Solar question

David Woycio

Sounds like a flat plate collector, my favorite. 4- outlet? What size? Rule of thumb, 1.5 gallon of storage sized per 1 sq. ft of collectot area for domestic hot water........ 40 sq ft of collector will heat 60 gallon storage.

Tony_23

solar DHW

If you use an indirect for transfer to domestic, and a collector similar to a pool heater, what do you use to keep the collector solution from boiling off ? Or blowing off ? I've read guys saying these setups could get to 300F and am curious how you protect against that.

A good book in the "Shop" might sell

TIA,

Tony

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Ron Huber_2

Book

Solar Hot Water Systems: Lessons Learned 1977 to today by Tom Lane, do a search and you can find several places to buy on the internet. Closed loop with a presseure only relief valve (watts makes an adjustable one up to 150 psi) set for 90 psi. There are a few other ways of dealing with stagnation problems that are covered in his book, vacation by pass being one of them. Photo of current Viessmann DHW install.

Tony_23

Thanks Ron

I'm thinking a closed loop w/ glycol mix heating an IDWH. Cycling the circ on temp of the collector.

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Ron Huber_2

Viessmann

and other brands have dual coil tanks, one for boiler and one for solar, although I prefer the two tank system. Viessmann also has a differential control to operate the system automatically, there are also a few other brands out there

hr

A simple system

I've been doing closed loop glycol systems for 20 years now. Think of the panel as a small boiler.. you need an air removal device, expansion tank, relief valve, check valve, pressure gauge and a means to fill and purge.

A flowmeter is a nice option also. Preheat tank for DHW is a good application. Combining with heat gets more involved.

Go to www.pmengineer.com and look in the archives for Siggy's July 2006 article "The Sunny Side of Hydronic Heating"

Most of the online solar stes have piping drawings www.thermomax.com www.schuco-usa.com are a few.

With a full day of sun this 40 gallon Bud has been hitting 160F coupled to a 24 square foot panel.

Also my very first evac tube system. Easily installed on this steep pitch roof. A Vaughn 80 gallon stone lined tank for preheat.

hot rod

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David Woycio

solar

Pool heater??????? Are you talking about the PVC type? Temps are quite a bit lower on these than a flat plate.

I perfer drain back water systems for many reasons. Careful on what indirects you use. SuperStor for example defines a commercial tank installation as using 150*F or higher set point. Warranty for this application drops from lifetime to 6 years!

A nice fit is a drain-back tank with an indirect. Eliminate lots of problems. Got some info on our web site if your interested..... www.metro-solar.com

Go solar & Good luck!

Tony_23

Copper

NOT PVC. Copper tubes that appear to be soldered to a plate in a "box". It heated a pool 18' in diameter w/o any help. I'm just looking to preheat my domestic.

And, since it's my house, warranty is not much of an issue. I like to guinea pig myself, but my wife's not always crazy about it

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hr

Dave, can you make this training?

all others invited.

hot rod

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David Woycio

shuco

They're trying to get me up there. Would like more info b4 I take the time. My 1st question is how do you replace the glass. Looked at some other flat plate solar collectors (German). Asked the rep and after some moon-walking he said the entire panel would have to be replaced if glass broke, or riser leaked, or ???

Makes a HO nervous with BB gun toting teen next-door.

If I do go I will let you know.

BTW I like your portable solar DHW trailer. When is the radiant, pool, hot tub, snow melt version coming? May have to add another axle.

Joe V

How com solar...

heated water is not used to preheat steam boiler water?

Wouldn't there be a savings in bringing 160+ water to boil?

David Woycio

shuco

Yo Hot Rod,

Got a call from Shuco rep. He is supposed to be sending me some literature. From brief conversation system seems to be a serpentine styled absorber plate design. Glass is not changable.

David Woycio

solar boiling

Not many systems will boil water on a consistent basis in the middle of the winter.

Mean temps are around 130*F