Walk-in coolers are a staple for restaurants and bars. Problem is, they're expensive! Usually $10,000 and up and the maintenance costs can add up fast. Coolbot is a little computer that can turn an off-the-shelf air conditioner into a DIY walk-in cooler.
Coolbot uses sensors to trick the A/C unit into bringing the room temperature as low as 34 degrees. It also manages the unit to make sure it doesn't freeze up. The company says setup takes 10 minutes or less. Most of your time will be spent building an insulated room to use as your cooler. Typically the entire setup with the Coolbot, an A/C unit and construction of an insulated room will cost about $3,000.
You can buy Coolbot directly from their site for $315.