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Is My Solar Water Heater Working??? - Page 3

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Posted by Thomas Flannigan on May 1, 2006, 2:58 pm
Thanks very much for the helpful posts.  yes, I have Fireball collectors
from Solarroofs and I believe it is an El Cid pump.  I am at work today
but will check tonight.
     Last Wednesday, Thursday and Friday we had sun and the pipe from
the Solaraide tank to the backup gas tank WAS hot.  Since then the sun
has not come out so the system has not been on.  I went on the roof
Saturday and rearranged the direction of the PV panel.   A neighbor has
some big trees blocking sun in the afternoon that he said we can trim,
but we have not gotten them trimmed yet.  That meant the PV panel kept
the pump going after the collectors were shaded and we were only getting
about 2 1/2 hours of direct sun on the collectors until the shade
blocked the light.  Now the PV panel should shut off around 1  or 2 PM,
same as the thermal panels.
    The pipe insulation covering the line out from the collectors to the
tank melted and burst like hot sauasages.  Only the first 5 or 6 feet
popped and they copper pipe turned a bright pink which you can see if
you scrape off the melted insulation goo. The line in the shade of the
house going down from the roof to the basement (22 feet) seems OK.
   Our neighbors, after initial scekticism, seem interested, so solar
eenergy may actually reach Chicago's northern subsurbs if this works!
Tom Flannigan   Listless in the Loop

Posted by dold on May 1, 2006, 7:44 pm

Is this http://solarroofs.com/purchase/sys5.html  $360 with tank?
And you had an existing 80 gallon gas water heater?

I am considering the 2 collector system at $860.  I might put that tank in
place of my existing 50 gal propane-fired DWH, and use a tankless heater as

Good news, bad news.  At least it works when it ought to.  

Okay.  You had the PV sunny when the panels were shaded.  That would run
tepid glycol into the tank, removing some of the heat you had gained.
I see a description of a timer or differential controller in the owners'
guide.  Which do you have, if either?  I would think that the pump turning
on and off as PV was available would be enough control, except maybe
overtemp.  You must not have a differential, or it would have stopped
pumping as soon as the collectors were shaded.

Hmm.  Unless you are going to take a shower at 2PM, I think you need to do
something about the panels.  That's an early cutoff, and you sound like
your sun is marginal anyway.

Because I also have a Time-of-use meter and PV solar panels, I would want
to gear my DWH toward the late afternoon, so that washing and showers
could be in the evening.

What happened there?  I see that the kit comes with only a sample piece of
high temp insulation.  Was the wrong kind of insulation used on that pipe?

Clarence A Dold - Hidden Valley Lake, CA, USA  GPS: 38.8,-122.5

Posted by Steve Shantz on May 1, 2006, 11:31 pm

Solar hot water heaters are almost like magic when you put your hand on
a pipe and it's hot.  I could sit (and have done it) for an hour and
revel in the mystery of heat captured from the sun. Especially last
week when we had 4 sunny days in a row! Rare event in northern Indiana.

But when things are not going as expected...

The shading is definitely a bad thing.  Trimming the trees ought to be
a priority.  Your very best heat comes in the time window between 2
hours before and after the sun reaches the highest point in the sky.
However, there is still lots of heat to be gained in the next hour and
a half both ways outside of this time window.

The high temperatues and melted insulation suggest other problems as
well.  As mentioned in a previous post, I suspect that your flow is to
low.  What is the model # on your El Sid pump?  If it is SID 10, it is
likely too small.  It should be a SID 20.  Also, after SID 10 (or 20),
it should say PV, not B.  If you have a SID 20 PV, I think you need
about 30 Watts of PV to drive it.  You can watch the little red LEDs on
the El Sid pump to determine when it is pumping.  Steady lights mean
the pump is turning.  Blinking light means it is trying to get going.

I looked up info for your system (or what some are guessing your system
is), and the installation diagrams and technical information seem a bit
vague.  There is not a clear indication as to the power of your pump
(10 watts or 20) nor a clear guidance as to what is the power of the PV
panels.  Info on Fireball 2001 panels is also a bit vague, but the
diagrams I saw seem to indicate that flow through the panels is in
series.  Bad design, if what I gathered is true!

The collectors must be plumbed in parallel, otherwise the pressure drop
will be to high, giving very low flow rates and very high outlet
temperatures (which would melt the insulation).  El Sid pumps are great
circulators at low pressures, but flow rates drop off very quickly when
the head pressure builds.

I hope this is helpful for you.


Posted by Thomas Flannigan on May 5, 2006, 6:11 pm
 Yes, I have the Fireball system from Solar Roofs.  They have been very
helpful with tech support and I have gotten 140 degrees a couple of
times when conditions were good.  The nice thing about this system is
the collectyors; they are light and easy to haul up onto the roof.
   The plumber was out again this morning and we recharged the line and
got the proper 50 PSI in the expansion tank.  It worked great for 10
minutes then the clouds came.  I think it is fixed.
    Yesterday, I went on the roof to "bleed" air out of it and got a
blast of boiling hot glycol in the face.  Glad I was wearing glasses and
I was not injured.
   I will check about the type of El Cid pump.  It does not have lights
on it that I can see.
    Once the neighbor's trees are trimmed I will reposition the PV panel
due south and hopefully double hot water production.  With the two
little girls spilling and urinating all over everything the hot water
will not go to waste.
Tom Flannigan

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