Hi all
Feeling pretty stymied here. It appears there are only 2 sellers in US for evacuated passive SHW systems, Dudadiesel and Solarbank. Seems like a few different makers of tubes like Apricus, thermomax etc. but all going in to active systems with pumps. And seen many problems listed here with those makers anyway.
Duda uses salt water in the heat rod and rated to 14F. Solarbank is like 600 bucks more, OUCH! but uses copper powder/water mix and rated to neg 35F. Do need something would go pretty cold but 14F Duda is okay. Thing is, quality unknown in other ways with either brand. Absolutely minimal risk of long term problems is the goal here like coatings decaying or slow vacuum leaks.
Apparently even in best system air does permeate glass with expansion contraction of heat/cooling but don't know what that rate is if anyone could comment. A 10% vacuum loss or coating decay in in 25 years say like a pv panel would be okay.
The angle on this question, my main concern, is poor workmanship or design.
Anybody else? what should I do? Whole industry seems untogether imo. Really have to work to get info and can't trust that. Undisclosed China makers etc. I know, move to China and buy from the local hardware store who's owner buys eggs from you.
Solarbank doesn't seem to have certification. Manual is a lot better though, which shows diligence.
Second choice is get a flatplate collector and drain in winter plus put up with less efficiency. At least wouldn't have vacuum or coating problems in 5-10 years. But they are scarce also so any recommendations who?
ET sure is tempting if just look at specs unless one has real sunny winters.
What happened? Seems like more choices few years ago. Doesn't mean quality was there of course
This post keeps screwing up, repeating sentences and can't edit.
Thanks
Feeling pretty stymied here. It appears there are only 2 sellers in US for evacuated passive SHW systems, Dudadiesel and Solarbank. Seems like a few different makers of tubes like Apricus, thermomax etc. but all going in to active systems with pumps. And seen many problems listed here with those makers anyway.
Duda uses salt water in the heat rod and rated to 14F. Solarbank is like 600 bucks more, OUCH! but uses copper powder/water mix and rated to neg 35F. Do need something would go pretty cold but 14F Duda is okay. Thing is, quality unknown in other ways with either brand. Absolutely minimal risk of long term problems is the goal here like coatings decaying or slow vacuum leaks.
Apparently even in best system air does permeate glass with expansion contraction of heat/cooling but don't know what that rate is if anyone could comment. A 10% vacuum loss or coating decay in in 25 years say like a pv panel would be okay.
The angle on this question, my main concern, is poor workmanship or design.
Anybody else? what should I do? Whole industry seems untogether imo. Really have to work to get info and can't trust that. Undisclosed China makers etc. I know, move to China and buy from the local hardware store who's owner buys eggs from you.
Solarbank doesn't seem to have certification. Manual is a lot better though, which shows diligence.
Second choice is get a flatplate collector and drain in winter plus put up with less efficiency. At least wouldn't have vacuum or coating problems in 5-10 years. But they are scarce also so any recommendations who?
ET sure is tempting if just look at specs unless one has real sunny winters.
What happened? Seems like more choices few years ago. Doesn't mean quality was there of course
This post keeps screwing up, repeating sentences and can't edit.
Thanks
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