Solar hot water?

[William P.N. Smith]

I thought my builder had the solar hot water thing under control, and
he thought I was doing it, so now I've been saddled with another task.
Sometime in the next month I've got to get a solar thermal hot water
system specified and delivered. Yikes!

Anyone have any suggestions for brands, vendors, or types? This will
be used in a non-freezing environment, and I'd like to get as much
storage as possible.

Because of homeowner's association rules, the solar panel must be at
ground level, and I'm thinking of having an 'automatic' system that
will use a couple of 20W solar electric panels I've already got,
running a circulation pump whenever the sun shines. Will this work,
or must I have a differential thermostat as well?

Can I just use any random electric hot water heater(s) for storage,
and run the heated water backwards thru them with a pump, of do I need
to remove/extend the drain valve to take cold water from the bottom of
the tank?

Anything I'm forgetting?

Many Thanks in advance!

 

[wmbjk]

I thought my builder had the solar hot water thing under control, and
he thought I was doing it, so now I've been saddled with another task.
Sometime in the next month I've got to get a solar thermal hot water
system specified and delivered. Yikes!

Anyone have any suggestions for brands, vendors, or types? This will
be used in a non-freezing environment, and I'd like to get as much
storage as possible.

Because of homeowner's association rules, the solar panel must be at
ground level, and I'm thinking of having an 'automatic' system that
will use a couple of 20W solar electric panels I've already got,
running a circulation pump whenever the sun shines. Will this work,
or must I have a differential thermostat as well?

You'll probably need at least an upper-limit cutoff. In summer our
setup (AZ, 64sq.ft. collector, 2 people) only circulates for about an
hour per day, and that's with a 160F storage limit. FWIW, I had a
simple drain-down system for years in CA, and was occasionally
frustrated that I needed aa chart and an Ohmmeter to measure the
temperature sensors in order to figure out what the controller was
trying to do. So when it came time to build a new one I opted for a
differential controller with a digital readout of storage and
collector. About $200 IIRC.

Can I just use any random electric hot water heater(s) for storage,
and run the heated water backwards thru them with a pump, of do I need
to remove/extend the drain valve to take cold water from the bottom of
the tank?

There are custom solar/electric tanks with optimized ports. Sometimes
a separate tank is used for solar storage, in series with the existing
tank. You might check out the Solar Sidebar and batch heaters. Both on
this page
http://www.cisolar.com/catPool.html Good prices on collectors here
http://www.sunraysolar.com/index.php The guy is friendly and helpful,
he might even have some ideas on tanks etc.

Anything I'm forgetting?

Are you sure about not needing freeze protection? The collectors can
freeze fairly easily on a cold windy night.

Wayne

PS Please let us know how the energy detective thing works out.

 

[William P.N. Smith]

You'll probably need at least an upper-limit cutoff.

Yeah, I realized that's going to be important (as is I gather a
temp/pressure relief valve at the collector), so I've talked to the
electrician to get a wire out to the collector.

differential controller with a digital readout of storage and
collector. About $200 IIRC.

Good point. I've seen ones with a computer interface and electric
heater element control, but I'm not sure if I need to get that carried
away. I'll probably try for a couple of remote LEDs for circulation
pump and electric heater status, though... Any particular brand you
can reccomend, or just whatever comes with a complete system?

There are custom solar/electric tanks with optimized ports.

Everyone seems to use/resell the Rheem tank with or without an
auxiliary heater, so I'll probably go with one of those.

http://www.cisolar.com/catPool.html Good prices on collectors here
http://www.sunraysolar.com/index.php The guy is friendly and helpful,
he might even have some ideas on tanks etc.

I'll check those guys out, thanks!

Are you sure about not needing freeze protection? The collectors can
freeze fairly easily on a cold windy night.

This location has had a low temperature in the last 5.5 years of 63.04
degrees F. 8*)

PS Please let us know how the energy detective thing works out.

Will do, but it may by June or July by the time I get it installed.
I'll remember to take pictures!

 

[wmbjk]

Yeah, I realized that's going to be important (as is I gather a
temp/pressure relief valve at the collector), so I've talked to the
electrician to get a wire out to the collector.


Good point. I've seen ones with a computer interface and electric
heater element control, but I'm not sure if I need to get that carried
away. I'll probably try for a couple of remote LEDs for circulation
pump and electric heater status, though... Any particular brand you
can reccomend, or just whatever comes with a complete system?

Ours is a Heliotrope General Temp Trak II. Two storage sensor inputs,
1 collector, and 2 aux IIRC. Nicely customizable with dip switches and
pots, with digital readout of settings and sensor temperatures. Either
storage sensor can be used to govern circulation. Freeze circulation
option for direct systems that need only occasional protection. It's
been trouble free, my only (minor) complaint is that the
select-function button is quirky. Sometimes nothing happens when you
press it, other times it jumps two steps with each press. The
controller is about 7 years old, I don't have any idea what newer
versions are like or what else is even available. And I don't remember
it having any aux heater functions.

Everyone seems to use/resell the Rheem tank with or without an
auxiliary heater, so I'll probably go with one of those.


I'll check those guys out, thanks!


This location has had a low temperature in the last 5.5 years of 63.04
degrees F. 8*)

I thought you were in MA? Maybe you need to close the doors at night,
it sounds like you're heating the outdoors.

Will do, but it may by June or July by the time I get it installed.
I'll remember to take pictures!

Looking forward to it, I might get one too. According to the MX60
we've had a few days with >500 minutes of float time, and many with

200. Gotta' get to the bottom of that problem ASAP. ;-)

Wayne

 

[[email protected]]

Ours is a Heliotrope General Temp Trak II. Two storage sensor inputs,
1 collector, and 2 aux IIRC. Nicely customizable with dip switches and
pots, with digital readout of settings and sensor temperatures... The
controller is about 7 years old, I don't have any idea what newer
versions are like or what else is even available.

It's no longer being made. OTOH, we can put a $6 snap-disk thermostat
inside a glazed box, with another high-limit thermostat on the tank.

Nick

 

[wmbjk]

What an incredibly long path. Looks fishy.

http://groups.google.com/advanced_group_search
William P.N. Smith
0 posts in the last year

Troll.

Alan

You already made the same stupid claim here http://tinyurl.com/zcy7w,
and I corrected you here http://tinyurl.com/kurk5. Now tell us, are
you a just a slow learner, or the world's slowest learner?

Wayne

 

[William P.N. Smith]

newsspool2.news.pas.earthlink.net!stamper.news.pas.earthlink.net!stamper.news.atl.earthlink.net!elnk-atl-nf2!newsfeed.earthlink.net!nx02.iad01.newshosting.com!newshosting.com!195.62.97.14.MISMATCH!newsfeed0.kamp.net!newsfeed.kamp.net!news.osn.de!diablo2.news.osn.de!ecngs!feeder.ecngs.de!216.196.110.149.MISMATCH!border2.nntp.ams.giganews.com!nntp.giganews.com!news.astraweb.com!newsrouter-eu.astraweb.com!hwmnpeer01.ams!hwmedia!news.highwinds-media.com!feed.xsnews.nl!feeder.xsnews.nl!sn-ams-06!sn-xt-ams-08!sn-post-ams-02!sn-post-sjc-01!supernews.com!corp.supernews.com!not-for-mail

Hey, I'm _glad_ it's a long distance between my universe and his. 8*)
Netherlands and Germany to get between SuperNews and Earthlink, whoda
thunk it?

Ah, my mistake again, I keep forgetting I don't exist. Wonder if
Google can find my !decwrl!sandbox!wpns postings, from the late
80's... The Invalid probably doesn't even know what bang path
addressing is, sigh.

Thanks again for affirming my existance, Wayne. 8*)

 

[William P.N. Smith]

Not one chance in hell I'll ever read one of your articles,
nor any responses to them. Won't even download those articles
from the server.

Ooh, he's got an offline newsreader, everyone stand back in awe.

[Except for Google, are there any newsreaders that _aren't_ offline
readers?]

Careful, he's a Eunuchs Guy! 8*)

 

[wmbjk]

<article not downloaded:

You were undeniably dead-wrong about Smith, twice. Now you're
responding to corrections you conveniently claim not to have read. In
honor of your spinelessness and transparency, Usenet Head Office
hereby declares that you shall henceforth be known to one and all as
the Inspector Clouseau of headers.

Wayne

 

[wmbjk]

Ah, my mistake again, I keep forgetting I don't exist. Wonder if
Google can find my !decwrl!sandbox!wpns postings, from the late
80's... The Invalid probably doesn't even know what bang path
addressing is, sigh.

Thanks again for affirming my existance, Wayne. 8*)

"Existence is futile, you will be pretermitated"

- Inspector Clouseau, invalid header detective


Wayne

 

[William P.N. Smith]

Can anyone figure out what The Invalid is talking about?

$ host 4ax.com
4ax.com A record currently not present

Gee, whois thinks it's owned by forte, wonder if that means anything.

The post can't be from there.

You might want to do a bit more research.

One can easily create phoney message ids with Forte Agent.

And Agent will automatically create real ones too. You have APN too,
Wayne?

[More blather about (incorrectly) dissecting headers, I bet his mom is
proud.]

And when someone starts making them look like the ignorant
bozos they are, they bring in their sockpuppets in an attempt
to bully that person or persons.

Ah, foreshadowing. 8*)

If he was an ordinary Usenet citizen, with the integrity to
post under a single unique alias

Who are we talking about again? Oh, yeah, The Invalid, who doesn't
post under his real name, and doesn't provide an Email address, is
concerned about the integrity of those of us who do. 8*)

That's another reason I make trolls wear gags when they are
in my newsreader.

Oh, now he's scaring me.

This reminds me of the person who was once going to complain to the
Usenet Administrator. 8*)

 

[wmbjk]

Can anyone figure out what The Invalid is talking about?



Gee, whois thinks it's owned by forte, wonder if that means anything.


You might want to do a bit more research.

Or a lot less. All his "research" so far has only caused him to draw
bizarre conclusions. Combined with his immunity to undeniable proof of
his errors... hey, now I see how solar power consultants and religions
get started!

This reminds me of the person who was once going to complain to the
Usenet Administrator. 8*)

I hope this guy tries that as well. I've instructed the Administrator
to redirect all Clouseau missives to the DMV.

Looking forward to his next "article xxxxx not downloaded, no reality
allowed into my PC" response.

Wayne

 

[JoeSP]

I thought my builder had the solar hot water thing under control, and
he thought I was doing it, so now I've been saddled with another task.
Sometime in the next month I've got to get a solar thermal hot water
system specified and delivered. Yikes!

Anyone have any suggestions for brands, vendors, or types? This will
be used in a non-freezing environment, and I'd like to get as much
storage as possible.

Because of homeowner's association rules, the solar panel must be at
ground level, and I'm thinking of having an 'automatic' system that
will use a couple of 20W solar electric panels I've already got,
running a circulation pump whenever the sun shines. Will this work,
or must I have a differential thermostat as well?

Can I just use any random electric hot water heater(s) for storage,
and run the heated water backwards thru them with a pump, of do I need
to remove/extend the drain valve to take cold water from the bottom of
the tank?

Anything I'm forgetting?

Yes, you're forgetting that solar-thermal is much more efficient than
solar-electric. Unless you want to mortgage the house on a photovoltaic
array just to run a small heating element, consider one of the many solar
water heating designs that have been around for the last 3 decades or so.

 

[Jim Baber]

Jim's comment to JoeSP

Yes, you're forgetting that solar-thermal is much more efficient than
solar-electric.

Joe , I don't see any reference to Bill wanting to heat the water with
the panels, he specifically stated that the PV panels were to run a
recirculation pump. I have seen this on several proposals for solar
domestic hot water systems. I also have noted where people have
suggested electric water heaters for storage tanks, specifically
intending to only use the electric elements as a fall back heat when
there was insufficient solar water heating because of weather or the
time it was needed.

Unless you want to mortgage the house on a photovoltaic
array just to run a small heating element, consider one of the many solar
water heating designs that have been around for the last 3 decades or so.

--
Jim Baber
Email [email protected]
1350 W Mesa Ave.
Fresno CA, 93711
(559) 435-9068
(559) 905-2204 (Verizon IN cellphone (to other Verizon IN accounts))
See 10kW grid tied solar system at "http://www.baber.org/solarpanels.jpg"
See solar system production data at "http://www.baber.org/solar_status.htm"

 

[William P.N. Smith]

Joe , I don't see any reference to Bill wanting to heat the water with
the panels, he specifically stated that the PV panels were to run a
recirculation pump.

Yeah, that's what I was looking at, to save wiring and such.
Unfortunately, I really wanted all the fancy features of the good
controller, including overtemp shutdown, so I'm going to have to run
conduit out to the (solar thermal) panels. The AC power for the
circulation pump is something like 20 watts, so I'm going to just plug
it in.

I'm gonna (if I can afford it) put panels up in a grid-tie
configuration later, which will hopefully take care of all my baseline
load.

I've got (what I think is) a good system on order from
http://kingsolar.com/ with all the bits and pieces I'll need. I'll
let you all know how it comes out. It includes a Rheem solar storage
tank with backup heater and four ports (domestic water in and out and
solar loop in and out), which appears to be a much better solution
than modifying a standard hot water heater...

Thanks for all the feedback, guys!

 

[William P.N. Smith]

I think you need two tanks for hot water... a big tank like 120 gal for
the solar, and a little tank like 20 gal for the electric backup.

They have setups like to to add solar preheat to your existing hot
water, but this is the only one. I figure I'll set the electric
elements to something close to 120 and let the solar heat it to 160 or
so. I've got a tempering valve on order, but I've been less than
impressed with my first exposure to them (if was flow was really slow,
water was really hot!).