HomeMy WebLinkAbout2015 IRC Definitions - Dwelling UnitDRAFT. The pressure difference existing between the appli-
ance or any component part and the atmosphere, that causes a
continuous flow of air and products of combustion through
the gas passages of the appliance to the atmosphere.
Induced draft. The pressure difference created by the
action of a fan, blower or ejector, that is located between
the appliance and the chimney or vent termination.
Natural draft. The pressure difference created by a vent
or chimney because of its height, and the temperature dif-
ference between the flue gases and the atmosphere.
DRAFT HOOD. A device built into an appliance, or a part
of the vent connector from an appliance, that is designed to
provide for the ready escape of the flue gases from the appli-
ance in the event of no draft, backdraft or stoppage beyond
the draft hood; prevent a backdraft from entering the appli-
ance; and neutralize the effect of stack action of the chimney
or gas vent on the operation of the appliance.
DRAFT REGULATOR. A device that functions to maintain
a desired draft in the appliance by automatically reducing the
draft to the desired value.
[RB] DRAFT STOP. A material, device or construction
installed to restrict the movement of air within open spaces of
concealed areas of building components such as crawl spaces,
floor -ceiling assemblies, roof -ceiling assemblies and attics.
DRAIN. Any pipe that carries soil and water -borne wastes in
a building drainage system.
DRAIN -BACK SYSTEM. A solar thermal system in which
the fluid in the solar collector loop is drained from the collec-
tor into a holding tank under prescribed circumstances.
DRAINAGE FITTING. A pipe fitting designed to provide
connections in the drainage system that have provisions for
establishing the desired slope in the system. These fittings are
made from a variety of both metals and plastics. The methods
of coupling provide for required slope in the system.
DUCT SYSTEM. A continuous passageway for the trans-
mission of air that, in addition to ducts, includes duct fittings,
dampers, plenums, fans and accessory air -handling equip-
ment and appliances.
For definition applicable in Chapter 11, see Section
N1101.6.
[RB] DWELLING. Any building that contains one or two
dwelling units used, intended, or designed to be built, used,
rented, leased, let or hired out to be occupied, or that are
occupied for living purposes.
[RB] DWELLING UNIT. A single unit providing complete
independent living facilities for one or more persons, includ-
ing permanent provisions for living, sleeping, eating, cooking
and sanitation.
DWV. Abbreviated term for drain, waste and vent piping as
used in common plumbing practice.
EI'F'ECTIVE OPENING. The minimum cross-sectional
area at the point of water -supply discharge, measured or
expressed in terms of diameter of a circle and if the opening
is not circular, the diameter of a circle of equivalent cross-
sectional area. (This is applicable to air gap.)
DEFINITIONS
ELBOW. A pressure pipe fitting designed to provide an
exact change in direction of a pipe run. An elbow provides a
sharp turn in the flow path (see "Bend" and "Sweep").
[RB] EMERGENCY ESCAPE AND RESCUE OPEN-
ING. An operable exterior window, door or similar device
that provides for a means of escape and access for rescue in
the event of an emergency.
[RB] ENGINEERED WOOD RIM BOARD. A full -depth
structural composite lumber, wood structural panel, structural
glued laminated timber or prefabricated wood I -joist member
designed to transfer horizontal (shear) and vertical (compres-
sion) loads, provide attachment for diaphragm sheathing, sid-
ing and exterior deck ledgers and provide lateral support at
the ends of floor or roof joists or rafters.
EQUIPMENT. Piping, ducts, vents, control devices and
other components of systems other than appliances that are
permanently installed and integrated to provide control of
environmental conditions for buildings. This definition shall
also include other systems specifically regulated in this code.
EQUIVALENT LENGTH. For determining friction losses
in a piping system, the effect of a particular fitting equal to
the friction loss through a straight piping length of the same
nominal diameter.
[RE] ERI REFERENCE DESIGN. A version of the rated
design that meets the minimum requirements of the 2006
International Energy Conservation Code.
[RB] ESCARPMENT. With respect to topographic wind
effects, a cliff or steep slope generally separating two levels
or gently sloping areas.
ESSENTIALLY NONTOXIC TRANSFER FLUIDS. Flu-
ids having a Gosselin rating of 1, including propylene glycol;
mineral oil; polydimethy oil oxane; hydrochlorofluorocarbon,
chlorofluorocarbon and hydrofluorocarbon refrigerants; and
FDA -approved boiler water additives for steam boilers.
ESSENTIALLY TOXIC TRANSFER FLUIDS. Soil,
water or giay water and fluids having a Gosselin rating of 2
or more including ethylene glycol, hydrocarbon oils, ammo-
nia refrigerants and hydrazine.
EVAPORATIVE COOLER. A device used for reducing air
temperature by the process of evaporating water into an air-
stream.
EXCESS AIR. Air that passes through the combustion
chamber and the appliance flue in excess of what is theoreti-
cally required for complete combustion.
EXHAUST HOOD, FULL OPENING. An exhaust hood
with an opening not less than the diameter of the connecting
vent.
EXISTING INSTALLATIONS. Any plumbing system reg-
ulated by this code that was legally installed prior to the
effective date of this code, or for which a permit to install has
been issued.
[RB] EXTERIOR INSULATION AND FINISH SYS-
TEMS (EIFS). EIFS are nonstructural, nonload-bearing
exterior wall cladding systems that consist of an insulation
board attached either adhesively or mechanically, or both, to
2015 INTERNATIONAL RESIDENTIAL CODE® 15