 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Solar : New solar project
Page 1 of 2   |
|||||
| Author | Message | ||||
readyakira Senior Member  Joined: 17/07/2008 Location: United StatesPosts: 114 |
So, I am starting another R/E project. I got my hands on a used solar collector to heat my water with. Currently my hot water is the only thing I have left on propane. Price of gas is $4.88usd last time tank was filled. With 5 people in the house I am using over $100 every 2.5 - 3.0 months. So, I have been collecting parts to let the sun assist me in keeping some monies in my pocket. So far I have managed to invest $0.00 on this other then time and gas. I have a collector with 10 vanes in it. I believe it is 4x10 or maybe 4x12. I pressure tested it to 65lbs last night and it held good. I have picked up a small pump that is used for moving the water to the tank from the panel. I have also picked up two thermostats, one that closes at 140f and one that closes at 38f. I need to pick up a pressure relief vavle, and I think i need to pick up some check vavles. I also have another hot water tank (electric one) to use as an extra storage tank if I can get enough hot water from the collector to warrant it's use. So the questions I have been searching for is just how should I plumb that panel in? I assume I have to "T" it into the existing in and out on the tank. I think it should be check vavled above these connections to prevent water circulating back to the well, and prevent water from being pulled from the house. Out from the tank to in on the collector, out from the collector to cold in on the tank? The electrical I can easily figure out. I will use one therm to turn the pump on when temp in the collector reaches 140f and one to turn it on when temps drop to 38 to prevent freezing in the collector. In florida that shouldn't happen but maybe 3-10hours a year in the winter. Any suggestions are greatly appreciated. I will try to post pics later. Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| RossW Guru  Joined: 25/02/2006 Location: AustraliaPosts: 495 |
If you're a bit handy, you could make one. Here's how I made my Low pressure relief valve |
||||
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
readyakira Not meaning ro rain on RossW's party, but a 3/4" T&P relief valve can be had for around $5 at almost any hardware store. You could even rob one off an old water heater. They are preset to pop open at 212*F or 150 psig. In most cases, they are a single-use device, so when it pops, replace it or it'll drip forever. If you're trying to isolate the solar panel from the house and or the well, a cheap in-line spring or gravity check valve should do the trick. If you're trying to isolate the panel from the receiver (storage tank) either elevate the storage tank and or throw in a couple of heat traps. That's nothing but a loop that discourages already-heated water from traveling against gravity. A check valve will suffice to isolate the panel as well if it comes out that the panel is above the receiver. I found using "Shark-Bite" fittings works like a champ. Unfortunately, they're a bit pricey, but I'm retired and don't care. Shark Bite fittings let you install and uninstall things fast without soldering, so for the professional "tinkerer" like all of us, they're just dandy. It appears you live on the Florida Gulf Coast. When I was in the military, I lived on a small island south of Fort Myers called Big Hickory Island and I had problems with freezing weather in late January and early February. I'm telling you that so you remember to put in a top and bottom drain valve. You must have a way to vacate all the water from your panel in an instant. If you don't have that option, you're sooner than later going to wind up with pipes split from freezing water trapped inside them. Hope this helps. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
I was thinking of that freezing thing. I have a thermostat that should turn a pump on at about 38f. That should prevent the water from freezing as it would circulate the water in the panel keeping it above freezing. But I do have a freeze valve that is supposed to open in the event the water starts to freeze. IDK how it works, but at least that is what the solar guy told me it was. Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
NathanM Newbie  Joined: 23/08/2011 Location: United StatesPosts: 5 |
Where in the US do you live? I live in the Midwest and would probably only be able to heat the water for about 6-months or less before it gets too cold. The other question I have is if you take showers in the morning, then wouldn't the solar heated water be cool by then? Need San Francisco electrician |
||||
| Guests Guest  Joined: 01/10/2003 Location: Posts: 52 |
Such a very amazing link! Thanks you for the post. |
||||
| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
readyakira Here's a link; I just did a solar heater project. I originally made it too small and have since enlarged it, but the basics of the build are there. I have the pump on a timer and a cut-in thermostat inside the collector panel on my roof set as you, at 140*F. The panel has to be hot before the pump is allowed to shove water through it. The timer is there so the system doesn't fool itself into thinking there's plenty of sunshine. If the water in the system was already hotter than 140* then the pump could come on and if it were then to get cloudy, I'd lose all the already-stored heat; that's why I put BOTH a timer as well as a thermostat on my rig. Seems to me I posted a build for the improvements around here somewhere too. If I run across that, I'll be back for an edit or another "update" on this post. Edit: Silly me. The improvements are on pages 2 through 4. Boy, gettin' old ain't for sissies! 
. . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
I'll have to get some pics of how the project is going posted. I finished most of the intial setup last night and by the time I left for work at 8am the pump was ciculating water! I cant wait to see how hot the water is when I get home! Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
[Quote=Readyakira]Don't you think Free/Renewable energy should be mandatory in new buildings? This is actually written in the UBC (Uniform Building Code) in my jurisdiction (southern California). All new houses are required to "stub out for solar". That means there are two home-run pipes originating at or near the domestic water heater and terminating on the roof. They must be insulated and carry a bundled group of signal wires from one end to the other to facilitate automatic pump switching. The problem is, government subsidies and tax incentives went away in the late 1970s and without that, nobody uses solar except people who can install it themselves. That would mean you'd almost have to be a plumber to have solar installed at any kind of areasonable price. I happen to be a licensed plumbing contractor, so i have solar on my roof. What's funny is if people would merely look down the road a bit, they'd see how spending a small pile of cash now would guarantee lower or perhaps as in my case, totally FREE hot water. I even use my solar-heated water in my space heating system using hydronics. Again, I'm a plumber and installed all this for only the cost of materials, but even at that, the solar portion cost me less than $400. Match that cost against a monthly water-heating cost and one can readily see the payback period is not even a year. Add in the cost of space heating offset by the solar and even if solar is used only as a pre-heater, it more than puts using solar over the top and in the rhelm of being a "no-brainer". What better deal than that is there these days? . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
@ NathanM In answer to your question about solar-heated water cooling off awaiting your using it in a shower, if a screaming-hot shower is what you want, if it were I, I'd adjust my schedule around when the system's water were the hotest. In general, if the hot water storage vessel is well insulated and ALL the piping in the entire solar system is insulated as well as there being in place both a glazed panel (to protect wind from diluting temperature) as well as a system in place, which prevents heat loss through thermal siphoning, heated water will last 8 hours without much heat loss. What really throws a screwdriver into the works is using hot water. When this is done, the driving force is the incoming COLD (ambient) water. If your stored water is just barely hot enough for a shower and you actually take one, it isn't long before the incoming cold water dilutes the temperature of the entire storage tank to the point of it feeling too cool for a comfortable shower. Water has a very high specific heat and it doesn't take much cold water enteting the system to spoil the party. A way around that is to use a hand-held shower and control the flow to the bare minimum at the onset of your shower. Do the soap, scrub, rinse thing, then you can bask in whatever hot water is left in the system. Doing it this way (we call it a navy shower) makes sure you don't wind up having to wash all the soap out of your hair with icewater! . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
So I have a 30 gal tank and a 50 gallon tank. cold water supply runs into the tank that is 30gal and used to heat water if needed. Hot to house runs out of this tank. From the boiler drain on this tank I have connected the pump and ran tubing to the collector input. From the collector heated water runs to the cold in on the 50gal (Storage tank). From the hot out the water goes to the pressure relief on the 30 gal. this forces hot water through both tanks effectively making both solar storage. The setup has been working for 48 hrs now and the water is OMG hot. A few things I Was wondering, the 50gal tank is computer controlled and as such should have a sensor in place of the normal thermostat. What would it take to design a circuit that will dump water to an auxiliary source for example a jacuzzi? I am thinking in the summer the water temps may get out of control if in winter season it is still scalding hot. I also would like to find a good source here in the states for a DC controlled pump. I have 60w of solar panels available and also have a two car batteries being charged by this. In the future I hope to add a DC controlled valve to dump the water into the jacuzzi thereby reducing the heating needed by the electric jacuzzi heater. Overfilling of the jacuzzi is not an issue by its design. I still have to wire in the freeze thermostat to circulate water if temps reach below 38f. Hopefully being we don't have extended periods of freezing temps, I will not lose all hot water and will not have to drain the collector on nights temps dip. I did design the plumbing to have the ability to shut of and drain both collector and storage 50gal tank separately if needed. I also in the future am thinking of dc valve controlling that as well. To bad I am not very microprocessor savvy. Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
@MacGyver: I think it should be mandatory to not only have it piped but at least a full simple install. It is not rocket science to install a basic system. And most houses are built by a builder here that hires plumbers etc to do the work. With the cost savings and you can also push it as environmentally friendly there is no arguable downside that I can see. At least not in the south like here in Florida where we don't get enough freezing weather to make the system have to be complicated. Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
I did not put any check valves in the system as I put a loop in the system that I believe will prevent thermo circulation from drawing the hot water up to the panel. Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
so, today is the first day I have been home to really pay attention to the solar project. Seems the water must all be over 140 as the pump has been running continuously for a while now. Beginning to wonder how much electric that pump uses. Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
readyakira Here's a Link showing the pump I use. The company that manufactures this puppy is located on the west coast of Florida, so maybe you're close enough to merely drive over and get it yourself, saving the shipping costs. For me, on the west coast of the entire country, the cost was $225.00 including shipping. I already have a similar pump and it has been in use on a daily basis for the past 35 years without a hitch. The pump is sealed and the "driver" screws on from the outside. It's magnetically coupled to the impeller and rides on stainless steel and Teflon bearings, so it should last forever. I'm very pleased with mine so far. The pump in the link was designed to be driven by solar or battery @ 12 volts d.c. A clever way to set things up is to let the pump be the "on" and "off" switch. When there's enough solar energy hitting both the collector and the PV panel, the pump circulates water and when clouds happen by, it turns off. Of course, that doesn't help you out when things freeze. I used to live in Ft. Myers Beach, FL right on the water, which usually insulates the surrounding area being a large heat sink, but we got several hard freezes in the 5 years I lived there, so don't be thinking you're immune from frozen pipes. As far as using your solar-heated water safely, there is a device called a "temporing valve" and it mixes cold water against the solar-heated water just before it enters your house. You set the temperature maximum of the house water before it gets inside, that way you don't wind up with scalded kids and grannies. Hope this helps you out some. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
http://www.radioshack.com/product/index.jsp?productId=123262 51 Anyone familiar with these? is this the kind of thing I can hook to a pc and program to turn some relays on and off using sensors? Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
readyakire I can't get the link to work; waaaa! . . . . . Mac  Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
http://www.radioshack.com/product/index.jsp?productId=123262 51 Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
for some reason it keeps putting a space between the 123262 and 52. there should be no space there. Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
readyakira Here's an Active Link. I've heard the term "Arduino" bandied about here on the 4m, but have no idea what it is. I"m sure someone else here will pop in and explain it. That's the beauty of posting something here. There's always someone who knows the answer. . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
||||
| Page 1 of 2 |
|||||
 Print this page |
