Replacement Glass for thermal collector

todd
todd Registered Users Posts: 26 ✭✭
Hi All,


I found a broken collector yesterday. The solar collector is 3ft x 6ft and was using 1/8 in low iron tempered glass.

What the recommended replacement with todays products? Can I use a plexiglass equivalent? I'll need high temp and sunlight resistance if I do. But I'd like to avoid paying more for the replacement "window" that what the collector cost me.
A local glass company can provide typical tempered glass, or something called starfire which is a tempered low iron equiv. but at double the cost.


thanks

Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Replacement Glass for thermal collector

    don't let the term plexiglass fool you as it is not glass and is flammable.

    i'm sorry to say there isn't any cheap alternative to this as you must get the high temp low iron glass.
  • todd
    todd Registered Users Posts: 26 ✭✭
    Re: Replacement Glass for thermal collector

    Thanks for the fast reply, I'm not worried about a product being flammable, but the product must allow infrared light to pass, and be suitable for elevated temps (250 degrees F apx) and be sunlight/weather approved. I'm finding many products that may be usable. Just though I'd ask here to see what plastic's would work before I drop the coin for a typical glass product. If the panel wasn't at ground level, I'd use regular glass but in my case safety glass is required
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Replacement Glass for thermal collector

    You can try contacting Solar Roofs and see if they can cut/ship their plastic extruded sheet for your collector. They are supposed to be very DIY friendly (Solar Guppy has used them in the past and has been very happy).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • todd
    todd Registered Users Posts: 26 ✭✭
    Re: Replacement Glass for thermal collector

    Home depo carries a variation of plexiglass, made by Optix their acrylix product appears to offer what I'l looking for 10 year non yellowing statement, outdoor approved, and a temp rating of 300 F. Not sure what the cost is for a 3x6ft section is, will have to inquire... at least it's local and not a special order item...
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Replacement Glass for thermal collector

    When I built from scratch, my domestic hot water panel going on 10 years ago, I didn't know any different, so used what I had. And what I had was a tempered glass patio door with one of it's double glass panes broken out. I built the collector to match the glass size and except for a small water leak which I fixed a few years back, it's worked wonderfully for me for many years now. From mid Spring through late Fall I depend on it for all my domestic hot water and I've been extremely happy with it. The rest of the year my water is heated off the wood stove.
    I have little doubt that the proper glass would yield better results, but given how well mine works, I have to wonder how much better.
    On sunny winter days when the panel is drained of water, it's not uncommon to see collector temps of over 212 F. Surprised the crap out of me. In Summer, after 2 or 3 full sun days, I've seen the water temp in the storage tank at 176 F. Yes, I have to be careful not to scald myself. Not kidding.
    I used to be expecting the glass to break from the temp extremes, but after all this time, I sort of got over that fear.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Replacement Glass for thermal collector
    todd wrote: »
    Home depo carries a variation of plexiglass, made by Optix their acrylix product appears to offer what I'l looking for 10 year non yellowing statement, outdoor approved, and a temp rating of 300 F. Not sure what the cost is for a 3x6ft section is, will have to inquire... at least it's local and not a special order item...

    There is no clear plastic I know of, rated for extended term over 200F, with enough strength to support itself
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
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  • todd
    todd Registered Users Posts: 26 ✭✭
    Re: Replacement Glass for thermal collector
    mike90045 wrote: »
    There is no clear plastic I know of, rated for extended term over 200F, with enough strength to support itself

    You are probably correct, I may have to "glue" a support in the center. However the panels are mostly vertical 70 degrees to be exact and we are only talking about a 3 ft span, so it might not even be an issue. After additional research this product may not be an optimal choice, according to light transmission charts, it appears to block a fair bit of infra-red.

    I have to wonder why do all my projects turn into science research studies