A walk-in cooler is useful if you need more refrigeration space for perishable foods. Purchasing a walk-in unit or having one built in your home can be extremely costly; you can often save time and money by building one yourself. It will require specific tools and parts from your local hardware store and a basic knowledge of your electrical system, but with some time and effort, you can have a custom-made walk-in cooler in your home for a reasonable price.
Choose a place in your home that is spacious and located within appropriate proximity to an electrical breaker box. Your walk-in cooler should have its own breaker because it will use a great deal of electricity.
Build your frame out of your 2x4 wooden planks, remembering to measure a space for your wooden door and your air conditioning unit. The 2x4 planks should have two inches of space between them. For an 8x8x8 cooler, you will need at least 16 2x4 planks. Follow the same procedure for your ceiling frame. Use 1/4-inch particle board as the base for your flooring. You will need roughly 64 square feet of particle board to cover the entire floor area. When your frame is complete, install the door.
Run your electrical wire to a plug above the space you created for your air conditioning unit. You do not need a special circuit, but the electrical wire should run to the breaker you installed that is specifically designated for your walk-in cooler and nothing else. You can use any size air conditioner unit, but it needs to be at least 18,000 BTUs to sufficiently cool an 8x8x8 cooler.
Install particle board to the outside of your wall frames and the ceiling, using wood screws. Your cooler should now be completely enclosed. Add fiberglass insulation in the two-inch spaces between the 2x4 planks on the walls, ceiling, and floor, using staples.
Lay down your vinyl floor, then install your insulation board to the walls and ceiling using liquid nails and glue. Glue the vinyl wallboard to the walls, inside and out.
Install the air conditioning unit by fitting it in the opening you cut into your frame and attaching the cabling behind the unit to the breaker you designated earlier. The unit should come with screws that allow it to be attached securely to the wall. Set the thermostat on the air conditioner between 35 and 45 degrees Fahrenheit.