Solar Hot Water Heater

Eric Johnson_3

Anybody know of a website or message board where I could get more information on building one?

I'm thinking of putting one in my greenhouse this summer. Would 3/4-inch copper fin & tube baseboard core be a good thing to use for a collector element?

Dave_4

you can buy solar collectors that mount on your roof and then buy the storage tanks that have the heat exchangers built into them.

you would have to run a glycol through them if your in a area that gets winter. other then that solar hot-water heat works good. and if your a pro you can install the system yourself for a good price if you have radiant floor heating solar may be a good way to heat your entire house for free.

i was thinking of trying it but still stuck on how well it will work at night in the winter i don't think my storage tank will stay warm all night if my pumps for the infoor are running all night so id still have to tie it into my boiler? i hope to get some info from someone here on making it work it could save me $1000 on oil a year and the system if i install it would cost about $5to7k this system would pay for itself in 5 to 7 years and I'm free of oil after that. sounds good i just hope i can do it money is no problem for me.

thanks good luck
Jason

cphillips

new house dhw and space heating with solar

i'm building a new house this year and i'm trying to figure out the most efficient (both energy and cost) heating system...i plan to have radiant tubing in the concrete slab floor, and solar dhw (maybe)...can i heat the house with the solar water system? how much harder is that? is it worth it? but what as back up? (i live in ohio...winters and cold and overcast)

i appreciate any advice!

Dave_4

i think you have a better chance then i do with radiant floor in concrete i am planing on putting my 3/8 pex under the floor with plate's and then insulate under the floor with r19. but your concrete will hold it's heat well

thanks
Jason

Eric Johnson_3

a link!

Here's a pretty good link explaining the basics. Apparently there are much better things to use for heating elements than fin & tube. 1/4-inch copper sandwiched between black chrome plates would be the top-of-line rig, I gather.

I heat with wood in upstate NY, inlcuding DHW and it's a cause for celebration in the winter every month with the gas bill arrives, cause it's usually about $20. I'd like to keep sticking it to the utility in the summer, which is why I'm thinking about solar. Plus, I already have the greenhouse, so it would be kind of like having a solar collector within a solar collector. Actually, that's exactly what it would be.

John L

solar

Eric, where is the link you mentioned? This link may be of help. http://www.knowledgepublications.com/sunshine_to_dollars_google_adwords2.htm

Solarstar

Re solar : don't be misled by lots of solar output in the winter IF you have poor sun you will get peanuts for heat and you will be disappointed and therefore dissatisfied...Paul

ALH_4

Low Temp

Anyone using a "low temp" heat emitter, such as a radiant floor, concrete, extruded plates, warmboard, etc., is the best candidate possible for heating with solar panels. The system consists of solar panels, a storage tank with the appropriate number of heat exchangers inside, and a control to determine whether to use the solar heat or the conventional heat source. Sizing of panels, tank, exchangers, etc is best performed by an experienced professional. The use of a low temperature heat emitter is important, because it maximizes the usable heat that can be stored in the tank (maximizes the tank delta-t). Solar domestic hot water heaters are frequently the application with the shortest and most predictable payback. The incoming water is always cold, and the tank is cycled every morning, matching the diurnal output of the solar panels. This is usually done with a pre-heat tank ahead of the conventional water heater.

Using baseboard elements as collectors is probably not the most efficient way to collect solar energy. Collectors have specific coatings and glass in order to maximize the efficiency of the panel. Also the fins on the baseboard elements are approximately parallel to the sun's rays, which nearly eliminates any benefit increased surface area of the fins might have.

-Andrew

Eric Johnson_3

the link

Sorry about that. Here's the link:

http://www.thermomax.com/Solar Hot Water.htm

I've modified my thinking over the past couple of days and more or less decided to buy a manufactured collector and do the rest of the installation myself. I think the gain in engineering and efficiency and the likelihood that it will work, is worth the expense. Installing it and getting it working the way I want it will be enough fun.

Plus (here's the great part) everything is half price!

Turns out you can take a federal tax CREDIT of 30% of the cost of materials (not sure about installation) up to $2,000. Plus, I live in New York State, where you can take a 25% income tax credit, plus pay no sales tax, for a total of up to $5,000. The federal part is calculated after deducting the state credit, but it still nets out to more than a 52% discount, not including the sales tax incentive.

I had my wife convinced before I learned about the credits, so this is looking pretty good.