Head track:
The track provided at the head of a sliding glass door. Also, the head member incorporating
the track.
Header:
The upper horizontal member of a window frame. Also called head.
Heat-absorbing glass:
Window glass containing chemicals (with gray, bronze, or blue-green tint) which
absorb light and heat radiation, and reduce glare and brightness. See also Tinted
glass.
Heat gain:
The transfer of heat from outside to inside by means of conduction, convection,
and radiation through all surfaces of a house.
Heating degree day:
Term used by heating and cooling engineers to relate the typical climate conditions
of different areas to the amount of energy needed to heat and cool a building. The
base temperature is 65 degrees Fahrenheit. A hating degree day is counted for each
degree below 65 degrees reached by the average daily outside temperatures in the
winter. For example, if on a given winter day, the daily average temperature outdoors
is 30 degrees, then there are 35 degrees below the base temperature of 65 degrees.
Thus, there are 35 heating degree days for that day.
Heat loss:
The transfer of heat from inside to outside by means of conduction, convection,
and radiation through all surfaces of a house.
Heat-strengthened glass:
Glass that is reheated, after forming, to just below melting point, and then cooled,
forming a compressed surface that increases its strength beyond that of typical
annealed glass.
Hinged windows:
Windows (casement, awning, and hopper) with an operating sash that has hinges on
one side. See also Projected window.
Hopper:
Window with sash hinged at the bottom.
Horizontal slider:
A window with a movable panel that slides horizontally.
ICC:
International Code Council. A national organization that publishes model codes for
adoption by states and other agencies. Codes include the International Building
Code (IBC) and the International Energy Conservation Code (IECC).
IECC:
International Energy Conservation Code published by the ICC. The successor to the
Model Energy Policy Act (EPAct) as the baseline for residential Energy Codes in
the United States.
Infiltration:
See air leakage.
Infrared radiation:
Invisible, electromagnetic radiation beyond red light on the spectrum, with wavelengths
greater than 0.7 microns
Insulated shutters:
Insulating panels that cover a window opening to reduce heat loss.
Insulating glass:
Tow or more pieces of glass spaced apart and hermetically sealed to form a sing
glazed unit with one or more air spaces in between. Also called double glazing.
Insulating value:
See U-factor.
Insulation:
Construction materials used for protection from noise, heat, cold or fire.
Interlocker:
An upright frame member of a panel in a sliding glass door which engages with a
corresponding member in a adjacent panel when the door is closed. Also called interlocking
stile.
Jalousie:
Window made up of horizontally-mounted louvered glass slats that abut each other
tightly when closed and rotate outward when cranked open.
Jamb:
A vertical member at the side of a window frame, or the horizontal member at the
top of the window frame, as in head jamb.
Krypton:
An inert, nontoxic gas used in insulating windows to reduce heat transfer.
KWH:
Kilo Watt Hour. Unit of energy or work equal to one thousand watt-hours.
Laminated glass:
Two or more sheets of glass with an inner layer of transparent plastic to which
the glass adheres if broken. Used for safety glazing and sound reduction.
Lift. Handle:
For raising the lower sash in a double-hung window. Also called sash lift.
Light:
A window; a pane of glass within a window. Double-hung windows are designated by
the number of lights in upper and lower sash, as in six-over-six. Also spelled informally
lite.
Light-to-solar-gain ratio:
A measure of the ability of a glazing to provide light without excessive solar heat
gain. It is the ratio between the visible transmittance of a glazing and its solar
heat gain coefficient. Abbreviated LSG.
Lintel:
A horizontal member above a window or door opening that supports the structure above.
Liquid crystal glazing:
Glass in which the optical properties of a thin layer of liquid crystals are controlled
by a en electrical current, changing from a clear to a diffusing state.
Long-wave infrared radiation:
Invisible radiation, beyond red light on the electromagnetic spectrum (above 3.5
micro meters), emitted by warm surfaces such as a body oat room temperature radiating
to a cold window surface.
Low-conductance spacers:
An assembly of materials designed to reduce heat transfer at the edge of an insulating
window. Spacers are placed between the panes of glass in a double-or triple-glazed
window.
Low-emittance (low-E) coating:
Microscopically thin, virtually invisible, metal or metallic oxide layers deposited
on a window or skylight glazing surface primarily to reduce the U-factor by suppressing
radiative heat flow. A typical type of low-E coating is transparent to the solar
spectrum (visible light and short-wave infrared radiation) and reflective of long-wave
infrared radiation.
Meeting rail:
The part of a sliding glass door, a sling window, or a hung window where two panels
meet and create a weather barrier.
Metal-clad windows:
Exterior wood parts covered with extruded aluminum or other metal, with a factory-applied
finish to deter the elements.
Micron:
One millionth (10-6) of of a metric meter.
Mil:
One thousandth of an inch, or 0.0254 millimeter.
Model Energy Code (MEC):
The Model Energy Code is cited in the 1992 U.S. Energy Policy Act (EPAct) as the
baseline for residential Energy Codes in the United States. It has been succeeded
by the International Energy Conservation Code (IECC) published by the International
Code Council (ICC).
Mullion:
A major structural vertical or horizontal member between window units or sliding
glass doors.
Muntin:
A secondary framing member (horizontal, vertical, or diagonal) to hold the window