hot water heating system

[Dave Speer]

Last year I bulit my own solar water heating system I have saved aproximately $1000 this past year on energy costs. Today it was sunny on the north shore of lake superior and about minus 10 c outside my system made 102f degree hot water from 0930 this morning until about 1600 this afternoon. This brought up my 40 gallon storage tabk up to 44 degrees c.
I thought there was a carbon calculator on this website but have not found it yet, can someone show me where to get a calculator.
thenks Dave

[Mario De Castris]

http://www.bp.com/extendedsectiongenericarticle.do?categoryId=900820 4&contentId=7015209

[John Allen]

Yo dave,

Congratulations on your solar heat system. Please tell us more details.

ja

[Dave Speer]

Hi John
I sure didn't invent my system the tech. has been around for a long long time.
I purchaced 2 used panels for $100.00 per. The rest though, like the heat exchanger and other things I built myself. The total costs were around $1400.00. I also use the system to provide home heat on sunny days during the fall, winter and spring. Also the storage tank keeps the water hot for quite a while. It's all about the BTU"s
My system isn't very handsome but it does the job. I have since put other systems in that work well and loof much better.
One nice thing about the do-it-yourself is the ability to scrounge lots of the needed material, and you get to know your systen better in case you have to troubleshoot. In my case a mistake caused me to have to rebuild my heat exchanger. I used black iron nipples wealded on to a 4" stainles steel pipe. They lasted 8 months before they began to leak. changed them to stainless and all is OK now
Cheers Dave

[Mark Parsons]

Greetings Dave,

I would love to pick your brain a little more. :cool:

I am installing one 3' x 8' panel this year. It looks very similar to yours. I too obtained it used. In my case for free. It is a vintage Norsun unit. I had to modify the configuration since the refrigerant had mostly leaked out. Testing now shows it to work very well.

A couple of questions, if you don't mind. I will be installing the unit on my cottage roof. It will be a drainback system.

You mention 4" Stainless Steel pipe. Seems large. I was hoping to use a less expensive pipe material to run from roof to basement for feed and return lines. I have sweated on copper threaded adapters for entry and exit to the flat plate collector. I was thinking of using hydraulic hose for the outdoor feed and return piping. Of course, drainback angles will be maintained to ensure water can't lock in exterior piping. I was thinking the thick black hydraulic hose may also provide some insulative value and perhaps even add some btu's on warmer days. Your thoughts?

Since this is a drainback system, I am looking to place a heat exchanger inside my hot water pressure tank. The cottage is off-grid so am trying to keep electrical energy usage to a minimum. Know of any in-tank heat exchangers? The tank is a large hi-efficiency 60 gallon gas unit with 2 - 1" NPT side ports for hydronic option. One of the 1" ports will have a 300 watt 12V screwplug heating element for diversion load. I am looking to fill the other with a heat exchanger. So far unable to source one and figuring on making one with some 3/8" soft copper tubing and a 1" hex head brass pipe plug.

All thoughts are very much appreciated.

Mark

[Dave Speer]

Hi Mark
I don't have any understanding regarding a unit full of refrigerant. My units can be filled with water or in my case food grade glycol for winter use. You indicate a drain/back system, that will work anytime however it eill require a closer eye on the system especially in winter. A drain back system would work well on a cottage and could be filled with water. The 4: stainless pipe I was refering to is a heat exchanger that works very well and cost very little. Your system would simply circulate water/glycol through the units and the heat exchanger. The other loop would be from the otherside of the heat exchanger tp the storage tank and then feed the regular hot water tank. This would maintain hot water with electricity when required and lessen the electricity requirements when the sun is gone also at the same time heating up a storage tank for later. My system if fully automatic and requires very little maintinence.
Cheers Dave

[Mark Parsons]

Hi Dave,

Thank you for the clarification and sketch. Ahhh.... the penny drops.:)

You are using your closed loop glycol system to feed into a custom made thermosyphon heat exchanger using the 4" SS pipe.

Do you think you need all 50' of copper pipe to transfer the heat in the exchanger? Did you execute any calculations to determine this length? What Delta T do you see?

I am trying to determine how much surface area will be required for my system heat exchanger.

Attached pdf describes refrigerant filled flat plate collectors briefly starting at end of page 22 into page 23.
http://www.alaskasun.org/pdf/SolarTechnologies.pdf

They don't work so well after 20 plus years of service. My collector now passes water through the absorber section originally charged with refrigerant. Seems to work very well. Limited testing so far shows about 1500+ btu per hour in direct sun. I also added some hi-tech duct insulation behind the original fiberglass. It is a foil/foam/foil product I bought from:
http://www.insulation4less.com/

Thanks for the guidance.

Mark

[Dave Speer]

Hi Mark
I havent used anything in building my water heater other than a little common sense. I don't understand most of the questions you have posted. I put fifty feet of copper pipe inside my heat exchanger because it fit. and It works. I started putting the thing together and then made modifications as I went along to prerfect the system. Now it works so I'm not going to fix it. This winter the system was making 100f degree water at minus 28c degree temperature with a windchill to minus 33c degrees. Living in the unorganized communities up here means that we don't have any services, I have to pump my water from Lake Superior and heat the line with Pyro. We have no public transportation so we have to use our car to go anywhere, this means our carbon footprint is quite high. My regular equal payment plan with Ontario Hydro was just under $300.00 and now even with the increase in hydro costs, my equal payment plan is $216.00. I am not suggesting anyone should use the system I built. But I am sure glad that I did and according to the calculations on the footprint that I did I have reduced my carbon footprint by 13.9%, I am pleased with that. I will continue to use my common sense to reduce the carbon footprint even more. This year I plan to make a self draining water line from Lake Superior that will not require Pyro heating which should reduce our carbon output even more.
I wish you every success with your project and most of all I hope you have much enjoyment in the construction I know I did on mine.
Regards
Dave