inside the channel to tighten a bolt and wanted to be sure it wasn't too deep AND that the OD of the socket would also fit. Since there is little (competent) help there, I grabbed a bag of 1/2" spring nuts assuming they fit both.

Wrong.....

The springs on the regular series nuts (A100) are too long to fit the shorter-height B-series strut. So I improvised, taking a pair of dikes to shorten the spring length. Well I shot myself in the foot here because by cutting them too short, the bar-nut now rotated inside the channel, frustrating my attempts to secure it in place.

A search of SuperStrut's website catalog answered my question: B-series short spring nuts are required for use with B-series strut. Or one can use CM100B-1/2 nylon cone nuts. That's it.

A call back to the box store electrical dept resulted in hearing "Oh yea...we don't carry those. You'll have to call xxxx electric to get those. They have them." No, they don't. Neither did aaa, bbb, ccc, ddd or even eee electric. I called about 8 electric supply houses: No joy. Further...further I repeatedly heard "Yeah we carry them, no prob.." When given the specific part number though, they didn't. Even they didn't understand this.

So I call box-store-management-800-# to ask "Why carry this if you don't carry the correct strut-nuts?" ......I then asked to be elevated up the chain to customer-feedback and was told "No. I can't give you the number, but I will transfer you and you can leave a message." WTH?

More power. More doing. More $%^&$#@!

So I took the time to send an email instead and later received a canned (clueless) response.

Armed with SS catalog print outs, I went over personally to discuss this issue with a store manager. I was polite, but firm. Told him I'd sent an email. Said "They do listen to the customers...us? Not so much.." He kindly refunded all the money I spent on this.

I went to the other box store and they too don't carry B-series nuts but do have plenty of b-series strut for sale. So if you ever need this stuff, just remember to keep your A's and B's separate as they don't play well together.

 

[sleddriver]

Update 6:
I finally have both collectors back on the roof! One's bolted down, the other is resting against the lower rail. Too much Sun and heat already today, so I'll leave it until tomorrow.

I used a torch to remove the send, receive and two copper caps because due to its new location, the left/right sides have become swapped.

I noticed the despite the strut and weight of only one panel, it was sagging more than I planned. I picked up a full-depth piece last night (A-series), then rethought my upper mounts. I could move them inboard, underneath the panels where they'd be protected from weather and into the same roof trusses as the lower mounts. This would prevent me from climbing in the attic and attaching some reinforcements between the trusses. I'd thought of this previously, then discarded it when I was still thinking of hauling both panels joined together up the sled and onto the roof.

With then hauled separately though, this became feasble once again. One of many, many details to figure out during this process and there's more to come.

But those will wait for another day. I'll post some photos later. It's a bit hard to take them while working alone...there's already too many things to keep from sliding off, not to mention keeping my hands clean from the black roofing cement. That stuff can really make a mess on a light colored roof.

 

[sleddriver]

Update 6:

Roof pitch is 5/12, sloping East. Mounted them high up so they'd be exposed to the Sun earlier and I can more easily get around up in this part of the attic. The cardboard protects the tempered glass from accidental tool drops and keeps the temperture in check. The left panel has yet to be placed on top of the lower angle iron and bolted into place.

Originally both upper and lower QM brackets were exposed. Then I decided with a simple hardware repositioning, I could tuck them under the panels for a more streamlined appearance and keep them protected from UV exposure and direct rain.
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Excess strut extending to the right still needs to be trimmed. The difference in glass is due to replacement. Originally both were matte. Unfortunate Northern wind storm blew one over while stored on a covered back porch. It was funneled between two houses and accelerated the velocity, coming right across the porch. Fortunately, the glass is a standard size and readily available tempered.

Fortunately, standard HD right angle brackets from SuperStut were available off-the-shelf and the existing reinforced mounting holes in the collectors lined up.

I've recently learned of a roof penetration fitting/flashing referred to as a "coolie hat". Never heard the term. Didn't come up at all during my search of present methods for making this necessary connection and flashing the joint.

How this works is the "coolie hat" fits over the copper water line and hole. Then an adapter fitting (the coolie hat) is slid down over the pipe, then the pipe is soldered to the copper fitting and to the joint with the coolie hat, ensuring a watertight seal. Using copper prevents any mixed-metal corrosion problems. You can read more about this here. I think I'll use this technique instead of the QM/conduit/copper combination.

I also found an adapter to turn a conventional water heater into one for use with a solar system. It replaces the lower drain valve and allows cold water out and hot water in.

I planned on doing this another way but found the above interesting. Looking forward to moving on with water hook-up as soon as I make a couple of copper coolie hats! Stay tuned....