867
Glossary
I
incandescent light: The traditional screw-in
lightbulb that relies on a glowing fi lament to
provide light.
individual circuit: A branch circuit dedicated to
a single appliance that requires a large amount
of electricity, such as an air conditioner or
clothes dryer.
Indoor Radon Abatement Act: A law passed
in 1988 that set a goal for the Environmental
Protection Agency to reduce indoor radon
levels to those of outdoor air.
infi ltration: The amount of heat lost through
spaces around windows and doors.
inlet: A cold air return for a forced-air climate
control system.
inner hearth: The part of a hearth that makes
up the fl oor of the fi replace.
insulated concrete forms (ICFs): Concrete wall
forms made of foam insulation that are fi lled
with concrete and remain in place to become
part of the exterior wall structure.
insulation: A material that prevents heat or
cold from transferring from one location to
another.
interior designer: A designer who specializes in
the interior detailing of structures, including
architectural highlights such as half-walls or
recessed lighting.
intermediate level: The level located between
the basement level and the living level of a
split-level house.
ion exchange: A process used in water softeners
in which sodium ions in a resin are exchanged
for calcium and magnesium ions, reducing
the hardness of the water.
island kitchen: A modifi cation of a straight-
line, L-shaped, or U-shaped kitchen that
includes a freestanding island. The island
may house the sink, cooking center, or food
preparation center, and may also serve as an
eating area.
J
jack stud: A structural member positioned
inside a wall opening to help support the
header over the opening; also called a trimmer.
heating, ventilation, and air conditioning
(HVAC) plan: A plan that shows components
of the climate control system of a house.
hidden line: Thin, dashed line that represents
an edge that is behind a visible surface in a
given view.
hopper window: A window that is hinged at the
bottom and swings to the inside of the house.
horizon line (HL): The line formed where the
ground and sky meet in the background of
a perspective drawing.
horizontal furnace: A furnace that can be
suspended from ceilings and fl oor joists or
installed on a concrete slab because it requires
minimum clearance.
hot water branch lines: Pipes that run from
the hot water main to each of the fi xtures in
a residential water supply system.
hot water main: The pipe in a residential water
supply system that branches off the house
main, runs through the water heater, and then
runs throughout the house to supply hot water
branch lines.
house drain: The main drain pipe that receives
water and waste from all of the stacks; becomes
the house sewer after it passes to the exterior
of the house.
house sewer: The part of the house drain that
runs from the house to the city sanitary sewer
or a private septic system.
housed stringer: A stringer that has been
routed or grooved to receive the treads and
risers of a stairway.
hurricane code: A building code designed to
reduce property damage during a hurricane
by requiring structures to be constructed to
withstand hurricane-force winds.
hurricane tie: A strap or clip that anchors roof
components to a house. Hurricane ties help
the roof withstand the high winds typical of
hurricanes and tornadoes.
hydronic radiant system: A type of hydronic
heating system that has copper pipes or other
type of tubing embedded in a concrete fl oor
or plastered ceiling.
hydronic system: A hot water heating system.