Converting electricity into heat is one of the most expensive uses of energy. If you’re not convinced, look at the power usage of electric appliances like microwaves, space heaters, water heaters, ovens, or coffee pots. The difference can be seen between your electric bill from a cold month, when you have to continually run your central heating, and during summer months, when the ambient temperature does not need to be heated.
If you live off-grid, you tend to be far more aware of what it takes to create electricity; you can literally watch your batteries’ voltage drop lower and lower when using an inefficient appliance. However, if you are tied into the grid, you should almost be extra vigilant as regards your power usage. Not only do you have to pay for it each month, but also the power plants that produce your electricity are rarely sustainable or environmentally conscious.
Being able to produce your own cheap heat in the winter can literally save you hundreds of dollars a month. If you are looking to be more self reliant then these 3 awesome projects are definitely for you.
How many people can say they produce their own heat and hot water for free. I don’t know anyone who does. I have a small pop can solar heater that warms my garage which in turn keeps my house warmer. I love it.
Well, luckily for you, these problems become a blessing in disguise because I have spent the last 40 years to put together the world’s most comprehensive collection of woodworking plans.What if I told you that you could get your hands on 16,000 woodworking projects with already “done-for-you” plans with step-by-step blueprints that let you build stunning, professional woodworking projects — easily, quickly & hassle free?
1.) How To Build Solar Hot Air Collector
Making a solar hot air collector out of free used 2 x 4 metal light fixtures, free old glass and free black paint to reduce our carbon body tape outline, reduce our untility bills and save money.
We are building and installing 14 of these hot air collectors on our south wall of our 140 year old house in Ontario, Canada. During sunny days in the winter these will completely heat our house for about 6 hours. After we make these, we will join them together venting the cold air from the bottom of the rooms and exhaust the top vents to the top of rooms. The fans will help increase the air flow to these rooms. The next collectors that we make will also be insulated and have a metal baffle inside to help concentrate the heat. The collectors then will be connected to the house and flexable dryer
duct inside the house will vent heat to various rooms . Check out our You tube home page for more info.
• Free Heat.
• No Fuel Needed.
• Cost effective.
Step 1: Dumpster Diving Time
Step 2: Prepare The Fixture Frame
Step 3: Painting the Frames
Step 4: Cutting the Vent Holes
Step 5: Intalling the Glass
Step 6: Solar Panel and Micro Fan (Optional)
Step 7: The Next Step
The Next Step
• Make more hot air collectors and mount them on the house to offset the heating bills. Possibly insulate the collector to reduce loss of heat through the side and back.
• Reduce the fossil fuels we use.
2.) DIY Solar Window Inserts
Free heat with minimal investment. Having a serious interest in renewable energy, I recently got the urge to try and create a solar insert that would simply slide into my existing window casings to help with the heating of my 1996 mobile. I saw on the local news one night how a local man built a solar thermo siphon (TAP) air panel to do just that using black aluminum window screen and plywood. OK, that’s fine if you don’t mind living in a cave as it totally blocked the view and incoming light through the window. The concept is fine and it works. He made a comment about how much he saved on heating, but I don’t remember what he said. Having seen many designs on the internet of solar space heaters using black window screen, I decided to test the idea last winter as I had a difficult time believing window screen could possibly generate much heat. So, I grabbed a couple of screens I just happen to have and attached them to the front door with magnets salvaged from a micro wave. Amazing!! I think I was getting over 120 deg. I didn’t write it down so I am relying on my (poor) memory.
Anyway, I wasn’t too keen on losing the view or light so I set my mind to wandering and came up with the idea of using poly film instead of plywood. The first prototype was made using poly film and the initial test gave me 90 – 94 deg. with the sunlight hitting about 60% of the window screen. Not bad. OK. Now, how can I improve this? If I can reflect the sunlight onto the backside of the screen, it should generate more heat. Aluminum foil? You would need a substrate to attach it to and it would also eliminate the view and light. Then it hit me! Aluminized Mylar (emergency blanket, rescue blanket etc.)!! I recalled that as I was playing with other solar projects that these blankets reflect light and heat yet are also semi transparent, so I tried it. Super! It is like having polarized windows and it boosted the output temperature about 4 deg. This winter will tell the tale.
What you need:
3/4″ square molding for basic framework
Black window screen – the window screen I see around here isn’t really black but Charcoal. Still dark enough to serve as solar absorber.
1/4″ X 3/4″ molding for attaching film to frame, screen bead molding?
Saw – table saw or miter box
Screwdriver or power driver
wood glue – optional
a sharp utility knife to trim excess film
heavy duty scissors or tin snips for cutting window screen – you might also consider gloves when working with aluminum screen
#6 X 1-1/2″ wood screws – I used 8 per frame
#6 X 3/4″ wood screws for attaching trim molding
countersinking drill bit for the above screws
Staple gun and staples – 1/4″ – 3/8″
POly drop cloth, emergency blanket or other transparent sheet to enclose air chamber and for anti siphon flap valve. Another option that may improve efficiency would be a thin polycarbonate sheet screwed to the frame.
Step 1: Build the frame
Measure your window opening and cut 3/4″ square molding accordingly. My windows are 29″ X 59″ so, two pieces 28-15/16″ for top and bottom frame, 2 pieces 57-7/16″ for side frames and two pieces 27-716″ for inlet/outlet frames. I cut the pieces for the main frame 1/16″ short for a slip fit into the window opening. A tight seal isn’t really necessary unless you have serious air infiltration around your windows. In that event, I would either properly seal the leaks or make another frame that you can seal tightly against the existing window and cover it with plexiglass/polycarbonate.
assemble the top and bottom rails to the ends of the upright rails using one #6 X 1-1/2″ wood screw at each joint. Here is where we might add wood glue for a more durable joint. Make sure your frame is relatively square and fits well into your opening. Not too tight and not too loose. A competent woodworker might dado the frames for a more professional look.
Now, add the inner rails that will create your inlet/outlet openings. Considering my window size and emergency blanket size (52″ X 84″) if I make the inner opening 50-1/2″ high, I can use the 52″ width of the blanket with minimal waste. That makes my vent openings 2-3/4″ high by the width of the frame. There is a formula for determining the vent size but me and formulas don’t get along too well. Some percentage of total collector area.
Now you might paint or stain your frame if desired.
Step 2: Cut and attach absorber screen
Now, lay your roll of black window screen over the frame, you may need a helper or a scrap of wood to hold down one end of the screen to prevent it from rolling back up as you’re trying to work with it. You are going to cover the entire side of the frame with two layers of screen. The first layer only needs a few staples to hold it in place. If your screen is larger than your frame, leave enough room between your staple and where you need to cut to allow you to get your scissors and hand in there to cut, then tack it down after cutting.
I found it easier to attach the screen and then cut slightly in from the edge so the screen is slightly smaller, about 1/4″, than the frame in all directions. You don’t want any frayed edges to stick out from your frame and catch or scratch your window frame.
Step 3: Attach screen to upper vent.
Since we’re working with the window screen, let’s flip our frame over and attach one layer of screen to what will be the upper outlet vent. This screen is necessary to prevent the flap valve from being sucked into the frame at night. This screen provides a seal for the flap valve so that at night when it’s cooling off, your warm air doesn’t get drawn into the solar collector and dumped out the bottom vent as cold air.
Just as warming air in the solar panel creates a convection current where warm rises out the top and draws cooler air in the bottom, the reverse is also true. Without some means of preventing reverse air flow through your panel, your warm air would be drawn into the top vent, cooled down, and dumped into your living space, thereby negating any benefits from solar gain collected during the day.
Step 4: Attach film to frame.
Step 5: Cut and attach molding.
If you are using purchased molding, now is the time to measure and cut it. We are only going to frame the inner opening with this molding, 52″ X 29″ in my case. So, three pieces 29″ long and two pieces 50-1/2″. The third 29″ piece will create the hinge for the upper flap valve, set this piece aside for now.
Starting at the bottom of the upper vent, place one short piece of molding over the film so it lines up with the bottom frame of the vent and attach with screws, nails or staples. Then we do the same with the bottom, aligning it with the top of the bottom vent. Next, we measure and trim the longer side pieces so that they just fit between the two end pieces, and fasten.
We’re almost done.
Step 6: Attaching upper flap valve.
Now, we need a piece of light weight plastic as wide as the frame and 1/2 – 1″ higher than the vent opening for the valve. We will trim any excess valve material upon completion. I used mylar here again because I had it and it is extremely light. Plastic trash can liner will also work. You need to have one good straight edge to but up against the trim molding edge. Carefully align the edge of the plastic with the edge of the molding at the bottom of the upper vent. When you are satisfied that there is not too much resistance to interfere with the flap opening and closing freely, staple the valve along the top edge only. Test the valve action again to make sure nothing got out of alignment. Satisfied? Good, now we can complete the project by adding the third piece of trim molding that we set aside in the last step to the top of the outlet vent. As with the last step, I drilled and screwed this piece to the frame.
If you picture a pet door in your door that swings in and out as your pet comes and goes, you can get the idea of what we’re doing here. The flap needs to swing to and fro easily, just like the pet door.
3.) How To Build Your Own Soda Can Solar Heater
While I have electricity out to the garage now, heat has been an issue all winter long. Mattar graciously lent me his kerosene heater, which did an okay job of taking the bite off the chill. Insulating the garage would go a long way to help keep the bitter Vermont cold out, but that’s a project for another day. I decided instead to take advantage of the south-facing side of the garage and build a solar furnace to collect some of that sunshine just bouncing straight off my garage. My dad built one years ago and said he recorded a 110-degree temperature differential between inlet and outlet. And I had enough scrap materials around the basement to do something similar to what my dad built.
I started with some 2x4s and plywood to build a simple box. I’m no carpenter, but I learned that if it’s wobbly, just add more nails.
I actually built the box to certain dimensions, based on what scrap materials I had and on the dimensions of my heat collection method – aluminum cans. That sure was a lot of Sprite. Fifty cans in five columns of 10 will funnel the air upward.
Sealed the box using adhesive caulk, just to keep any heated air from escaping the box.
So you may have already thought, “How can air climb the columns of cans when there’s no hole at the bottom of the can?” Answer: drill press and 3/4-inch bit. Times 45.
The last five cans, the bases of each column, will sit on the bottom of the box and thus will be unable to draw air from underneath, so I poked holes in the sides of each of the five.
Stack the cans with liberal doses of adhesive caulk. Give them enough time to dry.
Once they’re dry, I painted each column with black BBQ paint. Black to best absorb the sun’s heat, BBQ paint to keep from flaking off the cans. At the top, I drilled an outlet hole. I left an inch or two of space between the tops of the columns and the top of the box to permit air to flow out of the columns.
I drilled the outlet hole based on the diameter of some wet-dry vacuum hose I picked up, about 1-1/2 inches in diameter.
At the bottom, I used another wet-dry vacuum attachement that would more evenly disperse the incoming air. Screwed it in at each end, then caulked the seal.
Then started to caulk the columns in place. At the bottom, you can see the inlet hole I drilled. At about this point, I realized that a better place for the inlet would have been through the plywood at the bases of each column. In this location, the air can simply pass over the cans (there’s about 1/2 to 3/4 of an inch between the cans and the upper edge of the 2×4 frame) and not really pick up that much heat. If I were to relocate the inlet, it would force all the air to pass through the cans and pick up the absorbed heat. Next time.
The caulk is pretty strong. Kept the cans from falling out while I had the box inverted.
Also had some 3/4-inch PVC pipe from another previous project. Bought a couple elbows and T-fittings and whipped up a simple frame to keep the box off the ground and to angle it upward toward the sun. Didn’t give the exact angle too much thought.
Caulked a clear plexiglas cover on the front and sat the furnace out in the sun for a full day over the weekend to see how it would work.
Using some advanced technological equipment, such as this precisely calibrated pyrometer, I determined the intake air temperature, which should have been the same as the ambient air temperature, to be about 80 degrees.
Using the same equipment and methods, I determined the outlet temperature to be about 95 degrees – thus a 15 degree temperature differential. Not 110 degrees, but not bad , considering I didn’t even break $50 in materials – most of that being the plexiglas window.
Obviously don’t have the inlet and outlet attached to the garage – figures that the day I finish the furnace, it’s 80 degrees and sunny and it looks like we’re finally done with winter. Dad recommends wiring a pusher fan at the end of the inlet tube to keep the air circulating through the furnace.
Were I to do this again, I’d first make the furnace larger. As I recall, Dad’s measured something like four feet on each side. Obviously, the more surface area, the more heat you’ll pick up. Second, as mentioned above, I’d relocate the inlet to the back of the box to direct all the air through the cans. Or at least I’d cut a piece of aluminum to act as a baffle and prevent the air from rising straight up. Third, I might use those small soda cans I’ve seen in the grocery stores lately, just to get more surface area.
Are you ready to turn back the clocks to the 1800’s for up to three years? Our grandfathers and great-grandfathers were the last generation to practice the basic things that we call survival skills now… WATCH THIS VIDEO and you will find many interesting things!