Select the first letter of the word from the list above to
jump to appropriate section of the glossary. If the term you are
looking for starts with a digit or symbol, choose the '#' link.
-
- ANSI
American National Standards Institute- ASHRAE
American Society of Heating, Refrigerating and
Air-Conditioning Engineers, Inc. (IESNA)- ASME
American Society of Mechanical Engineers- ASTM
American Society for Testing and Materials- addition
An extension or increase in floor area or height
of a building or to any building system or equipment - albedo, high
A property of a surface that describes its ability to
reflect and reject heat. High albedo surfaces have both a
light color (high solar reflectance) and a high
emmittance (can reject heat back to the environment).
Approved high albedo roof surfaces (typically white in
color and smooth in texture) shall have a minimum total
solar reflectance when tested according to ASTM E-903 of
no less than 0.70. The test sample shall also be tested
for its infrared emittance using ASTM E-408 and have an
emittance no less than 0.75. Testing shall be performed
by an independent laboratory. The roof surface must have
a slope of at least ¼ inch per foot of run. - alteration
Construction or building equipment.: any change,
rearrangement, replacement, or addition to a building or
its systems and equipment; any modification in - area
See roof and wall- astronomical
time switch
An automatic time switch that makes an adjustment for the
length of the day as it varies over the year. - attic and all
other roofs
: see roof.
- Btu
British thermal unit- Btu/h
British thermal unit per hour- Btu/ft2-°F
British thermal unit per square foot per degree
Fahrenheit- Btu/h-ft2
British thermal unit per hour per square
foot - Btu/h-ft-°F
British thermal unit per lineal foot per degree
Fahrenheit- Btu/h-ft2-°F
British thermal unit per hour per square foot
per degree Fahrenheit- building
Any structure used or intended for supporting or
sheltering any use or occupancy. (see also enclosed
building)- building category
The classification of buildings by usage as
follows:
- assembly:
a building or structure for the gathering
together of persons such as auditoriums, places
of worship, dance halls, clubs, courthouses,
gymnasiums, theaters, museums, passenger depots,
transportation stations, sports facilities, and
public assembly halls.
- health
and institutional: a building or
structure for the purpose of providing medical
treatment and research, confinement or care, and
sleeping facilities such as hospitals,
sanitariums, clinics, orphanages, nursing homes,
mental institutions, reformatories, jails, and
prisons.
- lodging: a
building or structure for transient occupancy
such as resorts, hotels, motels, barracks, or
dormitories.
- office
(business): a building or structure for office,
professional, or service type transactions such
as banks and governmental buildings.
- food service
(restaurant): a building or structure for the
consumption of food or drink such as fast-food
services, coffee shops, leisure dining,
cafeterias, bars, and restaurants.
- retail
(mercantile): a building or structure for the
display and sale (wholesale or retail) of
merchandise such as shopping malls, food markets,
auto dealerships, department stores, and
specialty shops.
- school
(educational): a building or structure for the
purpose of instruction such as schools, colleges,
universities, libraries, and academies.
- warehouse
(storage): a building or structure for storage
such as aircraft hangers, garages, warehouses,
storage buildings, and freight depots.
- building entrance
Any doorway, set of doors, turnstiles, or other
form of portal that is ordinarily used to gain access to
the building by its users and occupants.- building exit
Any doorway, set of doors, or other form of
portal that is ordinarily used only for emergency egress
or convenience exit.
- cfm
cubic feet per minute- circulating system
A closed hydronic system consisting of a heating source,
means of pumping, distribution piping, load devices (such
as radiators), and an expansion chamber. In the case of
service water heating, circulating systems typically use
pumps to keep hot water in distribution and therefore
less lag on demand.- class of
construction
For the building envelope, a subcategory of roof or wall
construction.- cooling
capacity,
air conditioners
Typically provided in Btu/h units. Also stated in Tons with a
conversion of 12,000 Btu/h per Ton of cooling capacity.
For example, an air conditioner with 65,000 Btu/h of
cooling capacity is rated at approximately 5.4 Tons.
- DOE
U.S. Department of Energy- damper, flue or
vent
Shut off dampers located on either the exhaust gas flue
or the exhaust gas duct of a gas water heater. The
dampers automatically close the exhaust path when heater
is not firing. This reduces the standby losses from hot
air convection out of the firing chamber.- daylighted area
The area under horizontal fenestration (skylight) or
adjacent to vertical fenestration (window) described as
follows.
- horizontal fenestration area: the area under a
skylight with a horizontal dimension in each
direction equal to the skylight dimension in that
direction plus either the floor-to-ceiling
height, the distance to the nearest 42 in. (1070
mm) or higher opaque partition, or one-half the
distance to an adjacent skylight or vertical
glazing, whichever is least.
- vertical fenestration area: the area adjacent to
a window with one horizontal dimension that
extends into the space either a distance of 15 ft
(4.57 m) or to the nearest 42 in. (1070 mm) or
higher opaque partition, whichever is less; and
another horizontal dimension equal to the width
of the window plus either 2 ft (610 mm) on each
side, the distance to an opaque partition, or
one-half the distance to an adjacent skylight or
window, whichever is least.
- dwelling unit
Any building or portion thereof which contains
living facilities, including provisions for sleeping,
eating, cooking and sanitation for not more than one
family, or a congregate residence for 10 or fewer
persons.
- EER
energy efficiency ratio- EF
energy factor- efficacy
The lumens produced by a lamp/ballast
combination (the product of rated lamp lumen output and
the relative light output of the lamp/ballast
combination) divided by the watts of input power,
expressed in lumens per watt. -
- enclosed building
A building that is totally enclosed by walls,
roofs, floors, windows, skylights, and/or doors.
- F
Fahrenheit- ft
foot- facade
Exterior surface of a building enevlope.- facade area,
vertical
Area of the facade, including non-horizontal
roof area, overhangs, and cornices, measured in elevation
in a vertical plane parallel to the plane of the face of
the building.- fenestration
All areas (including the frames) in the building envelope
that let in natural light, including windows,
clerestories, skylights, sliding or swinging glass doors
that are more than one-half glass, and glass block walls.
- skylight: a fenestration surface having a slope
of less than 60° from the horizontal plane.
Other fenestration, even if mounted on the roof
of a building, is considered vertical
fenestration.
- vertical fenestration: all fenestration other
than skylights.
- fenestration area
Total area of the fenestration measured using
the rough opening and including the glazing, sash, and
frame. For doors where the glazed vision area is less
than 50% of the door area, the fenestration area is the
glazed vision area. For all other doors, the fenestration
area is the door area.
- guest room
Any room or rooms used or intended to be used by a guest
for sleeping purposes.
- h
hour- HC
heat capacity- Hz
hertz, cycles per second- h×ft2-°F/Btu
hour per square foot per degree Fahrenheit per British
thermal unit- heat capacity (HC)
The amount of heat necessary to raise the
temperature of a given mass 1°F. Numerically, the mass
expressed per unit of wall surface multiplied by the
specific heat [Btu/ft2-°F]. - heat trace
A heating system where the externally applied
heat source follows (traces) the object to be heated;
e.g., water piping.- heat trap
Any method or approved device the stops the more buoyant
hot water from circulating through pipes via natural
convection. This can be accomplished with a vertical 360
degree loop in the pipe or a premanufactured heat trap
device.- humidistats
An automatic control device used to maintain humidity at
a fixed or adjustable set point.
- IESNA
Illuminating Engineering Society of North America- in
inch- infiltration
The uncontrolled inward air leakage through
cracks and crevices in any building element and around
windows and doors of a building caused by pressure
differences across these elements due to factors such as
wind, inside and outside temperature differences (stack
effect), and imbalance between supply and exhaust air
systems.
- (empty)
- kVA
kilovolt-ampere- kW
kilowatt- kWh
kilowatt-hour
- lb
pound- LE
lighting efficacy- lin
linear- lin ft
linear foot- lm
lumen- LPD
lighting power density, units watts per square
foot (W/ft2)- lamp lumens, rated
The light output of a lamp as published in
manufacturer's literature. - lamp wattage, rated: the power consumption of a lamp as
published in manufacturer's literature.
- lighting
efficacy (LE)
The quotient of the total lumens emitted from a
lamp or lamp/ballast combination divided by the watts of
input power, expressed in lumens per watt. - lighting, general
Lighting that provides a substantially uniform
level of illumination throughout an area. General
lighting shall not include decorative lighting or
lighting that provides a dissimilar level of illumination
to serve a specialized application or feature within such
area. - luminaire
A complete lighting unit consisting of a lamp or
lamps together with the housing designed to distribute
the light, position and protect the lamps, and connect
the lamps to the power supply. - lumen
Measure of the quantity of luminous flux emitted
by a light source.
- Mass
roof
Mass roofs include concrete of 4 inches or
greater thickness or any other construction with an HC greater than 7.0 or a weight
greater than 35lb/sf2.- Mass
walls
A mass wall has an HC greater than 7.0 or a weight
greater than 35lb/ft2.
- NFRC
National Fenestration
Rating Council-
- non-circulating
system, water heating
Typical service water heating system, in which there is
no hot water flow without any demand. - nonresidential
All occupancies other than residential. (See
residential.)
- occupant sensor
A device that detects the presence or absence of
people within an area and causes lighting, equipment, or
appliances to be regulated accordingly. - optimum start
controls
Controls that automatically adjust the start
time of an HVAC system each day to bring the space to
comfort temperature levels immediately before the
scheduled hour of occupancy.
- PF
projection factor- psig
pounds per square inch gauge- photosensor
A device that measures the amount of incident
light present. Commonly used applications include
automatic switching of exterior lighting and automatic
dimming of interior lights when adequate daylight is
present.- projection factor
The ratio of the horizontal depth of the external shading
projection divided by the sum of the height of the
fenestration and the distance from the top of the
fenestration to the bottom of the farthest point of the
external shading projection, in consistent units. 
- (empty)
- R
R-value (thermal
resistance)- reflectance
The ratio of the light reflected by a surface to
the light incident upon it. - residential
Spaces in buildings used primarily for living
and sleeping. Residential spaces include, but are not
limited to, dwelling units, hotel/motel guest rooms,
dormitories, nursing homes, patient rooms in hospitals,
lodging houses, fraternity/sorority houses, and hostels. - roof
The upper portion of the building envelope,
including opaque areas and fenestration, that is
horizontal or tilted at an angle of less than 60° from
horizontal. For the purposes of determining building
envelope requirements, the classifications are defined as
follows:
- attic and other roofs: all other roofs, including
roofs with insulation entirely below (inside of)
the roof structure (i.e., attics, cathedral
ceilings, and single-rafter ceilings), roofs with
insulation both above and below the roof
structure, and roofs without insulation, but
excluding metal building roofs.
- metal building roof: a roof (1) that is not in
the roof with insulation entirely above deck
category and (2) whose structure consists simply
of metal spanning members supported by metal
structural members (i.e., does not include
composite concrete and metal deck construction.)
- mass roof: a roof with a heat capacity exceeding
7.5 or a weight greater than 40 lb/ft2.
Concrete roofs equal to or greater than four
inches are considered mass roofs.
- roof area, gross
The area of the roof measured from the exterior
faces of walls or from the centerline of walls separating
buildings.
- SHGC
solar heat gain coefficient- SMACNA
Sheet Metal and Air Conditioning Contractors'
National Association- shading coefficient
The ratio of solar heat gain at normal incidence
through glazing to that occurring through 1/8 in.
(3 mm) thick clear, double-strength glass. Shading
coefficient, as used herein, does not include interior,
exterior, or integral shading devices. - solar
heat gain coefficient (SHGC)
The ratio of the solar heat gain entering the
space through the fenestration area to the incident solar
radiation. Solar heat gain includes directly transmitted
solar heat and absorbed solar radiation, which is then
reradiated, conducted, or convected into the space. (See
fenestration area.)
- Tvis
visible light transmission- tandem wiring
Pairs of luminaires operating with lamps in each
luminaire powered from a single
ballast contained in one of the luminaires. - thermal
resistance (R-value)
The mean temperature difference between two
defined surfaces of material or construction that induces
unit heat flow through a unit area under steady-state
conditions. Units of R are h-ft2-°F/Btu. - thermostat
An automatic control device used to maintain
temperature at a fixed or adjustable set point. - tinted
(as applied to fenestration)
Bronze, green, or grey coloring that is integral with the
glazing material. Tinting does not include surface
applied films such as reflective coatings, applied either
in the field or during the manufacturing process.- tons, air conditioners
See cooling capacity.
- UL
Underwriters Laboratories Inc.- UV
ultraviolet- U-factor
(thermal transmittance)
Heat transmission in unit time through unit area
of a material or construction and the boundary air films,
induced by unit temperature difference between the
environments on each side. Units of U are Btu/h-ft2-°F.
- VAV
variable air volume
- W
watt- W/ft2
watts per square foot- Wh
watthour- wall
That portion of the building envelope, including
opaque area and fenestration,
that is vertical or tilted at an angle of 60° from
horizontal or greater. This includes above- and
below-grade walls, between floor spandrels, peripheral
edges of floors, and foundation walls. For the purposes
of determining building envelope requirements, the
classifications are defined as follows:
- mass wall:
a wall with a heat capacity exceeding (1) 7.5
Btu/ft2-°F or a weight exceeding 35
lb/ft2.
- metal
building wall: a wall whose
structure consists of simply metal spanning
members supported by metal structural members
(i.e., does not include spandrel glass or metal
panels in curtain wall systems).
- metal
framing wall: a wall with a cavity
(insulated or otherwise) whose exterior surfaces
are separated by metal framing members (i.e.,
typical metal stud walls and curtain wall
systems).
- wood
framing and other walls: all other
wall types, including wood stud walls.
- wall, gross area
The overall area off a wall including openings
such as windows and doors, measured horizontally from
outside surface to outside service and measured
vertically from the top of the floor to the top of the
roof. If roof insulation is installed at the ceiling
level rather than the roof, then the vertical measurement
is made to the top of the ceiling. The gross wall area
includes the area between the ceiling and the floor for
multi-story buildings. 
- wall, heat capacity
The sum of the products of the mass of each
individual material in the wall per unit area of wall
surface times its individual specific heat [Btu/ft2-°F].
- (empty)
- (empty)
- (empty)
- (empty)
Revised: June 03, 1998.
Copyright © 1995 by [Guam Energy Department].
All trademarks or product names mentioned herein are the property
of their respective owners.