Cardboard Passive Solar House

This is a cardboard passive solar house. This house uses solar panels and a battery to power two fans and LEDs. We will also incorporate aspects of a passive house in our design so we need less energy to change the temperature inside.

Materials: Cardboard, hot glue sticks, solder, masking tape

Tools: 1 box cutter, 1 hot glue gun, 1 ruler, 1 wire stripper/cutter, 1 soldering iron, 1 digital multimeter, 1 pair of safety goggles

Supply: 2 Solar panels (12 volt, 70mAmp), 1 solar panel (12 volt, 40mAmp), 4 alligator clips, 1 USB cable switches, 1 power bank/battery

Load: 5’ of 16 gauge wire, 1 USB cable switch, 4 euro splicing blocks, 2 switches, 2 fans, 1 resistor (220 ohms), 3 LED lights (I used white, but you can use any color you want).

You may also want paper and a pencil to create a blueprint for your solar house.

Supplies: Paper, pencil

Draw up a floor plan for your house. Determine which rooms may need more sunlight, such as your living room, and which may need less sunlight, such as a closet, and arrange your rooms accordingly. Be detailed - include measurements in your blueprint.

Consider the latitude of your location and the solar altitude when determining your maximum panel tilt. Your panels should be facing south if you're in the northern hemisphere and north if you're in the southern hemisphere.

Decide where to put windows for best air circulation and lighting. South-facing windows are ideal because they are cheap and add constant heat and natural light to the house during the day. North-facing windows, however, lose a lot of heat and get very little useful sunlight in the winter. Try to minimize your north-facing windows. Some ventilation options for you to consider are:

-Cross ventilation; one window on either side of the house. One should be lower so cool air can enter and the other should be higher so the warm air can flow out.

-Single-sided ventilation; one window on one side of the house. Cool air will flow in the bottom of the window, absorb heat as it circulates around the room, and flow out the top of the window. Less effective than cross ventilation

-Stack ventilation; at least one window in the wall and at least one window in the ceilings or high on the walls. Cool air will enter through the lower windows and exit through the higher windows.

Lastly, add some overhangs to your design. Overhangs are edges of roofs that extend beyond the walls and block windows and doors from rain and sunlight. They can even reflect sunlight into the house to heat it up. Your overhang should be the right length and angle to block the window from the sun for most hours during the day.

Supplies: Ruler, cardboard, box cutter, masking tape, hot glue gun, hot glue sticks

Measure and cut your cardboard to fit the dimensions of your blueprints. Hot glue your walls and floor together. It may help to tape the cardboard together before you begin hot gluing so you can be sure you like your design. At this point, you can add any cardboard amenities you want, such as a couch or a table. I recommend not gluing your roof on yet so it is easier to add in your loads and circuit later.

Supplies: Solder, 1 ruler, 1 wire stripper/cutter, 1 soldering iron, 3 LED lightbulbs, ≈17" of 16 gauge wire, 1 resistor (220 ohms), safety goggles

Using the wire cutters, cut one 9-inch length of wire and two 4-inch lengths of the wire.

Strip the ends of the wires:

9-inch wire - strip 1/2 inch off one side and 3 inches off the other side. Twist the exposed wire on both ends and solder the tip of the 3 inches of exposed wire so it doesn't fray.

4-inch wire (#1) - strip 1/2 inch off one side and 3 inches off the other side. Twist the exposed wire on both ends and solder the tip of the 3 inches of exposed wire so it doesn't fray.

4-inch wire (#2) - strip 1/2 inch off both sides. Twist the exposed wire.

Bend the legs of the LED and place them on the exposed wire. Make sure the positive legs are all on one side and the negative legs are all on the other. Test the circuit with a battery to ensure that your legs are all placed correctly.

Solder the legs of the LEDs to the exposed wire.

Solder your resistor to the end of the shorter wire. Solder the other end of the resistor to one end of the extra 4-inch wire. Add heat shrink to the exposed wire around the resistor.

**Make sure to wear safety goggles when you are soldering. I also recommend watching videos and doing research to familiarize yourself with the soldering iron.

Supplies: Solder, 1 wire stripper/cutter, 1 soldering iron, 1 digital multimeter, 2 Solar panels (12 volt, 70mAmp), 1 solar panel (12 volt, 40mAmp), 4 alligator clips,1 USB cable switches, 1 power bank/battery, safety goggles

Cut one end off of the USB cable switch off. Separate the two wires inside and strip about 1/2 inch off the end. Twist the exposed wire so it doesn't fray. You can even put a little pit of solder at the end of the wire to hold the wires together.

Using alligator clips, connect your solar panels to the USB cable switch in parallel. Your switch should then plug into the charging port of the portable battery.

At this point, you can use the digital multimeter to test that the current is flowing correctly.

**Make sure to wear safety goggles when you are soldering.

Supplies: Solder, 1 wire stripper/cutter, 1 soldering iron, 1 USB cable switch, 4 euro splicing blocks, 2 switches, 2 fans, the LED circuit we set up earlier, safety goggles

Cut one end off of the USB cable switch off. Separate the two wires inside and strip about 1/2 inch off the end. Twist the exposed wire so it doesn't fray. You can even put a little pit of solder at the end of the wire to hold the wires together.

Put one wire from the USB cable switch into each hole on one side of the eurosplicer. On the other side of the eurosplicer, insert the wires from the LED lighbulb. Add in a switch to that circuit so you can control when the LEDs turn on and off individually. Lastly, set up the two fans and the last switch in series and put the wires in the same holes as you placed the LEDs.

Connect the USB cable switch to the portable battery. Make sure all of your switches are turned on. If your loads don't start working at this point, it may be because you connected the negative wire from the switch to the positive wire from the load. Experiment by switching the wires of your load until they work.

**Make sure to wear safety goggles when you are soldering.

Supplies: Masking tape, hot glue, hot glue gun

Determine which rooms you want the loads in. Once you have done this, install them to the ceiling with tape. Once you have your loads where you want them, you can glue down the roof.

Attach the solar panels to your roof. I used cardboard to create a shelf for my solar panels to rest on.

I recommend putting the wiring and the power bank on the side of the house. You can use more cardboard to hide the messiness of all the wires. Make sure all your switches are easy to access.

Enjoy your house!