Air Space: All high-performance windows have at least 2 panes of glass sandwiched together with an air space in between. The size of the air spaces affects the overall performance of the window. A ½” to ¾”­­­ space is considered optimal.

Air Vent: Optional exchange vent installed in header.

Argon Gas: An odorless, colorless gas pumped into IG units to give additional insulating values.

Awning: A widow style hinged at the top that opens out. Standard abbreviation: AW

Balance Shoe: The receiving piece connecting the Constant Force balance to the sash; also referred to as Pivot Shoe.

Bay Window: An arrangement of 3 individual window units attached in such a way as to project away from the building at 30° or 45°angles. In a 3 lite unit, the center section is usually fixed with the end panels operable as casement or vertical sliders. Standard abbreviation: BAY (CS/PW/CS­—SH/PW/SH—DH/PW/DH EXAMPLES)

Bead: A continuous strip of caulking or glazing material.

Block Frame: Main frame of window without integral nailing fin.

Block & Tackle Balance: Hardware used to operate sash in Single or Double Hung windows; less reliable and no field adjustment option. Additional visual clips exposed on interior of finished window. Allows the side loading of sash only and no tilt feature.

Bow Window: A multi-lite mulled window system, similar to Bay with a small angle such as 13°. Any combination of windows can be used, all units the same size. Standard abbreviation: BOW (SH/PW/SH—PW/PW/PW/PW EXAMPLES)

BTU: British Thermal Unit. The energy used for heating and cooling is measured by the number of BTUs needed to keep a building at a comfortable temperature. Scientifically, it is the amount of heat energy necessary to raise the temperature of one pound of water one degree Fahrenheit.

Butyl: Polyisobutylene is a hot-melt sealant and is used as the primary moisture seal for dual-seal systems.

Cam Lock: Security lock attached to top of lower sash on vertical sliders or side of inner sash on horizontal sliders.

Casement: A window style that is a single unit of glass, usually larger vertically than horizontally, opening to the inside and hinged on the left or right. Standard abbreviation: CS

CFM: The number of cubic feet of air leakage per minute per each lineal foot. The lower the CFM rating, the less drafty the window.

Commercial Guarantee: Commercial property is defined as any structure of 3 or more living units or any structure used for purposes other than residential dwelling. LbL Windows will guarantee in writing all parts and labor for 5 years from date of original purchase.

Condensation: When water vapor, which is present in all but the driest of air, comes in contact with a surface that is below what is called the “dew point temperature”, the vapor becomes liquid and is called condensation.

Constant Force Balance: The hardware system used to operate vertical sash in Single or Double Hung windows. Stainless steel clock spring factory calibration offers smooth, effortless and reliable operation.

Custom Sizes: All windows and doors produced by LbL Windows are custom manufactured to specifications supplied by our customers to measurements within 1/8”.

Desiccant: An extremely porous crystalline structure used to absorb moisture from within the sealed air space of an insulated glass unit.

Double Hung: A vertical window style which allows both sashes to operate. LbL Windows Series 8000 uses Constant Force Balance hardware that allows both sashes to tilt into the room for easy cleaning. Not all Double Hung style windows offer the tilt feature. Standard abbreviation: DH

Egress: A way out, exit or outlet.

Egress Formula: Minimum 5.7 square feet of clear egress with a minimum width of 20” and height of 24” and sill height no greater than 44” above finished floor. (Note: All requirements must be met for egress compliance.)

Expanding Foam: Product used by some contactors to fill all air cracks. Use not recommended with vinyl windows as it can expand too much, causing many operational problems with windows. Use of expanding foam causes operational problems and will void the LbL Guarantee.

Extrusion: The process of forcing raw material through a die or series of dies to shape desired designs; also, any item made this way.

Fixed Window: A window which is stationary; also known as a Picture Window. The part of a sliding window or door which is non-moveable; also known as inactive (i.e. fixed panel or fixed lite).

Fogged Unit: A deposit of contaminants on the interior of the glass surface of an insulating unit.

Foil: Metal with width 0.005” thick or less.

Frame: The exterior portion of a window; sometimes called the Main Frame.

Fresh Air Vent: See Air Vent.

Gable Window: A window that follows the roofline with at least 2 non-90° corners.

Garden Window: A window box normally with Single Hung units on sides, front and top fixed units and a bottom panel of hard surface; also includes an interior shelving system. Available in both aluminum and vinyl frame units. Standard abbreviation: GW

Geometric Shapes: Specially shaped windows like round, half round, arched, triangular, trapezoidal, octagonal and hexagonal. Special care must be given to size parameters. Always recommended that customer supply a drawing with dimensions. Some limitations on grid options may apply. Many shapes are mulled to other window styles; check parameters on mulling requirements and limitations.

Glass–Amber: A yellowish colored glass sometimes textured for privacy and design. Standard abbreviation: AMB

Glass–Annealed: Standard sheet or float glass.

Glass–Low E: Low Emissivity is a metal coating applied to glass to reflect UV rays, increasing the efficiency of the glass. Standard abbreviation: LE

Glass–Single Strength: 3/32” (2.5mm) normal thickness; industry standard. Standard abbreviation: SSB

Glass–Laminated: 2 or more sheets with an inner layer of plastic to which the glass adheres if broken. Usually used for overhead, safety glazing and sound reduction.

Glass–Double Strength: 1/8” thickness (3.00mm). Minimum Standard glass in LbL Window products. Standard abbreviation: DSB

Glass–Obscure: Frosted or textured, mainly used for decoration, privacy or diffusion. Normally used in bathrooms for privacy. Standard abbreviation: OBS

Glass–Tempered: Glass that has been reheated to just below the melting point, then suddenly cooled. When shattered, tempered glass breaks into small pieces. It is approximately 5 times stronger than standard Annealed Glass. It is used in safety glazing on patio doors, entrance doors, side lites and other hazardous locations. Once tempered, glass cannot be cut. Standard abbreviation: TEMP

Glaze–Inside: Glazing bead position is on the interior of window. Glazing tape position is on the outside of IG unit. Replacement of IG unit can be performed from the inside of the structure.

Glaze–Outside: Glazing bead is on the outside of window. Glazing tape position is on the interior of IG unit. Replacement of IG unit can be performed from the outside of the structure.

Glazing Bead: A molding or stop around the inside of a frame to hold the glass in place.

Grids: Use of aluminum or vinyl muntin bar between lites of glass in a sealed glass unit to simulate cut-ups or individual lites. Standard abbreviation: GRID

Header: The upper horizontal portion of the master frame of a window, patio door or entranceway.

Header Expander: An adjustable part attached to the header or frame of a replacement or storm window that can be adjusted to fill any gap between the new window and the existing opening.

Heel Size: Actual net window dimension. Most heel dimensions are ½” smaller that the rough opening dimensions.

Horizontal Slider: A window where the operable panel(s) slide horizontally. LbL Windows offers Single, Double and Triple options (refer to product literature for specific Series information). Standard abbreviation: XO–OX Single Slider, XX–2X Double Slider, XXX–3XTriple Slider

Humidity: A measurement of the amount of moisture contained in the air.

IG Unit: Insulated Glass Unit. Standard abbreviation: IG

Interlock: Overlapping fin at sash meeting rails to eliminate air infiltration.

Jamb: Side portion of main frame.

Jamb Jacks: Adjustment hardware used with Double Hung windows to align side rails and eliminate twisting or bowing of frame.

Limited Guarantee Plus: LbL Windows guarantees in writing all parts and labor against manufactured defects for the life of the original homeowner and will extend this guarantee for 2 years to the second homeowner. The guarantee extends to all parts, hardware and failed IG units. This guarantee applies to residential structures and attached living units owned by 1 individual. For structures with 3 or more living units, refer to the Commercial Guarantee.

Lift Rail: The integral part of the sash used to raise and lower the sash.

Lineal: The extruded parts purchased from outside required to manufacture windows.

Lite: Another term used for a pane of glass used in a window.

Meeting Rail: The center bar on the 2000 Series SH & XO. This rail has an extruded aluminum bar inserted on all windows for structural strength. For the 8000 Series, the meeting rail is the point at which the top of the lower sash meets the bottom of the upper sash.

Mull: To join 2 or more windows together.

Mull Bar: Driven into Mull Groove of each window, both on the face and interior, to attach 2 or more windows together.

Mull Groove: A factory extruded groove needed to mull 2 or more windows and attach accessories like a stucco fin, a channel, a Mull Bar, a Sill Extender, etc.

Multi-point Hardware: Optional locking hardware system for rolling patio doors.

Muntins: See Grids.

Net Size: Actual window size; also referred to as Heel Size.

NFRC: The National Fenestration Rating Council was developed several years ago to promote the standardization of window, door and skylight testing and reporting methods. The NFRC U Value program combines accurate simulation and testing with certification and labeling of products.

Nailing Fin: Extruded fin on window for application attachment. Factory removal at no charge.

Patio Door: Rolling Door available in a variety of configurations and lengths up to 16 feet. Standard abbreviation: XO–OX–OXO–OOX–XOO–OXXO

Patio Conversion Kits: IG units built to replace existing single glazing units in existing patio door frame. Available in black vinyl adapter with 5/8” OA Unit or aluminum adapter with ¾” OA Unit.

Picture Window: 1 frame with 1 IG unit, sometimes referred to as Fixed Window. Standard abbreviation: PW

PVC: Polyvinyl Chloride, the material we call vinyl.

R Value: A measurement of resistance to heat gain or loss (insulate ability). R Values, rather than thickness, can be compared for different materials. 6” of fiberglass (R=19) might compare with 12” of wood or 18” of stone.

Rip Fin: The removal of the Nailing Fin for wood windows, stucco and other installation situations; sometimes referred to as Block Frame (removed by LbL Windows at no charge).

Rollers: Small wheels supporting a horizontal sash for easy, trouble-free operation. Most common are plastic or brass wheels (LbL Windows utilizes a dual tandem 316 stainless steel wheel roller system).

Rough Opening: The size of the opening for which the window is framed. The Heel or Net Size of the window is usually ½” smaller than the Rough Opening.

Sash: The operating portion of a window which includes the glass; also referred to as Vent.

Setting Block: A plastic block used to support the insulating unit in the window frame.

SIGMA: Sealed Insulated Glass Manufacturers Association.

Sill: The bottom section of the window main frame.

Sill Extender: An accessory part that locks into the Mull Groove at the bottom of the window frame to fill area of an opening with a sloping sill.

Single Hung: Similar to the Double Hung in appearance, the Single Hung is a vertical operating window with the lower sash operable and the upper glass fixed in the frame. Standard abbreviation: SH

Spacer–Aluminum: Standard spacer for most new construction Block Frame windows. Lowest efficiency spacers.

Spacer Super Series™: A superior Warm Edge spacer made from organic foam with acrylic construction adhesives that seal to both pieces of glass from Edgetech®.

Spiral Balance: A smooth operating system for Single or Double Hung windows. Advantages include on-site operation adjustment, tilt feature for ease of cleaning and longer life than ordinary Block & Tackle balance system.

Storm Door: Aluminum door installed over existing prime door.

Storm/Security Door: Aluminum storm door with aluminum outside security grid and deadbolt hardware installed over existing prime door.

Storm Window: Aluminum window custom manufactured to install outside or inside existing prime window.

Storm–Horizontal Slider: Aluminum window custom manufactured to install outside existing prime window.

Storm–Picture: Aluminum window custom manufactured to install outside or inside existing prime window.

Storm–Single & Double Hung: Aluminum window custom manufactured to be installed outside existing prime window.

Tempering Guidelines: Any glass within a 24” arch of any door; any glass within 60” from the bottom of a tub or shower; any glass within 18” of the floor.

Three-Light Slider: Horizontal slider with 2 operating sashes on ends and fixed center panel. Normal proportions 1/4–1/2–1/4. Standard abbreviation: XOX Note: Double Slider abbreviation can be XXX; all sashes move and tilt into room.

Tilt Latch: Hardware on top sash panels employed to release and tilt sash panel.

Tilt ‘N’ Slide™: Track hardware with tilt latches allowing sliding sash panels to tilt or pivot into room. Track hardware has 6 brass rollers per sash.

United Inches: The total of the largest width and largest height of a window expressed in inches.

U Value: The measurement used to determine the ability of structural components (such as windows) to conduct heat. The U Value of a window is measured by the number of BTUs that will pass through each square foot of area per degree of temperature difference from one side of the window to the other. U Values can tell you how well your windows will hold in the heated or cooled air. The lower the number, the better.

Vent Stop: Available on some models of Hung or Slider Windows (refer to product specifications for specific models). Two latches standard on all Hung Windows and one on lower portion of slider for child protection. These are intended for use as ventilation stops only and not recommended for security applications.

Vent Panel: Also known as Sash or Sash Panel.

Warm Edge: The term applied to IG Units using a non-metal spacer for increased R & U Values, increasing efficiency of windows and reducing condensation.

Weather-stripping: Normally a fibered fin product to reduce air and water filtration.

Weep Holes: Slots or holes in the sill member of a window frame to provide outdoor release of infiltrated water.