Argon Gas: This is an inert gas that is inserted into the space between the glass. The gas is less dense than air and therefore transmits heat and sound at a slower rate. This adds to the sound proofing of the window and adds to the insulation value. Over time this gas will dissipate thereby losing it's value.

Bi-Glass System®: A window renovation system in which the single pane glass is replaced with insulated glass while retaining the original sash and a vinyl jambliner system replaces the old weight and pulley or friction balance system.

Hidden Balances: These are balances that are cut into the side of the sash and attach to the jamb so that they remain hidden from view at all times.

Infiltration: This refers to the air that leaks around the sash and works it's way into the weight pocket area in the wall. This infiltration makes up 2/3's of the heat loss in a standard single pane window.

Insulated Glass: This is two pieces of glass that are bonded together using aluminum, foam, or butyl spacers. They do not have a vacuum between the glass, but either air or argon gas. They come in different thicknesses depending upon the application.

Jambliner: The jambliner consists of a vinyl unit that has spring balances installed into it to balance the window sash in its operation. This replaces the old weight and pulley system . They have a foam backing to prevent infiltration and weather-stripping to prevent air leakage at the meeting rails.

Low E Glass: A major cause of winter cold spots and drafts is window glass. Here's what happens: When it's 0 degrees Fahrenheit outside and 70 degrees in the room, the inside surface of the glass in a single pane window is a very chilly 14 degrees! You feel a cold spot next to the window. The cold spot interacts with the warm air, setting up currents which cause cold drafts. Under the same winter conditions with "Comfort-E" low-E glass, heat reflected by the glass warms the inside pane of double pane windows to about 56 degrees. Cold spots are drastically reduced, so there's little opportunity for convection currents to develop or for condensation to form. Low E glass is glass with coating of tin oxide applied to the surface of the interior pane. The coating also adds in the "R" Value increasing the insulation value of the glass by up to 10%. The coating also reflects approximately 60% of the ultraviolet rays out of the house thereby reducing fading of carpets, floors and furniture.

Meeting Rails: The meeting rails are the horizontal parts of the sash that meet each other in the center of the sash.

Muntin: A muntin is the grid work that separates the panes of glass in a sash.

Rail: The rails of the sash are the horizontal pieces.

"R" Value: This refers to the resistance to heat loss of any object. This is the measuring system used to specify and grade insulated glass. Single pane glass has virtually no R value while insulated panels 7/16" to 3/4" thick range from 1.87 to 2.9.

Sash: This is the wooden operable part of the window, that holds the glass in place.

Sash Locks: There are a variety of locks for window sash. The standard is a cam lock with a definite modern look. Reproduction brass locks are also available.

SDL/Simulated Divided Lights: This is a term used to describe a sash that is no longer true divided (many individual pieces of glass in one sash) but has muntins applied permanently to the interior and exterior. In some cases there is a spacer grid placed between the glass panels in the insulated glass that match the muntin pattern.

Silicone bulb weather-stripping: This weather-stripping is a silicone product that is used to seal the horizontal joints of a window sash. It has virtually no memory therefore retains it shape even after being compressed all winter long.

Stile: The stiles of a window sash are the two vertical pieces of the sash

Tape Balance: Tape balances have been used for over a hundred years and take the place of the weight and pulley system. They are mounted in the pulley holes and have a flat spring tape that replaces the sash cord. this system is good for large windows where vinyl is not an option.

Vinyl Windows: Window made completely of extruded vinyl.

Weight Pockets: These are the pockets the weights are housed in. They are filled with insulation when the weights are removed.