In this article, we will guide you through the process of building a portable, battery-powered air conditioner for off-grid use. This DIY project uses a cooler, a radiator, a pond pump, and other readily available materials to provide up to 10 hours of cool air using bags of ice.

 

 

STEP 1 : The Materials Required

• Cooler: A large, well-insulated cooler (e.g., Coleman Xtreme)

• Radiator: An automotive transmission oil cooler

• Fan: 18-volt battery-powered fan (e.g., Ryobi hybrid fan)

• Pond Pump: USB-powered pond pump with an open intake

• PVC Pipe: 4-inch diameter PVC pipe and a long sweep elbow fitting

• Toilet Flange: 4-inch diameter to fit inside the PVC pipe

• Insulating Foam Board: 1.5-inch thick, cut to fit inside the cooler

• Aluminum Angle: Lengths to create a stand for the radiator

• Zip Screws: To secure the aluminum angle stand

• Wood: Small piece of scrap wood to elevate the radiator

• Silicone Sealant: To create a watertight seal

• Hot Glue: To temporarily secure components during testing

• USB Power Bank: To power the pond pump

• Batteries: Compatible with your chosen fan

• Salt: Rock salt or table salt (optional)

STEP 2 : Prepare the Cooler 

Center the toilet flange on the cooler lid, ensuring it’s away from any hinges or latches. Mark the circle for cutting.

 

Drill several pilot holes around the marked circle.Use the jigsaw to carefully cut out the circle, creating the opening for the PVC pipe

 

 Repeat the marking, drilling, and cutting process for the fan opening on the opposite side of the lid.

STEP 3 : Setting Up the Radiator

 Measure the interior dimensions of the cooler to determine the necessary length of the aluminum angle. Cut the angle pieces to create a rectangular stand that will elevate the radiator above the bottom of the cooler.Assemble the stand inside the cooler using zip screws. Ensure the stand is sturdy and leveled

Take the aluminum pieces used for securing the radiator and screw them into the sidewalls of the cooler using zip screws and silicone. This will create a permanent mounting for the foam insulation, allowing for easy removal and filling with ice. The silicone will ensure a watertight seal and prevent any potential leaks or mold issues.

 

STEP 4 : Create the Insulated Chamber

Using the radiator packaging as a template, cut a piece of foam board to fit snugly around the cooler body.

Ensure the foam board creates a separate chamber for the ice, leaving space for the radiator and pump. You can add additional foam pieces on the sides for extra insulation.By cutting the foam in half, it can be easily removed from one side of the cooler, allowing for easy access to the ice compartment. This makes it simpler to fill the cooler with ice and reassemble the system when needed.

HVAC tape to cover the exposed edges of the foam insulation. This is done to prevent any styrofoam particles from entering the pump and potentially clogging it.

Place the radiator on one side of the cooler and attach the inlet and the outlet tubes to the sidewalls of the cooler using the HVAC tape. 

STEP 5 : Test the System

Add a gallon of water and three bags of ice to the insulated chamber, ensuring the pump intake is submerged. Connect the pond pump to the USB power bank and turn it on. Verify that water is circulating through the radiator and back into the cooler. Turn on the fan and observe the airflow and temperature of the air exiting the outlet pipe.

STEP 6 : Final Assembly and Use

Securely attach the fan to the lid and the outlet pipe to the toilet flange.Fill the insulated chamber with ice and water, ensuring the pump intake is submerged. Add salt to the ice water for faster cooling.Connect the pond pump to the USB power bank, and connect the fan to its battery source.

Image Credits: Make Everything