Solar heat collectors are a good supplemental heating source that can provide homeowners with free heat for their home when the sun is shining. Solar collectors are a box like structure that capture the energy from the sun and convert it into usable energy for heating purposes. Inside the collector solar energy is simply converted into usable thermal energy.
On the front side of the solar collectors . a clear panel or glazing material typically polycarbonate sheeting, single pane glass ,double pane glass face towards the sun and allow the sunlight into the collector box. On the inside of the collector box is a heat exchanger or a absorber. The heat exchanger or absorber is responsible for transferring the heat of the sun into a usable thermal heat source. The heat exchanger is suspended or attached inside the collector box and should be coated flat black with a high heat temperature resistant paint.
The flat black paint helps to absorb the heat energy from the sun. It is very important to utilize a flat finish black paint inside the collector box. If the paint has a reflective coating, it will reflect the sun back outside of the collector, which results in lost potential energy. It assists with the entrapment of that heat energy rather than reflecting it away from the collector.
Once the sunlight has penetrated the collector box through the glazing, the heat exchanger material and the flat black paint will absorb that heat and begin to warm the air inside the collector. As the air inside the collector and around the absorber warms, it will expand and rise. The expansion of warm air will naturally create a convection current. As the air inside the collector rises, it will continue to pick up heat through friction with the absorber. The air passing over and through the absorber is given more opportunity to gain heat by rubbing against that surface which is being heated by the sun.
Now that the air is warm and picking up heat and needs a way to move through the collector box, we install two vents on the backside of the solar collector facing towards the room or space that we want to heat. Through the vent at the top of the collector, the heated air moves into the home , the vent at the bottom allows the cooler air to return back to the the collector.
Having a return event at the bottom and a supplier event at the top of the solar collector allows natural convection process. The air inside the collector is picking up heat from the absorber and is naturally wanting to rise up and out of the collector. A natural force of air rising will induce a convection current, which will pull cooler return air from the room or condition space into the bottom of the collector box.
The collector creates a convection current inside the room .It removes cooler dense air from the bottom of the room and takes it through the collector where it is warm, and then exhausts the heated air out of the supply duct back into the room.
This project goes over the build of an entirely self contained Solar Air Heater using no grid power whatsoever. The unit draws the cold air from the room and exhausts hot air into the room using a 2 5V DC brushless 7 vane case fans. This fans are powered by a 16 Watt Amorphous solar panel. Both the intake and exhaust pipes ore of 5 inch diameter.
9 rows of 17 soda pop cans , a total of 153 355ml soda cans are used for the collector. The aluminum pop cans are painted with a flat black paint to ensure all sunlight is absorbed and not reflected. Also there is a five inch intake and exhaust manifold at the bottom and top of the unit. This ensures that all air travels through the interior of the aluminum cans.
To maximize the heat transfer from the sun to air within a given space, we need to build a better heat exchanger. Solar air heating systems use air as the working fluid for absorbing and transferring solar energy. Transferring heat from one place to another by definition is a heat exchanger. When the sun heats the metal, the hot metal heats the air circulating over the metal of the heat exchanger. The job is to capture radiation from the sun and transfer this thermal energy to air via conduction heat transfer. Heat transfer output depends on the rise in temperature and the airflow.
In order to minimize heat loss through the plexiglass , we keep the absorber temperature as low as usually possible. The cooler the absorber runs, the less heat will be lost out of the glass. A way to keep the absorber cooler while extracting the same amount of energy from the sun is to increase the airflow.
To improve conduction heat transfer without significantly reducing airflow , we disturb the airflow within the solar air tubes . Four holes are put in some of the soda cans to create a baffle that increase the turbulence .These baffle cans are placed evenly across the tubes to distribute the airflow. We place the first baffle cans on the second row from the bottom with the intention of disturbing the airflow early. The second baffle will be located in the 10th can .
In order to stack the empty cans, we make an assembly tray “V” shaped support structure using leftover baseboard. The cans are glued together using PL Premium construction adhesive that is water resistant, non shrinking and paintable. The soda cans are positioned on the loading tray and slowly rotated to evenly distribute the construction adhesive.
The “V” channel made from baseboards holds the cans perfectly straight.
The box for the Solar air heater is made of 5052 aluminum alloy sheets. The dimension of the box are 91 inches tall and 24 inches wide. We use a one inch flange and a metal bending brake to bend the aluminum to make the sides of the box. The top and bottom caps are bend to fit on the top and bottom of the box . When manufacturing the bottom caps, the distance between the bends is decreased by one millimeter to allow the caps to fit inside the solar air box to facilitate drainage.
Next step is securing the aluminum box top and bottom .The procedure involves using a smaller diameter drill bit as a pilot and then drilling to final size for the rivet only after the two pieces are mated together. The pieces being held together via cleco fasteners. The function of the cleco is to temporarily hold material in the exact position during the manufacturing process.
Two five inches holes are cut at both top and bottom on the box to install the plenums. The intake and the exhaust pipes for the two solar air heaters are manufactured from a single piece of five inch HVAC plenum. These are inserted and secured into the holes using construction adhesive.
The back of the box is insulated using two sheets of half inch foam sheet. One sheet of half inch foam is installed on the sides. A pneumatic air file is used to cut the sheets.
We install a snap action thermostat in the interior of the exhaust manifold, constantly monitoring the temperature of the air being brought into the dwelling. The intake and exhaust manifolds need to ensure that all air travel through the interior of the cans therefore it is important to have a good seal to each can. This also means that the manifold itself needs to seal well against the interior of the heat box.
Nine holes are cut on a two sheets of half inch plywood to make the intake and the exhaust manifolds. These manifolds are secured in place against the cans using PL construction adhesives.
The solar air tubes are held tight inside the box using two 1/16th half inch 6063 aluminum extrudes. These lightly applying pressure on the cans holding them firmly against the back of the heat chamber.
Three separate coats of high heat black rest-o-leum paint are applied to the box , all within 60 minutes of each other.
Clear silicon adhesive will be the primary method of adhering the Plexiglas to the solar air heater. After precisely positioning the glass on top of the heat chamber, I used a 1/8 inch pilot drill to go through the plexiglass. One full tube of silicone is used around the perimeter prior to laying the glass down.
We install 2 16 Watt Sailflo Duct Exhaust fans with a capacity of moving 141 CFM (Cubic Feet per Minute) for air . These are powered by a small solar panel. One blowing air into the chamber and one sucking air out. This helps to overcome the additional internal airflow resistance built into the design.
The completed solar air collector is installed outside facing south to maximize the exposure to the sun. Once the solar air collector is installed outside , we take the temperature rise between the incoming and outgoing air while moving 141 cubic feet of air per minute from the fans . The calculate the amount of heat transfer we multiply the CFM and Temperature rise with a factor of 1.08.
- How to heat your Garage by building a Super Insulated Radiant Floor Heating SystemThis project goes over the installation of a homemade radiant floor hydronic heating system for the garage. The radiant floor heating uses a pex tubing that is installed along the floor of your garage or room . Hot water is passed through the tubing which radiates the heat out into the room or space. The first step is to figure out what size pex coil tubing and how big of a water heater you would need . Also how many feet of tubing would allow enough heat to exchange into the concrete floor to sufficiently warm up the entire space. The total BTU/hour or heat required will be based on the square footage of your garage or room . We begin by levelling the ground and start laying down a vapor barrier .The vapor barrier is made out of 6 Mil Visqueen plastic PE film .The barrier keeps the moisture from under the ground to rise up to the surface of the floor. We then lay a mixture of sand and packing gravel before installing the two inch extruded insulating polystyrene foam on the floor and the perimeter. Four circuits of 800 ft half inch Pex tubing is stapled down on two inches of polystyrene insulating foam using a pex stapler. The eight tube ends are routed upto to a box from where it is connected to a manifold which is mounted on to the wall. The pex tubing with the supply and return tube is connected to the manifold with the help of a compression fitting . To check if all the connections are OK or if there is any hole or leak in the tubing, connect the manifold to a 100 PSOI air pressure gauge to do a pressure test. Five inches of concrete is then poured over the pex tubing circuits. Saw cuts of less than an inch are made into the concrete to allow for the shrinkage during the curing process. To insulate the pex tubing and to prevent water from entering into the floor, an expanding foam sealant is filled near the junction where the concrete meets the supply and return tubing near the manifold. The heating components of this system are mounted on a 4 X 4 square sheet of plywood. The heater has a rating of 7.2kW . The heater is flow activated which requires a circulating pump to pump water through it which then activates the heater based on the temperature setting. Two 120V fractional horsepower circulating pumps are used , one for running the water through the heater and the other circulates out through the pex loops. The pump has an inbuilt garden hose connector system used for draining. The hot water coming out of the output end of the heater passes through a pressure tank which removes the air bubble with an air release valve and prevents any water hammer to the system. This is further connected to the flow activated circulating pump for the heater with connections for filing and draining the system with the help of shut off valves. The water then comes down to a stainless steel manifold and then flows through the supply end of the pex tubing . The heated water splits into four supply loops at the manifold into the concrete floor. The water then returns back to the return end of the manifold through the other four loops of pex tubing and goes straight through another circulating pump and a Y strainer filter before circulating back to the heater. Two thermometers are connected at the supply and return end of the pipe to know the temperature difference of the outdoing water and the returning water. The flow is controlled by a thermostat and a switching relay that turns on the circulating pump . https://www.youtube.com/playlist?list=PLmHss3DBZUimsi9qV6RFJTUw6xh-P4B3Q
- DIY Video :How to build a Wood Stove that runs a generator, produces gasoline,runs a fridge and act as a water heater at the same timeThis is a wood powered gasifier stove that produces gasoline runs your generator, runs your propane hot water heater, heats hot water for you all off the grid. A simple design of a mini gasifying woodstove prototype here you've got some open latches, open up the door, the doors got the baton handle so it naturally stops on the downfall Inside the firebox, I've got a gasification style system built in there.One of the key things about a gasifying woodstove is that not only can I run it in a typical gasification wood stove manner, heat my home. But if I reverse that action with a fan and a draw system underneath the stove, with the ability to shut off the flow out the chimney pipe, and then draw down underneath the stove, reverse the action of the system, I can produce syn gas that can go outside and into a generator. This system has little latch up here at the top drops open so you can get in there work the material around.By actually pulling the little latch out and the bottom of the main gasifier inside of there to shut it and rotate it locks into place .It is actually a dump plate on the bottom of the main gasification chamber so that all the ash and all the coal that's not burned can dump out of the system into a tray below. A secondary burn system with two layers of stove pipe, one smaller inner diameter stove pipe and one larger one is made for a better burn to take place with fresh air inlets right there in the chamber. The outer sleeve stops below the bottom allows air to travel up in between rise up to the pipe.There is a set of burner holes that makes sure to mix fresh oxygen that creates a swirl in there and helps burn any leftover syn gas in the production system. So there's no smoke coming out of this in the end. Inside the woodstove is the inner chamber holds all your material, it gets hot and then creates an airdrop between this outer wall and the inner chamber wall that airdrop comes out these holes mixes fresh oxygen into the top of the system with the smoke and burns it. The bottom holes allow air to dry in from the bottom to complete that burn as the material burns down to the bottom. It also works slightly as a venturi system as air is drawn up these walls towards these holes, creates a vacuum down here at the bottom holes and pull some of the smoke out a downward draw into the system and pull some of it into here helping mix some of the smoke With the air and will swirl it so it'll burn cleanly. The single air inlet hole is used to pull the smoke out of the bottom to reverse this process to put syn gas out of this stove outside into a generator. There is inner set of holes in the bottom of the stove pipe.This helps mix air between the walls.The air gets drawn up between the wall since the inner pipe is longer than the outer pipe which mixes fresh air and completes the secondary burn to make sure there's no smoke coming out of this pipe. This is gonna be the bio crude oil production system here which is basically another term for a creosote that you produce from syn gas production, otherwise known as gasification production. It's got just a single pipe rolling out of the backside of it which is connected to a creosote collection container. As this gas starts to cool, it's going to come up to here it's going to work its way up hill, as it does so the hydrogen inside of the gas will be the lightest of all the gas is traveling uphill and definitely make it over the top much of the creosote we built re drip down into the second collection container here. Now the rest of its gonna go up cross through the pipe here and come down to a condenser The reactor shown here is made of two of five gallon steel cans.I cut the top off of one and the bottom off of another and slid them over each other. So they make a really long slide seal over each other one pipe, as you can tell here, welded in. With an elbow, it's a one inch pipe coming out of the back of they're welded in with an elbow. The downward slope of the pipe force the smoke to release as much of this crude as it possibly can. Because it's actually wanting to go uphill, which would be easy to smoke not going to cool real quickly. by forcing it slightly downhill, we're forcing a lot of that heat energy out, making sure it's releasing a lot of that, let's call it creosote or bio crude. It also allows for the creosote to roll down the bottom of the pipe into a container. The gas moves through a reduction point which reduces the pressure.The gas gets refined and reduced slightly in volume through the system. Hydrogen, carbon monoxide and all the rest of the lighter gases are going to easily flow up this pipe through thermodynamic pressure. Now you've cooled a lot of that gas by running it downhill, trying to bring in into this lower container as much the second grade creosote as you can, or biocrude. Now by running it up hill again, you can really force all the heavy hydrocarbons and other elements inside of this to focus out of the hydrogen gas and the carbon monoxide. This is a downhill pipe that's going to go anti the direction of natural thermodynamic processes that'll help condense out or precipitate out some of the oils at a much faster rate than it would be if that pipe was going the natural thermodynamic flow direction.The first catch is going to be the heaviest and thickness of the current Crude oil. It goes down that pipe from a reduction point here into the secondary catch.This comes up the hill here at the lighter gases not yet condensed, rises across loses a lot of energy and now is once again restricted into a quarter inch copper gas pipe into a 5 gallon water tank with a 20 loop condenser coil inside . The pipe out of that tank runs into a one gallon pickle jar. The next pipe comes out of the top of the jar, we're not actually trying to put it down too far because you don't want to bubble and once it starts to fill with crude oil, you just want to grab them the lightest of the gases, the hydrogens and the nitrogen, carbon monoxides and others that are still left within this system you want to grab, grab that right off the top. Now it comes up this pipe here goes through the T and once again we have a secondary condenser that this goes through now it's about four or five loops going through there, comes out through there. And that's where the liquids gonna condense from this condenser that's where it's going to be caught. The liquid will be flowing, dropping the jug and the lighter Smoke will continue on now down the pipe. The result of the bio crude oil project collecting 4 grades of oil.So the next step of this project now is to put this all through the refinery, which will actually be connected inside the woodstove that made all of this. So in the end, what we'll have is all the liquid being produced the crude oil once again, flow back to the woodstove go through the refinery out the refinery tower, and on the other side, we'll have a high grade fuel to use in any engine. https://www.youtube.com/watch?v=M1imlOX2pGI
- How to convert an Old Ceiling Fan Motor into a 70W Efficient Single Phase Alternator GeneratorThis project goes over the conversion of an old ceiling fan motor into an single phase alternator .You can't take your standard AC electric motor and spin it and get an electrical current out of it unless you modify it. The ceiling fan motor used here will produce about 70 volts at one amp which is roughly 70 watts. Through a bridge rectifier we can get about 70 watts of power out of it. We start by pulling the cover of the fan. Inside we have a squirrel cage rotor in the middle and 6 coil windings around it. The coil windings are placed in clockwise and anti-clock wise directions inside the stator. Next we remove the circular rotor from the threaded shaft which is attached to it with help of a vice. We attach the shaft with the rotor through it within a vice. With the help of an extra piece of pipe to give leverage, we press them against the rotor and push it away from the rod and pop it off. We are replacing the rotor that we have detached from the shaft with a two inch hex steel bar . It has six sides that matches with the six coils from the stator. With the help of one eighth inch drill bit we cut a hole in the center of our hex bar. We put the hex bar through the shaft and fit them snugly around the threaded area. We take six one half inch neodymium or rare earth magnets and place them along the the 6 sides of the hex bar. We place them in such a manner that the poles of the magnets are opposing each other. For permanent usage, wrap this with a little bit of tape or glue so that they are held in place securely. We place our modified rotor in the middle of the stator and align them such that they fit in tightly. The outer screen is bolted back onto the motor. We can also add second set of magnets to increase the magnetic field of the rotor .This will also bring it closer to the coils on the outside and increase the overall voltage. To convert the alternating current generated by our ceiling fan alternator to direct current, we use a bridge rectifier. It has 4 poles, 2 for connecting our alternating current, the other plus and negative for DC power. https://www.youtube.com/watch?v=k-4IbLOZwnA