[RE-wrenches] Heat dump or Stagnate?

[Troy Harvey]

Apparently this is the "modern" design method used in many european  
systems. It scares me too. But from several sources, this seems to be  
considered one of the most reliable design methods for closed loop  
systems (ie. it works even without electronic controls working, power  
outages, etc).

Standard glycol. The main point seems to be the design of the pipes  
and collectors need to facilitate collector draining from the steam  
pushing the fluid back into the expansion tank, so the collectors  
empty themselves.  Its closed loop, but effectively becomes a  
"pressurized drainback" in over heating conditions.

Here is a couple of links:
	http://www.aee-intec.at/0uploads/dateien48.pdf
	http://www.suterconsulting.com/CISBAT.pdf

I'm hoping to find someone with experience with this kind of system to  
overcome my fears

Troy Harvey
---------------------
Heliocentric
801-453-9434
taharvey at heliocentric.org


On Apr 23, 2009, at 11:04 AM, Dana wrote:

> I have only seen boiled glycol turn to a cola like syrup that had to  
> be
> purged and removed.
>
> What kind of system & glycol is this?
> Where would you expand that much?
>
> Can you provide a link to this paper?
>
> We use heat dumps.
>
>
>
>
> Dana Orzel
>
> Great Solar Works, Inc
> www.solarwork.com
> E - dana at solarwork.com
> V - 970.626.5253
> F - 970.626.4140
> C - 970.209.4076
> "I'd put my money on solar energy. I hope we don't have to wait 'til  
> oil and
> coal run out before we tackle that."
> -Thomas Edison, in conversation with Henry Ford and Harvey  
> Firestone, March
> 1931
>
> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Troy  
> Harvey
> Sent: Thursday, April 23, 2009 10:43 AM
> To: RE-wrenches
> Subject: [RE-wrenches] Solar Combi-systems: Heat dump or Stagnate?
>
> I'm wondering how many of you out there have installed medium sized
> solar hot water systems (6-8 panel) that were designed to stagnate
> during summertime over production as opposed to diverting to a heat
> dump or radiator? The International solar agency has a couple of
> papers that show a properly designed system should be able to stagnate
> in a way that the boiling glycol mix vapors in the panels, purge the
> panels of fluid, turning off the system without degrading the glycol.
>
> That doesn't seem to be a typical way to design systems in the U.S. ,
> we've usually gone to a heat dump. Does anyone have experience with
> this?
>
>
> Troy Harvey
> ---------------------
> Heliocentric
> 801-453-9434
> taharvey at heliocentric.org
>
>
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Options & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive:
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out participant bios:
> www.members.re-wrenches.org
>
>
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Options & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out participant bios:
> www.members.re-wrenches.org
>
>