homebrew vs brand solar heaters

[bewotec]

Hi,

I would like to ask you for opionion only. If there is someone who has experience with brand solar heater and homebrewed ones also.

Is there noticable effincincy difference between these? I mean in cold winter days how much higher is the brand solar heater temperature than a homebrewed (copper pipe, black painted, glass covered)? The price is about 4:1 so thats why i am interested in it...

thanks for any comment,

viktor

[thebbqguy]

Hi Vic,

Well, good question ! ,

I just bought a professional solar system made by Enersol last week, and it's expected here at my house today !

I bought one panel - a 4x10 size - so that's 40 sq feet.

I'll see what kind of heat I get out of it today.  I was going to buy a few of them, but thought maybe I should try one first, and see how better it is than my homemade systems.

Anyway I'll be posting images of the professional one maybe today or tomorrow.

you can see my homemade systems here:

http://www.powershotgraphics.com/pool

http://www.powershotgrahpics.com/pool2

in the second one, - I have now redone the tubing and have coiled it properly

in the box you see there ( the enclosed box that has plexiglass )

Mark.

[thebbqguy]

Hi Viktor, sorry for the mis-spelling on your name.

You asked for an opinion, and i didn't quite do that in my first post.

I have spoken to several people on websites that sell professional systems, and they all say that you cannot even begin to compete with a professional system.

I do tend to agree.

Why ?

Because they make use of the sq.footage of an area, 100%, a 4x10 sheet = just that, 40 sq.feet

I have a 4'x8' sheet of plywood - in theory that's 32 sq. feet, but....

much of my 4x8 sheet is not usable, the corners, and also the middle where I was not able to bend the pipe, and had to stop my coil there, - so in reality,

that 4x8 sheet of plywood with blackpipe has a LOT of wasted space.

Look at the image below.

Also, let's remember that most black pipe homemade systems are 1/2" pipe....

the professional ones are 1-1/2" pipe ! .... the gallons per hour these things push out is unbelievable, so there's just no comparison.  I like tinkering, and don't have tons of money so I made 3 homemade systems, but scraped up money to buy one professional panel to test, and keep.  I have put in all the tubing this week, in anticipation of my professional solar panel's arrival. I have it running from my pool's pump, under the deck and into a part of the backyard where I'll put the solar panel on the ground and test it.

[wdyasq]

I think the real product missing is the Dollar per Unit of energy acheived.  A more personal unit might $ per unit ENJOYED.

While the folks with the high efficiency hot water heaters can claim X Btu/sf/hr they can't match the pleasure of a warm shower from a dark colored hose simply warmed by the sun.

Ron

[Norm]

    Has anyone ever just pumped water onto the top of a roof...let it run off into the eaves and into an open container like a horse trough...cistern, or whatever? About the cheapest way I can think of to get hot water ...also your attic wouldn't get so hot! Norm.  

[thebbqguy]

HI Viktor,

As promised here is a pic(s) of my new solar panel.

I AM impressed with it, and it blows away my homemade one, that's the sad part, but I am glad, as I paid good money for this one :-)

In one image I talk about the flow rate... the professional panel is 1-1/2" so no wonder it put so much water out - now we're cooking with gas, I mean solar :-)

Considering this is only one panel, I can't even fathom what 5 of these would do on my roof, - I do now believe my brother when he said a guy's pool was at 94, and that the guy has to turn the solar system off and can't keep it running all day, - the water flow when 4 panels are hooked up together is amazing, considering that each panel can handle a lot of water.( 10 gallons MAX per minute per 4 sections) - which I have here..... but I don't have it running at 10 gpm.

To seriously heat my pool I need at least 4 of these panels, which are 4'x10'.

[bewotec]

Hello,

is this DIY kit also a non-glassed one?

so only because of the good engineering and the satisfying material, it has 4 times better efficiency than the homebrewed one.

i am impressed and sad also.

thanks!

viktor

[troy]

The key difference between the commercial unit and the homebrew unit is the average length of run.  It looks like the commercial unit has many pipes of short length in parallel, while yours is one long pipe.  Might be interesting to do those temp measurements on your unit to see what the temp is as you go further down the pipe.  If you stop gaining significan heat at 40 feet, you could just make yours a lot of shorter parallel pipes like the commercial unit.

Best regards.

troy

[thebbqguy]

Hi Troy,

Interesting, yes I would love to measure that.

I will tell you though, for the homemade systems, the longer the tube the better.

I know just from experience.... I made a smaller solar system, - incased in a box, and I have now given up on it, - even with the plexiglass, the amount of tubing I used, about 120 feet, is just not long enough to do any real heating.

My local pool places sells "homemade" systems just like this using the exact same black tubing ( which is available at all hardware stores ) and they recommend a minimum length of 500 feet.

When I bought my own tubing it came in a 400 feet length.  I remember testing the water, and water temp was so-so.... so I bought another 200 feet and added that to the 400 .... guess what .... water temp was MUCH higher !

but yes, you are right on the money, there IS a a point where the tubing stops being effecient in terms of heat vs the length, but what that length is, I just don't really know exactly.

Mark.

poolguy@powershotgraphics.com