Non-wood Solar collector ground mount

[tradewinds]

Looking for recommendations on non-wood material ground mount for solar collectors.

I have a kit of Qty (10) 12'x4' and contemplating either a top 5/bottom 5 or straight 10 configuration.

I've seen housing metal wall struts used in a video by the retailer.

How have you built yours with non-wood and is it holding up to the elements?

 

[Ahultin]

No answers yet so I'll throw this out there again. I did a search on here and found only examples of wood racks.
While I was researching I only found three examples
1. The solar pool supply version out of fence poles and steel stud
2. The ecosolar design with unistrut (what I used) Strut-channel Rack
3. Diable solar (pictures only) that looks to be a hybrid of the above 2 Solar Pool Heating Systems | Diablo Solar Services

 

[tradewinds]

No answers yet so I'll throw this out there again. I did a search on here and found only examples of wood racks.
While I was researching I only found three examples
1. The solar pool supply version out of fence poles and steel stud
2. The ecosolar design with unistrut (what I used) Strut-channel Rack
3. Diable solar (pictures only) that looks to be a hybrid of the above 2 Solar Pool Heating Systems | Diablo Solar Services

Thanks...I forgot yours was with unistrut, thought it was all steel pipes. Any reason you didn't do the steel studs? I haven't priced any materials as yet either.

 

[Ahultin]

Any reason you didn't do the steel studs

Overthinking lol. The steel studs seemed flimsy and I did not care for the method of attaching the steel studs to the fence posts. The unistrut also uses bolts and nuts vs self tapping screws. Given the weight of the panels and the addition of the powder coated metal roof sheeting as underlayment, I expect the rack to outlast me

 

[tradewinds]

Overthinking lol. The steel studs seemed flimsy and I did not care for the method of attaching the steel studs to the fence posts. The unistrut also uses bolts and nuts vs self tapping screws. Given the weight of the panels and the addition of the powder coated metal roof sheeting as underlayment, I expect the rack to outlast me

What did you use for the footers, steel pipes or fence posts?

 

[Ahultin]

1.25" schedule 40 galvanized pipe

 

[tradewinds]

1.5" schedule 40 galvanized pipe

Thanks. What did the over dimensions of your frame and your substrate? And distance between your collectors?

Also, I notice your return from the collectors is atypical in the center, any particular reason on that design?

 

[Ahultin]

What did the over dimensions of your frame

Left the house for a bike ride so I'll have to measure when I get back home. As I recall, overall was ~44x13

Also, I notice your return from the collectors is atypical in the center, any particular reason on that design?

For optimal flow, the manual gives a limit of 8 4x12.5 panels in a single row

I used the split feed model from the manual

 

[tradewinds]

OK, I see. I didn't take delivery as yet to view a manual. Good that all that is included.

 

[Ahultin]

https://cdn.shopify.com/s/files/1/0256/6910/7809/files/SwimJoy_Installation_Manual_V2021.1C.pdf?v=1640722750

 

[tradewinds]

@Ahultin - trying to get materials quantity ballpark. What were your measurement for the back posts and front posts and unistruts?

 

[Ahultin]

@Ahultin - trying to get materials quantity ballpark. What were your measurement for the back posts and front posts and unistruts?

My goal was to use 1 10' post for front and rear , roughly 6' front 4' rear with a ~30" depth
The deeper uni strut runs front to back @~13' length
The shallow uni strut runs side to side the full ~44'

 

[tradewinds]

My goal was to use 1 10' post for front and rear , roughly 6' front 4' rear with a ~30" depth
The deeper uni strut runs front to back @~13' length
The shallow uni strut runs side to side the full ~44'

You mean 6' in rear?

 

[Ahultin]

You mean 6' in rear?

Lol, yup

 

[tradewinds]

Lol, yup

So, without doing my trigonometry, this gave 13-degrees tilt?

 

[Ahultin]

So, without doing my trigonometry, this gave 13-degrees tilt?

Keep in mind that my rack is installed on a multi-planed slope so all of the posts are actually of varying heights to maintain level across. The west end of the array is only ~2ft off of the ground while the east end is almost 6ft.

The recommendation from where I borrowered the design was the following:

The sub-rack is built from 1-1/4" galvanized plumbing pipe or "rigid" conduit (do not use EMT conduit) that you can find locally. You can use 1-1/2" too for a stronger rack. It consist of short vertical posts in the front spaced every 8-10' (max.) to span the required width of the rack. There are longer vertical posts in the back also at 8-10' apart and roughly 9' to 10' behind the front posts for 12' panels the height of which will determine the pitch of the rack. It is usually easiest to use one 10' length of pipe to make both the front and back post (2-1/2' to 3' for the front and the remaining 7' to 7-1/2' for the back).
All posts should be cemented into the ground at least 18-24". The posts will then be 12-18" out of the ground in front and 5' to 5-1/2' in back. This give roughly a 25o pitch which works well with summer heating. Pitch should be somewhere around local latitude less 15o for summer use and latitude plus 15o for winter use (i.e. Hawaii). Minimum recommended pitch is 6 degrees for drainage purposes.

 

[tradewinds]

@Ahultin - What type of channel struts did you end up using. Depending on type and place of order, prices are shifting quite differently. I assume you did 12-gauge, 10' lengths? About what was to cost of each piece?

 

[Ahultin]

The front to rear supports where the 12 ga full depth superstrut pieces from home depot, the side to side where the 14 ga half depth superstrut also from home depot. Make sure you buy them in quantities of 10 or more (knowing you can return what you don't use) as they get the quantity discount.
Fyj, For the nuts I found the nylon ones to be way more user friendly than the spring ones and they worked on the full and half channels

 

[tradewinds]

@Ahultin do you have some photos and instructions how you attached the unistruts to the pipes? I assume the goal is to get a flat "picture frame" to put the roof panels onto?

 

[Ahultin]

@Ahultin do you have some photos and instructions how you attached the unistruts to the pipes?

It appears i did not get any good pictures of that however , as I used the eco solar systems instructions, they have some good photos. It essentially just is a properly sized ubolt, washer, plate and nuts.

I assume the goal is to get a flat "picture frame" to put the roof panels onto?

That is correct