How to make a homemade air door / curtain?
You might have seen them on your favorite super market. When you enter the store you get hit by an air current from above. They help prevent pests from coming inside the store and also keep the cold/warm air inside. The price for one of these units is ridiculous!! at least for home applications. They range from $200 to $3,000 depending on the size and air current speed. I can visualize a wood box with the aperture on it for the air to come out but the insides would be a bit hard to find under $200. Maybe one of those standing fans? I don't plan on doing the instructable but it would be nice if someone would ^_^.