Old hot water panels to refurbish.
 

Here is one panel that I have that I got from my cousin.

He has nine more. The panels need some TLC, but I was surprised at how warm it got just propped up in my garage on a sunny cold day!

YouTube - Solar hot water panel to refurbish

I am going to play around with what it takes to fix this panel up, and then decide what to do with the other ones he has. (They are frozen up against the outside of his garage right now...)

Are all the panels from your cousin that size? I thought they were bigger?

What were you thinking of using for glazing? I don't know how they'd fit, but I still have all those thermalpane windows laying around not doing anything...

Mother Earth News had an article on a family from Minnesota who made their own solar hot water system in an outbuilding and piped the water to their two story house to heat it with hydronic radiant floors. It showed how they built their own water storage tank using plywood, a pond liner to prevent leaks, a few fittings and some extruded polystyrene insulation. The tank held the solar heated water and they ran copper tubing into the lower part of their reservoir (using a fitting to go through the plywood and pond liner material) and made quite a few loops inside the tank and back out near the top of the tank). It was an inexpensive, but large capacity reservoir. They used 2x4's to frame the bottom and top of the tank to prevent the weight of the water from blowing the sides out. It might be worth considering if you are going to need a fairly substantial storage tank.

I belive that with ten solar water panels, you could likely heat your entire house with your only expense being to run a small circulation pump (after the system is set up). I'm sure your small PV setup could handle that small load.

Anyway, congratulations on the free SHW panel(s) and I'm looking forward to seeing how you use it/them.

You'd be talking about Gary (owner of builditsolar.com). Hes a member here and posts occasionally. Very knowledgeable and willing to share info. His solar shed is an amazing project. I've read it many times.

SolarShed

That's the one! I couldn't find it quickly enough, but that is the system that caused me to completely rethink the garage/workshop I am in the process of building. I've already poured the slab (with perimeter insulation as well as insulation beneath it) with my radiant heat manifold and PEX tubing. I plan to be comfy working in the garage with solar radiant floor and PV electricity.

Depending of the size of the space you want to heat, you might be in luck with 10 of those.

I'm kicking myself for giving away my three Novan collectors. I'll bet those could put
out 3,000 BTUh, even on a bad day..

In my house, I think a hot-water-to-forced-air would be the solution. (no ducts).

The panels I can get are not huge. They can be easily moved and installed by one person though.

I have a different panel, which I bought used, which is 4'x10' - that one will be used on my house for my solar hot water system.

I don't have fantastic solar access at my house, so it would be difficult to set up all these panels for heating my house. However, I might be able to mount a number of them on my detatched garage roof to help make the garage into heated space.

These panels have the glazing - it appears to be tempered low-iron glass. I have one of the "gaskets" - a rubber strip that goes around the outside edge of the glass and seals up the space between the glass and the aluminum frame.

I did have this solar panel just leaned up against the side of my garage. I had to chip away a lot of ice to get the gasket...

I went over to see Tim (Doax) today and brought the solar panel to refurbish.

In one day, we cleaned it up, soldered on new connections to replace the ones that were hacked off, and hooked it up with a pump and a barrel of water!

Here's what it looked like when we were done.
http://gallery.me.com/benhdvideoguy/...12674112210001

This was inside in an upstairs spare bedroom. That way we don't have to worry about the panel freezing, or climb around on a roof. The panel is basically mounted up against the inside of a window.

See all the photos we took of fixing this up at:
MobileMe Gallery

Nice job! When I first looked at the pics, one stood out instantly
http://gallery.me.com/benhdvideoguy/...C_3354/web.jpg

I said, they didn't have it in the hole! But then I saw the whole flat plate was movable. :)

When I installed my Novan collectors on the roof, I soldered on 3/4" screw on couplings.
looked like these..
http://image.made-in-china.com/2f0j0...n-Fittings.jpg

They connected the collectors to each other and to the up-down pipes.
And they made for a good leak-free install. It made taking them down easier too.

The hard part was using low-lead solder! :mad:

Yeah, the panels aren't the highest quality out there, but they will definitely get the job done, and of course the price is right! We just have to find a good way to refurbish the rest of the panels.

Ben, I was thinking about the panels a bit more last night. We were talking about using C channel for side pieces. We don't have to use one long piece. We could cut out right around where the header pipes stick out and replace just that small area with C channel or re-bent aluminum sheet. We would just screw the C channel to the sheet aluminum frame. This would allow us to use whatever end connections we want since we could drop the collector straight down.

I also just got done looking on www.mcmaster.com and they have a bunch of grommets we could use for plugging the holes where the pipes come out. Their pipe fittings are a bit cheaper than local ones too it seems.

The big issue we found working on this panel is that the frame of the panel is made from FOLDED ALUMINUM.

It's nice that it makes for a lightweight panel, and I am sure these were less expensive panels when originally purchased. The insides are all copper pipe and sheet copper absorber, so the important part is high-quality.

The problem with bent aluminum is that the sides are attached, as it's all one big sheet. If the sides of the panel were made from a separate piece, such as extruded aluminum rail, the sides could slide on OVER the pipes that have to stick out. Because of the folded frame, the original manufacturer made the copper pipes stick out on one side, and not the other. To connect the panels to each other or the intake and outtake pipes, you push a pipe INTO the inside of the panel and connect it with a rubber coupler by sticking a screwdriver through a hole in the frame to tighten a hose clamp.

Not an easy thing to do, and I am not sure I would trust it for 30 years in a closed-loop system.

After monkeying around for a while, we still couldn't figure out a really good way to solder on some pipe extensions that would still allow all the copper to fit back into the box. Our "compromise" of making this work was to more or less rebuild the rubber couplers with some short pieces of radiator hose and stainless hose clamps, install them with the copper OUTSIDE of the box, so we could really get our hands on those things and tighten them up.

The panel has two 1-inch header tubes, one on the top, and one on the bottom. Both tubes run horizontal, and are open on both ends. Typically, water (or antifreeze) would run in one end of the bottom, and the opposite bottom end would be capped off, so the water would rise up through the small tubes with the copper plate, soaking up the heat of the sun. The water comes into the top tube (which has the one end capped) and flows out the opposite end.

For a single panel system, the opposite two corners would be capped off. If you used the panel in series with an additional one or more panels, both the bottom tube and top tube would just connect straight to the next panel in the system. One of the tube ends would still be capped only on the first and last panel in the array.

We decided that this panel was only going to be used by itself, but in the future might be part of an array. If it was, it would be an end unit, so we could still permanently cap off one end.
To do that, we had to clean off black paint from one of the chopped ends so that we could solder it.
http://gallery.me.com/benhdvideoguy/...12674113880001
Then we installed and soldered a plain copper end cap.
http://gallery.me.com/benhdvideoguy/...12674115590001
I know the soldering isn't the greatest. We are both plumbing amatuers, but the soldering did get better as we continued.

On the kitty-corner from the capped end, this corner also needed to be capped, but possibly connected to another panel in the future. Rathe decide on the exact style of connector, we simply added a stub of pipe, and let it run long, so there is enough material that in the future it could be cut off with plenty of room to install whatever would be needed there.

http://gallery.me.com/benhdvideoguy/...12674115880001

Finally, we got to working on the ends the water would be coming and going through. There, we made new rubber couplers. We soldered up little adapters of a 1 inch to 1/2" reduced, a short piece of 1/2" pipe, and a pipe to threaded adapter. Then a brass thread to barb adapter screws into that. Finally, a high-temperature hose goes on the brass barb.

http://gallery.me.com/benhdvideoguy/...12674116110001

By that point, our soldering was starting to look slightly less hideous...
We also found that the radiator hose we used to make the coupler was almost exactly the right size to fill in the gap between the copper pipe and the aluminum frame.

On the output end of the panel, we made a similar adapter, this one with a male thread adapter, so it could go straight into a a brass tee. This way, we had a point for a temperature gauge to mount.

http://gallery.me.com/benhdvideoguy/...12674115370001

We gently washed off the collector manifold, and we were ready to reinstall the glass on the panel. The glass has a smooth side, and a side that is slightly textured, which I think is designed to diffuse the light? Does anyone know which side is supposed to be inside and why?

To mount the glass, we got some of those little plastic clips used to mount a mirror against the wall. In some holes they went right in. Other holes were too big, and the screw would just slip. I think the glass was originally installed with some sort of clip and self-tapping sheet metal screws.

The mirror clips show up pretty well in this photo.
http://gallery.me.com/benhdvideoguy/...12674116760001

We took the panel to the upstairs un-used bedroom. It has one window, which is just a little smaller than the panel. The idea was that we could simply mount the panel up against the window. The sun would shine on it, but it would still be in conditioned space where it couldn't freeze.

Here is the hose going to the panel inlet.
http://gallery.me.com/benhdvideoguy/...12674117700001
You can see that the pipe shifted just a bit. Originally, these panels had a grommet that went around between the pipe and the hole there. Four of those total held all the copper in place nicely. Our version, not as well.

The pump is a 12V DC stainless steel bilge/utility pump. Don't have to worry about it rusting and you can run it on a battery or a wall adapter. Tim didn't have a wall adapter, but he did have a old computer power supply, modified to be used for testing and running 12V and 5V electronics. At 12V, this pump pulls about 60 watts (5 amps) and really pumps faster than we need it to - something like four gallons per minute. Since DC motors run at a speed proportional to voltage, we hooked the pump up to the 5V power lead. The pump ran slower, but still running more than enough water through. At 5V, it only pulled 25 watts! So we were saving energy now too!
http://gallery.me.com/benhdvideoguy/...12674186360002

The bottom of the panel has a wimpy flange that sticks out. We were not about to set the full weight of the panel on that, so we added some 2x4 blocks to support the weight.
http://gallery.me.com/benhdvideoguy/...12674118500001

In this photo of the completed test system:
http://gallery.me.com/benhdvideoguy/...12674186530002
You can see:
Hose from the barrel to pump on the floor.
Computer power supply powering pump and connected to Kill-a-Watt for energy monitoring.
Hose from pump to bottom right panel water inlet.
Capped "stub" pipe on bottom left of panel.
Capped pipe on top right of panel.
Water outlet on top left of panel with temperature gauge.
Return hose from panel to barrel.

So, there you have it. In one day, rehabbing an old solar panel for only the cost of a few parts and one trip to the hardware store.

While this is NOT a permanent installation, the experience is well worth it, and we now know what we would have to do to fix up the rest of these panels.


NOTES:

There was one leak we found after filling the system. It was the inlet hose barb thread. The barb simply wasn't screwed in tight enough. Took a wrench and about 5 seconds to fix.

All of the solder joints were good. No Leaks! While our soldering was far from professional-looking, it did at least do the job! After having the panel vertical, and filled with water, I realized we had no way of checking a few of the solder joints or the rubber couplers for leaks. Perhaps the right way to do this in the future is to pressurize the manifold with it outside of the frame. That way, the whole thing can be inspected without the glass and sheet metal in the way.

The rubber couplers were covered with reflective metal tape, to prevent UV damage to the hose.

Any sort of complete circle still needs to fit around whatever size connectors we decide to use.

How about something like this?
http://gallery.me.com/benhdvideoguy/...12674577100001

Cut straight down, even with the two edges of the pipe hole. Two cuts of a tin-snips, that's it. Drop whatever pipe or connector we are using in there. Then cover it with a custom metal clip that holds the pipe in place. The clip can be held in with rivits or sheet metal screws. We could add a little caulk in there too.

That would let us use any sort of big coupler to go to the other panels, because they no longer have to fit through the hole. We can also eliminate all the rubber couplers, and use solid copper female-female couplers soldered in place. If we used couplers or disconnects to the other panels that were small enough to fit through the hole, we could just slide them through the one side, and then make two cuts and tabs on the other side to drop down there. Then we are only making half as many cuts and tabs.

Yeah, I was thinking something like that. I hadn't exactly figured it all out myself. But, it sounds way easier and cheaper than a full C channel side.

Here is a video which is an overview of how a Caleffi brand hot water system is installed.

At about 1:17 in, there are a couple shots of a brass coupler connecting one panel to another. Right after that, they show the spare end coupler being capped-off.

I think we want something similar to that for our refurbished panels.

Later in the video, it also shows filling the system with antifreeze. I think he goes through about 5 gallons total, for a two panel system with the panels on the roof, tank in the basement, and pretty large diameter hose connecting them (1"?)

Also, it looks like the flow rate was adjusted to pump 2.0 gallons per minute.

YouTube - Watch Bob "Hot Rod" Rohr Install a Caleffi Solar Thermal System

Wow - cool project!

So the barrel is just a test then?

No plans to plumb it to the kitchen for washing dishes or something? (Of course then it wouldn't be closed loop...)

That Hot Rod install was sweet! When they connected the two panels together in the center,
I saw the hardware was the very same stuff that I used on my Novan collectors.
The size and quality of those panels, looked very similar to my old system.

Makes me sad that we didn't keep it. But, it did pay for itself a few times over. :)

Glad you liked it.
I filmed that one! :D

Metro - this was only a test to see what it would take to fix up this panel, test the flow rate, etc.

We don't know what the rest of the panels may get used for. We might fix them all up and put some on Tim's porch roof and some on my garage. Something like that.

It would just be a crying shame for these to get recycled instead of back in service of creating free heat from the sun!!!

Hi Ben,

Got your PM, but couldn't reply to it, I don't have the 15 required posts. I tried to e-mail you, but since that requires 20 posts, it will take a bit longer. I don't want to post junk just to run the count up. As soon as I figure out how to describe the setup, I will gladly fill in the details.

Mark

Mark, its ok to run up your post count if you have useful info to share. We just use it as a way to identify and deter spammers.

Here is the video of the work we did fixing up the panel.

YouTube - Solar Panel Refurbish

I wonder how well those little mirror clips are going to hold your glass in place?

Perhaps a milling machine could be used to custom make some aluminum
hold-downs out of bar stock? Just mill a notch for the glass alone one edge
drill the screw holes and saw em off. :)

No mill handy, but we did talk about that!

I think the clips should work fine. The main issue was that we were re-using the holes in the collector frame, and some of those holes were a little slopped out. We still had plenty of clips in it.

I think for a final, mass-rehab of these panels, we would use some sort of milled strip.

Well, by the time I got home last night, the panel was already out of direct sunlight. It was a little warm so I did turn the pump on, but it only ran for a little bit and I'm sure it didn't do much. I'm a bit hesitant to just put the whole thing on a timer to run during the day as we've never had the whole setup up to temperature yet... A leak would be very bad news!

If we cut that little notch in the frame of the panel, we would be able to have the entire guts of the panel out - check all the soldering joints, and pressure test it. After that, we would put the whole thing back in the frame, stick those custom clips on, add the glass, and mount up the panel.

That would make me feel a whole lot more confident about our soldering!

The Bleeding air!
 

http://www.high-performance-hvac.com...c_air_vent.jpg

When installing my system, I didn't feel the need to install a big float type bleeder.
(The bleeder goes on the roof at the highest point in the plumbing, where an air pocket might form).

Instead I used the cheap and durable type.. That might last forever.
Instead of a few years. A unit that was easy to cover with installation.
http://images.meredith.com/diy/image...SCP_237_08.jpg


After the glycol fill, I used a 2-way to tell my wife in the basement to turn on the pump,
while I was on the roof using a screw driver to bleed the air out.
After a while, the air was all gone and the pressure was good.
After a few years, I climbed up and just cracked the screw a tad and got no hiss, but pure glycol mix..

I was glad that I didn't use the float type. I changed about 4 of those on my
boiler, before installing a manual bleeder with a copper hose.
(Ice maker kit screwed right in). :cool:

It's Saturday! Time to be at home instead of at work all week, away from the Solar Panel.

Tim just told me that he is running the circulating pump on the panel right now. It's sunny and about 37 degrees F. outside.

We'll check the temperature gauge on it later today and see how much heat we can make with this free panel!

I know Ben has been waiting for this all day, so here goes. :)

As he mentioned, I plugged it in early this morning as soon as the sun started hitting it. Something to note, I keep my house at 60F during the night and 69 during the day. So, some of the initial heating probably came from the house as well as the panel. But, to keep this all pretty short, I made up a nice graph.

http://ecorenovator.org/pictures/paneltest.jpg


Anyway, the panel didn't heat up the tank nearly as much as I had hoped. But, I did get a good look at it when I did the measurements around noon time. Having it in the window really limits the amount of sunlight hitting the panel. I'd estimate at best, only 1/2 to 2/3rds of the panel is being hit by direct sunlight. This is a severe limitation. Also, I noticed that the mirror hangers are not sealing the glass to the case, so I'm sure there is a fair amount of heat loss there.

As Ben mentioned, it was quite sunny today, as good as can be expected for this time of year IMO. Once we get one of these in the open getting full sun and sealing up the glass I'm sure we'll see much better performance.


Raw data:
http://ecorenovator.org/pictures/paneltest2.jpg

Well, I WAS hoping to see higher temperatures than that as well.

I did a test last summer in my back yard, using the same barrel and pump (pump was at 12V flow rate, I had to cycle it on and off manually) but a larger panel.

That panel was 40 square feet, so basically double what's in Tim's window.
The 40ft panel heated up water rather quickly. I suppose that we should expect a panel half as big, getting half as much sunlight, to only make one quarter as much heat!

I did just check the tank temperature this morning at about 8:00 and it was still 69F. Not bad for sitting overnight in a 60F room.

Of course, yesterday was completely sunny and wonderful out and today its all foggy and nasty. Why? Because I got an outlet timer to run the panel off of. Today it'll start at about 8:30am and shut off around 3:30. These are about the times where the sun starts to and stops hitting the panel.

Timer? What you need is the real-deal!

http://i46.photobucket.com/albums/f1...r/NCL/F015.jpg

http://i46.photobucket.com/albums/f1...r/NCL/F017.jpg


Comes with OEM Mounting bracket and AC line RF filter, included at no charge!!

http://i46.photobucket.com/albums/f1...r/NCL/F014.jpg

Otherwise, it's just going to end up on Ebay with all my old Ham gear.. :eek:

Haha, yeah I know. This was just a quick $6 fix to get it running during the day.