Author Topic: Solar H2O Finally (Read 4909 times)

KEG · « **on:** September 21, 2007, 02:19:01 AM »

I started this project over a year ago, but the wind mill and live got in the way, I got the idea from a post Halfcrazy did and set out to find some glass and found a build that was being remodeled and talked them out of some old tempered glass , with the hopes it didn't have much lead in them.

started by making a frame out of 2" X 4" s and made a notch for the glass to set in, and cut the insulation to fit, and started to solder the copper.

once it was soldered up covered the insulation with foil tape, and ordered some emission plates.

the emission plates are for hydronic heating and fit over the 1/2" copper tubes real tight, once those where in it got a good coat of flat black paint, and them a coat of oil base on the out side, and that is as far as I got until now.

got some 3/4" and 1/2" copper and made a 5" four tube heat exchanger so I can run glycol threw it in the winter and not have to drain it, silver solder is not one of my stronger skills I found out.

got the panels mounted on the roof and run the lines down to the heat exchanger and tied that to the pre heat tank before the gas water heater, with a little luck I'll get some heat out of it this winter.

GaryGary · « **Reply #1 on:** September 20, 2007, 08:34:33 PM »

Nice!

I'm not familiar with an "emission plate"?

I guess its acts as the absorber? and transfers heat to the copper pipes?

How is the emission plate bonded to the copper pipes?

Gary

SparWeb · « **Reply #2 on:** September 20, 2007, 09:16:39 PM »

When you say you're running glycol through the pipe, and in the same sentence your soldering isn't your strong suit... you know glycol isn't exactly healthy, right?

Anyway it looks like the glycol is on the outside of the water tube with no joints in the water tube - fine if that's the case.

Gordy · « **Reply #3 on:** September 20, 2007, 10:20:11 PM »

Gary,

The emission plates are made of aluminum, for in floor type heating. Tubing (Pex)is run under the floor (wood) between the floor joists, the emission plates are friction fit around the tubing (snap on) then secured to the floor sheeting. The plates act like radiator fins to spread out the heat from the tubing. My local Menards has them in stock.

Gordy

KEG · « **Reply #4 on:** September 20, 2007, 10:34:12 PM »

Gary

they are made by Roth Industeries, they are a ridgid alum plate with a C shape extruded on one side to snap on the pipe and come in 4' lenghts

KEG · « **Reply #5 on:** September 20, 2007, 10:38:56 PM »

Steven

Very good, yes the domestic water is running threw the inner 1/2" pipe and it is a complete tube clear threw, just reamed out the stop in the top of the T's, it is leak free now I did a pressure test on both sides until I got all the leaks fixxed.

mungewell · « **Reply #6 on:** September 21, 2007, 09:04:40 AM »

What type of gycol are you running?

If it's 'washer fluid' you should be careful that a leak doesn't develop in future as it's highly poisonous. This is why I believe that you're supposed to have dual wall heat exchangers with an vented air gap, so that any single leak does't cause contamination and can be spotted quickly.

Another alternative is to use 'food safe' gycol which is non-poisonous, such as Dowfrost (although that's pretty expensive).

Simon.

GaryGary · « **Reply #7 on:** September 21, 2007, 09:08:29 AM »

Thanks -- I've used these -- I guess I just didn't know what they were called

Gary

bsafe · « **Reply #8 on:** September 23, 2007, 02:57:39 PM »

What are the outer dimensions of your 2x4 box? How long are your 1/2 runners and 3/4 manifold? Thank You, bsafe.

miata2k · « **Reply #9 on:** September 25, 2007, 10:23:25 AM »

KEG,

That is a great project, I think we are all interested in seeing your results. I have a few questions about the system, please point me to other documents if this is not your design.

Do you have any way to collect data from the collector and the heat exchanger?

I like to see some more information on the construction and efficiency of the heat exchanger.. I'm guessing you are just running small pipe through the larger pipe?

How did you decide on the size of the heat exchanger?

Would it be more efficient if you insulated the pipes?

It also looks like the heat exchanger has 4 pipes in parallel, did you consider consider putting them in series to make a longer device, to give more time for the heat transfer?

I see an expansion tank, I'm guessing it is for the pre-heating system, do you also have some type of pressure blow off valve?

Also what size and type pump are you using? I see a timer on the wall, I'm guessing you adjust it to run when you have sun.

Thanks,

-C

KEG · « **Reply #10 on:** September 26, 2007, 10:35:51 PM »

Besafe & miata2k

The box was made to fit the glass as it is real hard to cut tempered glass, but the out side dimension is about 4' 6" X 2' 6", the manifolds are made with 3/4" X 1/2" copper Tees and it is all made to fit according, to the center to center of the emision plates - glass - and box, it's all part of a puzzel or challeng,

the heat exchanger is 5' tall on the 3/4" pipes because four of them is what I could get out of a 20" length of pipe, on rocket science thereand just made the rest to fit, there is a relief valve up on the panel and the pressure tank is becouse the solar side is a closed loop system set to about 12 lbs presure, and yes the timer is the supper high tec part of the system, on at 8:00 am off at 6:00 pm rain or shine, I have seen it bring up the 55 gal. tank to 100 F it is just pre heating the water to the gas water heater, no data here just farmer enginering ;-)

This is the post that I got some of my info mation from and the idea, hope the link comes threw.

http://www.fieldlines.com/story/2006/4/9/14621/53240

git er done

Kevin

Ponderance · « **Reply #11 on:** October 25, 2007, 10:10:15 PM »

one question that does come to mind: Could it be mod'd to use plexiglass magnifier to concentrate light onto the copper tubing on the collector?

Ponderance · « **Reply #12 on:** October 25, 2007, 10:11:06 PM »

or at least a cheaper form of magnifier than plexiglass.....

freefuelforever · « **Reply #13 on:** December 06, 2007, 06:50:11 AM »

Wow, that is a lot of work. Looks good, too. Just curious-what did it all cost, not counting the hours of labor? Thanks!

huntedheads · « **Reply #14 on:** December 30, 2007, 08:01:20 AM »

Keg

I am building almost the same thing you did major differance the glass area is 34" X 76" double glazed not low "E" ( 4 sections when done ) and I have 13 vertical risers per section. My question is the heat exchanger you built? now that it's been in service for a while would you have done it differently now that you see how it works? Nothing aginst it I just had a completely different Idea and maybe I am wrong?

Do you have any data on exchanger input and output temp to see how much heat you are extracting at what temp storage and can you tell me the flow rate of the pump? I plan on a variable flow pump (home made) I know it will be divided by 4.

Thanks in advance,

MattM · « **Reply #15 on:** February 14, 2008, 10:23:37 PM »

Could that one-way window tint (see through one way and shiny-reflective the opposite side) for glass help trap light in the insulated chamber at all?

fcfcfc · « **Reply #16 on:** February 15, 2008, 07:05:39 PM »

Hi:

If you ever happen to see this being it is well after the initial post time, you might want to run your glycol in the center tube and your DHW on the outside. It will be more efficient. Also, I assume you are running the glycol and potable water in the opposite directions for the counter flow effect. I am referring to the HX here in both suggestions.

.....Bill

thyristor · « **Reply #17 on:** February 21, 2008, 06:36:10 AM »

Same here, don't know if this topic is still hot (no pun intended!)

I agree with your reasoning, also I don't think that the glycol can ever contaminate the water should a leak occur, because usually your water pressure will exceed the pressure of the circulating glycol, therefore you might have a situation where the water enters the glycol and not the other way round. (fairly safe, I would think).

getterdone · « **Reply #18 on:** March 14, 2008, 09:53:05 PM »

keg, i was reading one of your old posts and you said your silver soldering wasnt very good. the copper has to get almost cherry red, with 15% type. make sure the copper is clean by sanding., then flux male fittings. use acetylene and oxygen. or air acetylene turbo tourch. map gas just don't get hot enough. hope this helps in the future. and by the way how'd the system work? getterdone

News:

Author Topic: Solar H2O Finally (Read 4909 times)