Freon Solar Heating - I guess the correct term is
Solar Heat Pump
Ok, here is the plan, I got the solar panels completed but I have a better idea. I am going to build some panels and use Freon R12, or actually a replacement for R12. A good replacement that I will test with is %60 Propane + %40 Butane. Yes it is flammable, but there is all sorts of debates about this. Commercial coolant is also flammable and they still use it in buildings. You probably already have small tanks of propane kicking around your house, and don't you think it has the same dangers? Well, it works good in this mixture for a replacement for R12, and its not harmful to the atmosphere either. Its perfectly safe in a closed system. After all my tests I will then got with a mixture that is not flammable, just so I can say I did.
Here is a material data sheet for Propane(R290) - PDF file in Adobe Reader format
Another Masc. Link
I think the whole unit can be built from salvage and very little effort so I want to test this and see if it works. I think because of the temperature difference it would increase the efficiency of the solar panels. This system can be built from mostly scrap and even the panels will be easy. for the panels I intent on using the evaporators from the back of fridges, and pouring cement around them to build a flat panel. I think the cement will work great to store the power from the sun, and also to transfer into the Freon. Also the reason why I like this is because its CHEAP and easy to maintain.
I can always continue with the original plan of using the panels that I have rebuilt if it does not work.
It all starts here, this is an old air conditioner that was out of Freon and didn't work well anymore. I cut everything out of the housing it was originally in and tested to make sure the pump still worked.
From the diagram below, how could a hot water tank not work as part of an heat exchange, they already are! They have been built and pressure tested for your fresh water supply already. So off to the dump for my parts!
I found this unit in the dump. I felt bad about taking it apart because this thing was practically new. The burner looked like it had never been used, the whole tank was mint! I had pulled the top off this unit. Doing this makes me wonder something with the original design. the tank is insulated on the sides but the top has nothing. This would be the greatest heat loss in a tank, so for future reference, if you are going to add insulation to a tank, do something about the top!
The first thing to do here is to remove the water tank from the whole assembly. I used a saw to cut the metal away because the tank did not slide out. I figured later this was because I forgot to remove the gas control valve.
This is a nice tank! It would be good for any storage or pressure! You could probably even use it to pressure balance a water system. This is a cheap way to get a good tank for fresh water supplies, and possibly many other projects.
The first thing to modify on this tank for this project, is to make the chamber that the heat transfer will happen. The center of this tank is perfect, the part I am talking about is where the hot gasses usually run up the center from the bottom. What I did is to seal the bottom up and then tested for any leaks with water. Its hard to see from the below picture but you can get the idea.
What I am hoping will work here is to take some evaporators that I also removed from fridges in the dump and use them as part of the heat exchange. First of all I had to cut them up so I could stack them together to fit down the center of the water heater. I think they will work well because I have left all the little elements that I could on them.
Once they were cut, they fit perfectly into the center. They touch the sides a bit and its a snug fit. Height wise, they fit perfectly. They sit about 3 inches from the top of the tube, but enough to be totally submerged in fluid. I was able to fit all the coils into the center of the tank. I never had to cut the lines at all to make this fit. Plenty of room.
Researching what liquid would be used when I am ready, I have found that water has the best properties. Also needed in the water is some inhibitors and I have found Water Wetter and Dex-CoolŪ will be my best mix. I will use only %10 and leave the %90 water. Dex-CoolŪ may be bad for cars, but it will leave no residue at all, and will not form a thermal barrier. So Dex-CoolŪ actually has a practical use, who would of thought.
Next is to build my solar panels. I wanted to keep it simple and inexpensive. Here is the wood frame that will house it all. Notice the insulation in the right picture. This is a silver foil with air bubbles between two layers. They claim about R8 for this.
Placing the isolation into the panel. The below right is the elements placed into the wood frame. I had to also wire this down as it does not lay flat. just secure it to the back of the panel.
Zealand knows how to spread concrete so he stopped by and helped me. I am sure he has to think I am weird by now for all my adventures! Well, this panel has a rough finish, this is because I think that it will absorb more sunlight being rough.
Now to paint it. When Zealand and I first mixed the concrete we tried RIT Dye, but it really didn't make the concrete very dark at all. It helped a bit, but it is not black! So, here I am, painting with good old Tremclad flat black paint. Finished panel lower right. I will do some testing now with this the way it is. In the future I am going to put some glass on the front of this panel. In the sun it reached 140 degrees Fahrenheit. Now we will see how hot the compression side of the heat pump reaches for temperature, and how fast.
The heat pump somewhat assembled onto the tank lower left. Wow, I got lucky and I didn't notice until I was done putting this onto the tank, but the pump is actually R22, and using propane is an excellent match for this pump. I don't have to mix with butane at all, this is great.
