This invention relates to the production of air curtain barriers across building openings, such as doors and windows, to reduce both winter and summer energy losses.
It has heretofore been proposed to provide apparatus for accomplishing this result. See, for example, U.S. Pat. Nos. 3,059,563; 3,086,441; 3,156,641; 3,157,105; and 3,327,935.
The prior art devices, so far as I am aware, all attempt to produce a downwardly directed relatively homogenious sheet or layer of moving air across the opening in question, in the belief that such a sheet or layer would form the most effective barrier to energy transfer in either direction.
I have discovered that a more effective barrier comprises a series of side-by-side, preferably oppositely rotating, pressurized air swirls across such an opening. By its very nature, swirling air, like a whirlwind, tends to maintain its integrity and to resist disruption by outside forces. Side-by-side oppositely rotating swirls tend to reinforce each other, further to maintain their integrity and to resist disruption. The present invention employs these phenomena to great advantage in providing a much improved and more efficient barrier of the air curtain type.