[Greenbuilding] Evacuated tube collectors?

[Corwyn]

On Jul 17, 2007, at 21:46, Speireag Alden wrote:
>      The time has come to put in the first solar hot water collectors.

Dear Speireag,

Hope things are going well for you and yours.

Are you set on evacuated tubes?  I am still waffling between them and 
flat panels, would love to hear your reasoning (either way).

You might look at http://www.eos-solar.com/www.eos-solar.com/home.htm I 
spoke to them at our recent energy fair, their product seemed nice (as 
much as can be told from a display model).  I like that their tubes 
replace easily.  During the conversation, they mentioned that there is 
a flexible tubing in the final stages of approval for solar 
applications (just in case running pipe is a concern, though I doubt it 
is for you).

Off the shelf controllers do exist, for  example 
http://www.puristenergy.com/systems.htm

For my system I have been considering just putting a loop from 
collectors, to storage tank, to ground heating (thermal mass), back to 
collectors.  This will ensure a large temperature differential between 
in and out on the collectors, and (I hope) not rob the storage too 
much.  It should also help prevent a storage overheating problem.  This 
means the controller can be simple (perhaps only sun-on, no sun-off 
(i.e. PV panel)).  Turning on and off the ground storage would be by a 
manual valve as I can't figure out a way to incorporate all the 
variables in something automatic.

Your second link isn't very precise about which tubes you are talking 
about.

Thank You Kindly,

Corwyn


-- 
Corwyn
Kermit didn't know the half of it...
http://www.greenfret.com/
corwyn at greenfret.com