Louvred
Windows.--Few things have remained status quo during the past 450 years, but the "double hung" window, most commonly used today, has remained essentially unchanged since it made its first appearance in England somewhere in the 1400's.
Here in America, this window design based on an upper and lower sash that slides up and down has been used for centuries, despite its many shortcomings. Besides admitting light and air, the window has the obvious function of creating ventilation. When considering the important air flow factor, the "double hung" window leaves much to be desired. Offering only a 50 per cent maximum opening, this window permits the air to enter and continue only on a horizontal level inside the room, or in the same direction as the outside source. By adjustments of the sash, the air can enter the room at various horizontal levels from top to bottom.
Only recently, since the Sun Sash Company (N. Y. C.) introduced their louvred window in this country, has a completely new window design become available to architects and builders. Blending with the current architectural trend toward functional design, the louvre principle affords 100% ventilation when fully opened. Even when partially opened, drafts are eliminated because the air is directed inside to any upward angle at which the glass louvres are adjusted. When partially open, the cool outside air is directed toward the ceiling, displacing collected warm air and maintaining more uniform room temperatures. In addition, the Sun-Sash window possesses the unique ability of directing the air horizontally or downwards as well, allowing installation at different heights with little or no effect upon the maximum benefits to be received from it. Many hospitals have realized this important advantage by choosing the louvred window.
An examination of the Sun-Sash window indicates that it consists of two heavy galvanized steel uprights with rotatable pockets mounted on bronze bearings. These pockets are designed to accommodate 6" glass louvredblades. A single lever, operating through a concealed linkage, permits all the louvres to be opened simultaneously by applying finger-tip pressure. These louvres remain in any desired position and lock automatically in the close position. A very broad comparison can be made between the operating theories of the louvred window and the venetian blind.
Strong support for the Sun-Sash window comes from the lady of the house on four important points. First, children cannot fall out and secondly, burglars cannot enter. The third point--left open during rain storms, the Sun Sash window practically eliminates the danger of water infiltration and consequent damage to draperies and furniture. Even in the closed position, condensation or "sweating" does not occur on the inside surfaces. Another factor she appreciates is the ease with which outside surfaces are cleaned from the inside.
The low installation price of the louvred window has been a very strong contributing factor to its current acceptance by the building industry. Also, broken window panes are easily replaced without special tools or skills. It's only necessary to slide a new pane into the pocket.