Hybrid Solar Air / Water heater collector done

[CmeBREW]

Hi Guys,

    Here is my 96SF Air (and some water) heater which I had said I would show awhile back:

Here is the link.  'GaryGary' was good enough to let me put it on his site under the 'Active Solar heaters' section.  It is mainly an AIR SPACE HEATER though, made with a wood frame. (The Small water heating system is extra)

http://builditsolar.com/Projects/SpaceHeating/SolAirColWithDHW/AlAirCol.htm

It also heats some water in a 55 gallon plastic drum in my bedroom closet to get some more BTU's at night time. (Bedroom only)

It does work fairly good for the small size. Of course the water heating is very small scale compared to what it should be normally, but it is all the room I had to spare!

It heats the water using PEX tubing with aluminum wrapped around it. (could've been done better though)

It has been a very interesting project to do -- and I learned a LOT.

There's more photos and explainations at the link.  

Even though I am certainly no expert on complex Solar matters, I would be glad to try to answer any questions from my basic observances and knowledge.(I have a book)

Any suggestions or comments welcome. I obviously could have done some things better. Many of you know WAY more than me!

Thanks.

[zap]

Very nice Al and as Gary pointed out, it's not bad looking.  It looks like a big sliding door opening and I love how you got the return air ports to look almost like a piece of furniture.

Are the notches in the vertical 2x4s in case you wanted to add more PEX?

In the full pictures from the outside it looks like there is still siding behind the polycarbonate ... horizontal lines.  Maybe I missed that on Gary's site?

Nice work and thanks for sharing.

[Ungrounded Lightning Rod]

I take it the white stuff in front of it is a "doubler" (though significantly less than doubling the input) to bounce up and collect some of the light that hits the ground.

I recommend black pellet-stove touch-up paint.  Comes in a spray can.  Stands the heat and doesn't stink once cured.  (At least the stuff our pellet stove guys used works that way.)

Using the CPU water-cooling pump for low-flow, long-term, low-power, 12V heat-transfer-fluid pumping is a great idea.

As long as you're forcing the air why not have it exit at ground level for better mixing.  (Of course with the exit up it will run by convection somewhat even if the power fails.)

[CmeBREW]

Thanks Zap,

"Are the notches in the vertical 2x4s in case you wanted to add more PEX?"

  No, actually all the many notches I had to cutout are for the Metal Roofing 'corrugations' about every 6".  Yes, that was somewhat of a pain to do, but I had to do it for a tight fit of the Metal roofing to the vertical 2x4's so the air flow would go up and down the sections correctly.

If I would've had the Metal roofing flipped over the other direction, I would not have needed to jig-saw out those many notches, but it may not have looked as good in appearance.

I used a lot of Silicone there also. I think I would now rather use self-adhesive 'Weather stripping' to seal the vertical 2x4 runners instead of Silicone.  I think I would also use Weather stripping on the 2x6 top and bottom 'wiggle strip' cut-outs also, but with a big bead of Silicon right under the weather stripping for extra good seal.

Even though that looks like siding, it is just typical metal roofing painted with flat black stove paint.  I would be afraid of toxic fumes coming off Vinyl siding myself at 150F. (Not sure though--could be wrong??)  

[CmeBREW]

Thanks ULR,

     Yes, I like the white Limestone. It seems to add around 10 percent more to the collector heating. I did notice a difference.  I also thought it would look good and I didn't want to ever mow grass around this, so I put a piece of black 6mil plastic down and put the Ton of 4" thick Limestone over it.  It is very white when dry and only cost $20 bucks for the whole Ton at the local gravel querry.

Yes, I used the flat black high-temp stove paint for the front of the Absorber shown.  The odor with that went away fairly quickly.  I suspect it was the exterior Latex paint I painted all the insides with (2 coats), and possibly also the 4 whole tubes of 100% Silicone I used, is what took longer to burn off the fumes.

The CPU pump has been working fine.  Also, the auto-drain works perfectly. It has already been well under freezing (18F) numerous times, and it drains completely. I can tell, because it takes about 12 seconds after I turn the pump on to fill up the whole Pex line(s) and for the water to come back to the tank.  Fist, I can hear the air blowing out the line in about 10 seconds, and then the 'initial' hot water comes out the Pex tubing back into the tank.  

Yes, that is why I put the exit ports (and fans) up at the top of the walls. Without any electric with the fans off, the system still works about HALF as good with simple convection.  It is neat.    

[Junkie]

Looks very professional. I hope someday I can have something similar! Using the white stone is great idea.

[dnix71]

Is the water pump run from the solar panels so it pumps when the sun is up, or do you have a thermostat or do it manually?

[CmeBREW]

Thanks Dnix71, good question--

Actually, No.  

The CPU is electronic and HAS to have a 12v regulated power source. So hooking directly to solar panels would be bad.  The fans also have transistors and therefore 'Wild Voltage' (like from direct solar panels) will blow them up.

So I use two different regulated 12vdc sources.

My 12v Batteries (automatically regulated and steady) when I can.

AND if I have no extra RE-power that day, I just use a nice 12vdc regulated 'switching type' power supply (40watt max) I got from the www.Surpluscenter.com catalog. (back cover/ only $7 plus $1 for cord)

Even though this pump is small, it still has a power surge, so the power source needs to be at least capable of 35Watts.  A wimpy little 12v transformer will not do--it would ruin the pump in no time.  I also got the two 12v Fans from Surpluscenter when I got the power supply.

The thermostat automatically controls ONLY the two fans -- on normal sunny days. I have a bypass (typical 120vac) wall switch that turns the fans on manually, bypassing the thermostat. I have to use the bypass switch on those many 'Bright gloomy' type days when the thermostat cannot reach 70F and turn on automatically. The system works for me fine. Also,  I simply turn on/off the water pump with a normal wall switch.

Thanks for question.

[SparWeb]

Well done and I agree it looks really nice!

I wonder why you ran the corrugations of the steel horizontally - not vertically.  Could you not get any corrugated close-out strips to seal the ends like you can for the SunTuf?

I need to put one of those on my garage - I already want to give it some solar electric panels, so why not solar heat, too?  :-)

[MattM]

What prevents the growth of Legionellosis (Legionnaires' disease) in the water?  90-95ºF is optimal for its growth.  It spreads through the air.  Any muscle aches?  Coughs?  Feeling a little bit under the weather like a slight case of the flu?  If you could get that water temperature to 150ºF it would make me feel a lot more comfortable with this project.

My secondary concern would be how well that barrel holds up to 150ºF water.  Perhaps you could wrap it in strips and insulation like the project you did for your parents?

[CmeBREW]

Thanks SparWeb,

     I just happen to have access to the 12ft long pieces- so I used them horizontally.  Vertical would look neat too, maybe better since it would sorta look like 'Black blinds' in a big set of sliding doors.

I wanted to save some $$$ is why I didn't go with the normal foam 'wiggle strips'. I don't even really know how much they cost as there was none available at Lowes.  Probably order them from Lowes if one wanted to use them??

I'm sure one of these would work great for a garage. Would be really easy if it already had metal siding/roofing!  I wish so much we had used Metal (dark green, brown or red) roofing for my house and my dad's house when we made them a few years back instead of the good'ol fashioned Asphalt shingles!

Talk about easy to just put the polycarb panels (whatever length one needs) over the colored metal roofing with this same basic principle and pull the massive heat off with big air fans. (probably from ABOVE the metal would be way cheaper)

  Or, possibly rivot copper piping to the underside with aluminum for an awesome water heating system?? Wish I had the mula to do something like that for my parents house! Right now he burns a TON (actually more) of fire wood for heating.  When that wonderful resource runs out, he is in big trouble.

-Thanks.  

[CmeBREW]

Thanks MattM,

     I never even heard of this Bacterial Disease before. Thanks for bringing this to my attention. I had failed to mention that I always put a few tablespoons of chlorine bleach in the water to hopefully prevent Bacterial growth.  I think now I will add more and change the water in the tank one a year.

I will keep reading on this so as to be certain things are safe.

I will also seal the hoses that go into the tank to prevent any vapor from escaping.

I see now why it is best to take the water up past 140F. That will be difficult though.

I wonder what others do with their Solar water heating tank system? I would think the water in those big tanks goes below 140F from time to time??

Your comments at the beginning made my laugh, because I have the Pig Flu right now -- and yes I have all those symtoms you mentioned.  But I caught it from my dad a few days ago. Its like a bad cold. But I still have my appetite thank goodness.

[MattM]

Circulating the water and high heat are your low tech ways to kill it. Chlorine has to reach annoying levels of smell to be effective. The smell is the evaporation of the very poison that kills the bug; constant replenishment is necessary. Copper-based poisons and ultrasound are the new high tech ways to treat your water.

Don't be too quick to blame pig flu.  Make sure you let the doctor know about the possible exposure.

[ghurd]

Looking Great Brew!

Not sure if I mentioned this idea before.

AL tubing?  I have seen it rolls a few times really cheap.  For AC or something.

Could "weld" it with a propane torch and some of those "AL welding rods" (they work well, but it is not really welding).

G-

[CmeBREW]

Thanks Ghurd!

    That sounds like an interesting idea--something to look in to-- and cheaper than copper.  

This is the main reason I showed this project of mine (or ANY project) -- so hopefully it might give others ideas on how to make their's even better and HOTTER.

I realize now that copper or aluminum tubing would have been much better and hotter in the restricted area of the top of the collector, especially if the metal tubing is actually FASTENED (rivoted) to the Hot Steel roofing instead of having it just in mid-air like I did. . It is clear to me now that the steel is hotter than the air flowing behind the steel.

I just noticed yesterday that in the photograph of the collector, that I could have actually rivoted about 10 (10ft long) copper/or aluminum pipes in the horizonal metal roofing 'grooves' with aluminum sheet and it would have done WAY better at heating the water up and over 140F.  And Don't have to be angled for draining like PEX, and could be soldered in a square pattern with the 'grooves' and still drain fine.    

Perhaps I'll change that next year when I can.

P.S.  Thanks Ghurd for your great help with the Electronic Relay circuit!!(again)

I forgot to mention it in the posting.

[MattM]

Any updates on this project?

[MattM]

Any new updates on this project?