> And you’re not going to be able to stop a cook from opening the oven door on occasion—peeking through a grease-splattered window just doesn’t cut it. But designers could prevent that blast of cold air by building a blower into the door frame that generates a “curtain” of air whenever the door is opened, retaining more of the preheated air in the oven. Larger versions of air doors are already in wide commercial use for refrigerated warehouses.

Whoa, isn't this also used in supermarkets when you enter them?