[RE-wrenches] My .02 onEvacuated Tube-based SDHW

Wed Mar 25 08:35:55 PDT 2009

Peter – 

I may have been who you spoke with. 

Since 1995 I have installed 3 kinds of flat plate SHW collectors and
THERMOMAX / OVENTROPE,  SUNDA and APRICUS evacuated tube collectors. 

Long story shortened on the evacuated tube collectors. 

I have replace 290 of 300 evacuated tubes by manufactured by Thermomax after
3-4 years. I had replacements in the first year, I do not remember the #
replaced. Been there and not going back.

>From the experiences with evacuated tubes the major short coming is the
intersection of glass to rubber collar to heat pipe. 

I see the single wall glass evacuated tube collectors as a recipe for
eventual failure. 3 materials 3 different thermal expansion and contraction
co-efficient. Add “wine glassing” where the bottom of the single wall glass
vacuum tube falls off [looks like a wine glass without a base] and I would
not install one if you gave it to me

The first time I saw the APRICUS evacuated tube build I was sold. The vacuum
is between a tub in a tube, it is glass on glass. The heat pipe fits inside
the inner tube in a heat collector piece of galv.  sheet metal, and no
rubber collar  that is required to maintain a vacuum seal. I love it.

The glass vacuum tubes are heavier and less prone to an accidental bang and
break.

If a glass tube gets broken you can replace the glass vacuum tube separate
from a heat pipe, and if the heat pipe fails you can replace jut the heat
pie and reuse the tube.. I like components and this is the great advantage
with APRICUS over the other designs.

15 year warranty on the manifold and 10 year on the glass vacuum tube and
heat pipe. 

The whole tube is black and absorbs heat 360° so it even picks up heat on
the back off of a roof or reflected surface behind.

This works for me. I am now an APRICUS dealer for evacuated tubes and use
several flat plate manufacturers.

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

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Peter
Parrish
Sent: Wednesday, March 25, 2009 7:41 AM
To: 'RE-wrenches'
Subject: [RE-wrenches] Evacuated Tube-based SDHW

Back at the San Diego Solar 2008 show, I made a point to look at a number of
evacuated tube systems for SDHW. I got one very strong recommendation from a
Colorado-based installer I bumped into, and
I promptly put the information
into “write-only” memory. So here I am six months later no better off than I
was before I went to the show. 

Has there been a recent thread on evacuated tube SDHW systems? If so, how do
I access the archives? If not could we start a thread?

My principal reason for looking into this technology is for space-limited
applications. Right now we are looking at trying to find space on a crowded
roof for about 100-120 sq-ft of conventional flat plate collectors (e.g.
SunEarth Empire 4’x8’ or 4’x10’), and skylights, parapet walls and a PV
array are getting in the way. Climate is southern California coastal.

Any help would be appreciated.

- Peter

Peter T. Parrish, Ph.D., President
California Solar Engineering, Inc.
820 Cynthia Ave., Los Angeles, CA 90065
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parrish at calsolareng.com 

  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Peter
Parrish
Sent: Wednesday, March 25, 2009 6:05 AM
To: 'RE-wrenches'
Subject: Re: [RE-wrenches] MPPT greater than 150V

Yes, as far as I know.

Apollo is supposed to have one in beta evaluation but we haven’t been able
to obtain satisfactory information from them how product evaluation is
taking place and when the unit will be available as a product. We had an
application for which we wanted to use this new product and gave up on them
and their product.

- Peter

Peter T. Parrish, Ph.D., President
California Solar Engineering, Inc.
820 Cynthia Ave., Los Angeles, CA 90065
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parrish at calsolareng.com 

  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Carl Emerson
Sent: Tuesday, March 24, 2009 5:20 PM
To: 'RE-wrenches'
Subject: [RE-wrenches] MPPT greater than 150V

Hi there,

Can someone confirm that there is still no MPPT regulators available capable
of accepting array voltages greater than 150.

Thanks,

Carl Emerson

Free Power Ltd.

Auckland NZ

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