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Available panels constantly changing?

67King

New Member
Joined
Apr 23, 2023
Messages
64
Location
Friendsville, TN
New construction, has taken much longer than we expected for various reasons. But after we move in, I'll be installing a ground mount solar carport/awning/pergola type thing. Have to wait until we move in because the area I'll be mounting it is supposed to be held in reserve for the septic system (which is weird, because it isn't going there - but you know, regulations and all). At any rate, I've been "designing" a system based on this one spot for a while, but it seems every time I go look and tweak, the panels I had planned on using are not around anymore.

So what is going on, here? Are companies like Canadian Solar, Blue Sun, etc. just changing their panels so fast that they have new systems every few months? Am I just spinning my wheels wanting to make sure that I've got an optimized setup, meaning I should just stop worrying about it until I'm ready to buy?
 
Basically yes.

Go ahead with the rough design, but don't worry about the final design of your solar thing until you're ready to buy the panels.
 
Forget the individual panels, plan to a size. I first started using panels 1M wide by 1.7M tall which can be 200W to 300W, next array will be 1.134 x 1.722 panels which seem to start at 410 and go to 450W. I will pick the cheapest per watt on the day I buy.
 
Basically yes.

Go ahead with the rough design, but don't worry about the final design of your solar thing until you're ready to buy the panels.

Rough design is 48' long, including overhang, and posts 16' apart, EXcluding overhang. Length is dictated by the width of the house, and post spacing is twice the width of the trailer, to give me the ability to maneuver it, as the structure will double as a covered area for my truck and trailer (3/4 ton and 28' enclosed car trailer).

So the 400 Watt panels would be about 13x4, or the 550 Watt ones would be a 13X3. That puts the long at 48.3', so I can live with a few inches longer than that side of the house. Each array would be a bit over 22', so I'd have an aesthetically decent overhang with the roof pitch (pitch is going to be TBD once everything is done and the area is graded, as the lot is hilly - two pitches on the house are 7/12 and 3.5/12 - 7/12 is optimal for my location).
 
For people in your area ( and mine ) air conditioning is one of the largest loads that matters.

Don't worry all that much about optimum angle at the optimum time of day, try to have panels collecting sunlight from early morning to very late in the afternoon.

At my work shop, I have panels mounted
- Vertically to collect sunlight first thing in the morning ( ~ 25% )
- Others vertical facing the late afternoon / setting sun. ( ~ 50%)
~ 25% facing mid day

The general direction is that the cost of power in that late afternoon time period has the most value.
 
For people in your area ( and mine ) air conditioning is one of the largest loads that matters.

Don't worry all that much about optimum angle at the optimum time of day, try to have panels collecting sunlight from early morning to very late in the afternoon.

At my work shop, I have panels mounted
- Vertically to collect sunlight first thing in the morning ( ~ 25% )
- Others vertical facing the late afternoon / setting sun. ( ~ 50%)
~ 25% facing mid day

The general direction is that the cost of power in that late afternoon time period has the most value.

Yes, the least used heat pump will be 19 SEER on the AC side, the other two are 20 and 21.5. Spray foam insulation trhroughout, 2x12's on the ceiling, so 11.5" of foam there, and 2X6's on the walls, so 5.5" there.

Will be building a second array on our dock once I get that built. Will be about 3/4 the size of the main one, but will have panels at different orientations.
 
A word of caution, I really don't know how true this is but I read last week that home insurance company's are refusing to insure homes with sprayed in insulation.
Greg
 
A word of caution, I really don't know how true this is but I read last week that home insurance company's are refusing to insure homes with sprayed in insulation.
Greg
And how do they propose to determine what insulation a house has, demand people cut their walls open? "Oh sorry by the way, that hole isn't covered by your policy!"
 
Manufacturers that make their own panels tend to change their products less often. Q Cells 480's been the same models for years now, even from three different factories in China, Korea, and USA they're all the same spec.
 
No I don't but I saw it on the Microsoft Edge website about 2 or 3 weeks ago..
I did read part of the piece and they said it was because of the elevated repair cost with the foam verses the standard fiberglass.
They all so said in the piece that if the insurance company's find out you have the blown in foam they will cancel your policy.
That is why I said I wasn't sure because I don't trust these national new's organization's.
Then tend to use a lot of click bait.
Greg
 
No I don't but I saw it on the Microsoft Edge website about 2 or 3 weeks ago..
I did read part of the piece and they said it was because of the elevated repair cost with the foam verses the standard fiberglass.
They all so said in the piece that if the insurance company's find out you have the blown in foam they will cancel your policy.
That is why I said I wasn't sure because I don't trust these national new's organization's.
Then tend to use a lot of click bait.
Greg
Microsoft is not a news organization. And if you mean you clicked on one of those MSN links, they are an aggregator that steals bundles work from other sites so they can track your internet browsing and serve up ads to you.
 
A word of caution, I really don't know how true this is but I read last week that home insurance company's are refusing to insure homes with sprayed in insulation.
Greg

There's been an article from some less savory British publication about this, the assertion is that it traps moisture and causes the wood to rot. I've seen it several times over the past several months, and I have put it into the same bin as the reports that the mining required to make EV's is worse for the environment than if every Chinese person were driving a Canyonero, etc. There seems to have been one case where an existing dwelling that was not so well sealed up had spray foam insulation applied, and suffered problems that would have happened regardless, but was blamed on the foam because it was newer than the straw that was used in teh 1600's.

Anyway, thanks for teh heads up, but since we are building with foam from the get-go, we will not be flowing air through the rafters, it will be completely sealed up, so there wont' be any source for moisture to get in there and cause damage.

Ironically, I've spent teh past 5 days rebuilding a 12 year old deck that had several structural failures due to trapped moisture - outdoor deck with pressure treated lumber.
 
Its not just insurance related but UK mortgage companies will not lend on a house with sprayed on insulation. The insurance is the lesser problem, unless they ask when the policy is set up then the insurance will find it difficult not to pay out a claim. I have never been asked what type of insulation is on the house when renewing house insurance to date. Getting a mortgage is the bigger issue as the required mortgage survey will point out the insulation type and then the house becomes a cash sale only with a lower value.
 
Its not just insurance related but UK mortgage companies will not lend on a house with sprayed on insulation. The insurance is the lesser problem, unless they ask when the policy is set up then the insurance will find it difficult not to pay out a claim. I have never been asked what type of insulation is on the house when renewing house insurance to date. Getting a mortgage is the bigger issue as the required mortgage survey will point out the insulation type and then the house becomes a cash sale only with a lower value.

Appreciate the caveat. Not a problem in my specific case. A few factors - one, much warmer climate (southern US) so the cycling into colder temperatures that would allow condensation to build up isn't going on as often. Second, when they do spray foam here, they fully seal the space, which again gets to the part about temperature cycling and condensation.......fresh humid air will not be able to get to the area where water would condense. Basically, the system is designed to use foam, whereas more conventional fiberglass or blown in insulation would require ventilation. Foam is NOT appropriate for use in ventilated systems, but when I read the article however many months ago, that was what was being done. Third, the foam that has already been applied in a couple of places in the house was done properly, where there are no open gaps that the foam didn't reach (unlike the pictures I saw where a guy was able to reach up and feel the wood under the shingles). Fourth, as this is new construction, we are required to have inspections done in process, meaning if the foam were to be installed improperly, there would be a third party that (at least in theory) would be able to point out this to prevent things lie unfilled gaps. Fifth, I've already got a construction loan for the build.

Basically, from what I've read, the foam in that story was not applied correctly. And like anything, incorrect application can lead to issues.

That said, for anyone in colder climates and/or considering this with existing dwellings, your caveat is appreciated. I'd say that for those situations, the closed cell foam may actually be what is best. It doesn't expand like the open cell, and goes on like a thin layer. About twice the R-value, so is used in different situations than the open cell (often in conjunction with fiberglass). So it completely seals off the areas from any humid air that may be in the attic from a ventilated system. Think about it like a thick paint. It may be possible to use it with the open cell, which expands, but the closed would go against the structure, then the open on top of it. That may be a good solution that would prevent the ability of a system to trap moisture and cause rot.
 
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Sounds like I am ahead of you in the home build, my foam contractor suggested 2 in of closed cell up against the roof deck for maximum insulation and to quite literally glue everything together followed by 4 inches + of open cell for its general insulating properties and sound deadening. Obviously the price difference between the two adds to your calculations.
Added bonus is now none of the HVAC ductwork needs to be insulated and is running in a semiconditioned space, but I used the regular slightly insulated ductwork anyway.
 
Sounds like I am ahead of you in the home build, my foam contractor suggested 2 in of closed cell up against the roof deck for maximum insulation and to quite literally glue everything together followed by 4 inches + of open cell for its general insulating properties and sound deadening. Obviously the price difference between the two adds to your calculations.
Added bonus is now none of the HVAC ductwork needs to be insulated and is running in a semiconditioned space, but I used the regular slightly insulated ductwork anyway.

We should be pretty close. The closed is about twice as effective as open, but I've got more space. But yes, the closed cell stuff, from what I understand, does completely seal off everything. We have some tricky decks over living areas that have the closed cell and then open cell on top of it. So far, those were done early, but our electrical, plumbing, and HVAC are just being wrapped up, so we still have to have the inspections for those before the foam goes in. One other thing I should have mentioned previously, proper installation of foam will require trimming. In other words, when they sprayed ours, it expanded pasted the joist surfaces, and after it cured, they had to cut it down flush so OSB (or drywall in upcoming applications) could be applied. There is a fair amount of waste, unfortunately, but that is what proper installation looks like.....may not be necessary, though, if going over closed cell in ceiling or wall type environments, since the closed cell seals off everything pretty much perfectly.

For the roof and walls, I had actually asked abotu closed, then open on top of it, but the builder indicated that I'd see diminishing returns relative to investment. I opted to skip a metal roof with a radiant barrier for similar reasons ($30K cost difference!). We'll have cathedral or vaulted ceilings in most of the rooms in our house, so our HVAC ductwork can only go in certain areas, but most of it will be closed off entirely, so ours will be insulated.
 
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My walls are ICF so no spray foam in those apart from where the wire and plumbing chases were made.
All the spray foam is up on the roof deck so no trimming for me 😁
 

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