Non political off-topic. Solar water heat. - RC Groups
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Sep 15, 2003, 10:47 PM
El Queso Grande

Non political off-topic. Solar water heat.

How difficult is it to add a solar water heater to an existing system? Anyone done this?
Sep 16, 2003, 12:59 PM
zippogeek's Avatar
I was looking into this not long ago. High up-front $$$ with a looong time to payoff. Check out this site: solar panels cost a LOT, plus you need special pumps and collectors. A lot of maintenance too, I bet.

Technically I think it's easy. But just not practical in Buffalo where 2/3 of the year the sun shines just a tad more than in Alaska! My buddy Ron (Skeetpf) did something cool for heating his pool, whereby he circulates water into a black 3" flex hose (maybe 30-40 ft. long) that's coiled on top of his black-shingled shed. It absorbs sunlight, and the fact that the water is dispersed allows it to warm up before flowing back to the pool. He says he gets a good deal of free heat out of it. A similar system:

Good luck!

Sep 16, 2003, 01:19 PM
El Queso Grande
Thanks for the links. Payback in 4-7 years is awesome. I'm gonna have to start investigating this more closely.
Sep 16, 2003, 01:28 PM
Endangered User
MattLarson29's Avatar
If only GWB hadn't, or, wait, if Clinton hadn't, or was it the NeoCons? Oh, this is supposed to be a nonpolitical thread!

Seriously, though, have you checked into the tax credits you can get for alternative energy? I thinkthe feds have one, and some states as well. Might help offset the initial expense.

Sounds like a cool project. So what size Hacker will you use to pump the water?

Sep 16, 2003, 01:53 PM
Registered User
Hey it was very easy in Fla. (and soon again here in AZ) I just hooked up a thermo-syphon system (holding tank above collector) and plumbed that in to the cold water entry side of the regular hot water problems and pay back was just about 4 yrs...(homebuilt system....and plenty of sun in the lower latitudes)
If your part of Oregon is not in a feeze zone then that simplifies things a lot. If not then you need either a drain back system or one that uses antifreeze in the collector. With the former being less complicated.

Sep 16, 2003, 01:59 PM
Forever TMWT Pilot #11
LcJ's Avatar
But are we using up the sun faster by using it's energy?

Just joking.

Latest blog entry: RC Logger's Eye One Xtreme Quad
Sep 16, 2003, 03:12 PM
El Queso Grande
We're definately in a freeze zone and any collector will be shaded part of the day in the winter but still....just hoping to rig something up to help the hot water, not replace it. I'll look into tax credits but it may not apply to a home-built system.
Sep 16, 2003, 05:59 PM
Registered User

What really counts is the amount of sun BTUs you can collect at your location....

.... I don't know if Oregon gets all that much sun and you could be looking at a suuuuper long payback time. Best to check for consumer reviews in your area >before< you invest any cash!
Sep 16, 2003, 06:25 PM
Tacoma, WA, USA
William A's Avatar
My brother inlaw enlisted me to dig up info on this a while back,
he was thinking along the lines to help him heat his pool.

Here's some links I collected. I believe I pulled them off Google.
Sep 16, 2003, 06:38 PM
Registered User
For a rebate in Oregon the System needs to be
OG 300 Certified.
Hood river area will freeze so you'll need to run an
anti freeze system with pump and heat exchanger.
If you can get the tank above the Collector you
can eliminate the pump.
The newer circulation pumps from El Sid however
run as little as 20 watts. (a cheap solar panel)
(Their brushless ) and spendy $140

Here are links to Oregon Dept of Energy on Solar
Sep 16, 2003, 10:01 PM
El Queso Grande
Thanks guys.
Sep 17, 2003, 01:36 AM
Registered User
A simpler approach would just be a water pre-heater.
Its nothing more than a water tank painted black set in an insulated box with double pane glass on the top.
Simple, no pumps or anti freeze and just use normal
water pressure.

Look about 3/4 way down this page on other features.
(rest of site is interesting also)

On a side note: I dont trust the cert process much for
solar water htrs. Some that are certified have Poor
performance. A guy who tested alot of them said once
one of the most efficient he saw was 2 Truck radiators
painted flat black in an insulated box....

Sep 17, 2003, 03:51 AM
Registered User
downunder's Avatar
I'd suspect the cost/complexity of adding solar to an existing pressurised system would vary with whatever type you had. When I had my house built about 22 years ago I specified solar from the beginning. Hot water is gravity fed from a tank in the roof. I'm at the same (Southern) latitude as central Tn and solar does all the heating for about 6 months then it's almost like a switch is turned off. This may be because the incident sunlight reaches a critical point where it just gets reflected rather than passing through the glass. Heating is then done by an electric booster so you could say the roof tank is then a giant kettle!

One problem I've found is that after a few days of hot weather (100+) the water out of the tap is dangerously hot. Hot water, in Australia at least, is supposed to be regulated to a max of about 150F but with unregulated solar I've had it up to 180F.

Personally I think the best system would be a gravity fed solar with an on-demand gas heater for those winter days.
Sep 19, 2003, 02:04 AM
cobalt's Avatar
downunder, your avatar looks sort of familiar...

Sep 21, 2003, 12:22 AM
Registered User
downunder's Avatar is a bit familiar. I'll never forget driving along a dirt road with a flock of those things pacing alongside me