Hopper Windows: The Underground Window
December 29, 2009
Hopper windows - you probably have them and didn't even know it. Hopper windows are typically found in basements. They are hinged at the base and tilt open and in at the top. It allows ventilation to lower levels of the home and generally has a screen to keep dirt, leaves and debris from blowing into the basement.
The hopper window is similar to a casement window in that it doesn't have sliding seals like a typical double hung window or sliding window. This offers maximum energy efficiency as the air leakage is minimized since it uses a compression seal instead. The compression seal is basically an airtight seal that is formed when the window is closed and compressed into the seal, which isn't possible in windows that slide and glide open and shut.
Since hopper windows are typically located in a high, difficult to reach areas, many can be operated with a crank mechanism, much like an awning window or casement window would. The crank mechanism can be extended to make easy work of opening and closing hopper windows in hard to reach locations.
In fact, the design of the hopper window is based on the old transom windows of the 19th Century. A transom window is located above the top beam, or transom, of a window or door. In Victorian architecture the hopper window was a transom window that was typically found above the door. It allowed ventilation into the home while keeping the dirt and dust from the nearby roads, which of course were not paved, out of the home. Hopper windows offer a convenient, self contained, energy efficient option in basement windows.