Drainback vs. Closed Loop Circulators [RE-wrenches]

[solarpro at aol.com]

Hello SHWrenches:

Drainback systems for space heating is very good advice.  Even if you have a 
"dump" load, pool/spa/geothermal, a closed or 'open' loop system will overheat 
if (WHEN) something goes south.

I've never come to closure on one issue re drainbacks - is it better to use 
distilled/de-ionized water or tap water?  I understand that "tap" water covers 
a lot of territory, but the only drain-backs I have had serious problems with 
were systems using distilled water - actual copper tubing failure unrelated to 
erosion corrosion.  I've seen waterways turn to copper foil.  I suppose it 
could have been due to high heat in a moist environment but somebody a long time 
ago told me that distilled water is "hungry" and will eat away metals.  It 
does seem that the best way to resolve this issue is to use a buffered glycol, 
but pump head and heat absorption do suffer. 

Anybody copy my experience with distilled or de-ionized water?

Patrick A. Redgate
AMECO
Long Beach, CA
(562) 595-9570
www.amecosolar.com 


In a message dated 6/7/2006 5:14:18 PM Pacific Standard Time, 
conradg at cape.com writes:

Hi Ken,
No confusion between Draindown and Drainback here.
And I don't mean to imply that our experience with drainbacks is universal. 
Just reporting in from the feild without a lot of detail.
My opinion on the issue is that you go to a drainback for a space heating 
system but stick to a closed loop for SDHW.
your glycolhead,
Conrad Geyser
Cotuit Solar


- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------