G L O S S A R Y O F T E R M S
A.G.A.:
American Gas Association
Air-Fuel Ratio:
The ratio of weight or volume of
air to fuel.
Ambient Air:
The atmosphere external to fur-
nace, appliance or process.
ASHRAE:
American Society of Heating,
Refrigeration and Air
Conditioning Engineers
British Thermal
The amount of heat required to
Unit:
raise 1 pound of water 1°F.
Calibration:
Comparison of an instrument of
lesser accuracy with another stan-
dard of known accuracy (calibra -
tion gas) to detect, correct and
adjust for instrument accuracy.
Calorie:
The amount of heat required
to raise 1 gram of water 1°C.
Carbon Dioxide:
A colorless gas, heavier than air,
formed by the complete combus-
tion of carbon.
CO:
The chemical symbol for carbon
monoxide.
CO
2
:
The chemical symbol for carbon
dioxide.
Combustion
A fuel-burning (oil, gas, coal or
Appliance:
wood) device such as a range,
furnace, boiler or water heater.
Combustion Air:
The air supplied for combustion
of the fuel.
Combustion
The portion of the heating or
Chamber:
process equipment where fuel is
burned.
Dampers:
C o n t rols that vary air flow thro u g h
an air outlet, inlet or duct.
DOE:
Department of Energy
Environmental
Conditions other than indoor air
Factors:
contaminants that cause stress,
d i s c o m f o rt and/or health pro b l e m s
(e.g. humidity extremes, drafts
and lack of air circulation).
EPA:
Environmental Protection Agency
Excess Air:
Air supplied for combustion in
excess of that theoretically
required for complete oxidation
of the fuel.
Flue:
A passageway for conveying
combustion products to the
outside air.
Flue Gases:
Gaseous products of combustion.
Heat Exchanger:
A device that transfers heat from
one system to another, such as in
a warm air furnace.
IAQ:
Indoor Air Quality
Incomplete
Combustion in which fuel is only
Combustion:
partially burned and is capable of
being further burned under pro p e r
conditions of temperature and air.
Indoor Air:
The air that occupies the space
within the interior of a house or
other buildings.
Makeup Air:
Outdoor air supplied into a build-
ing to compensate for air which is
exhausted by combustion appli-
ances or other devices such as
exhaust fans.
NO:
The chemical symbol for
Nitric Oxide.
NO
2
:
The chemical symbol for
Nitrogen Dioxide.
OSHA:
Occupational Safety and Health
Administration
Orsat:
A gas analysis apparatus in which
the CO
2
or O
2
gaseous constituents
a re measured by absorption in
separate chemical solutions.
Oxides of Nitrogen The sum of NO (Nitric Oxide)
(NO
X
):
and NO
2
(Nitrogen Dioxide).
Perfect Combustion The combining of the chemically
( S t o i c h i o m e t r i c ) :
c o rrect pro p o rtions of fuel and air
in combustion so that the fuel
and oxygen are both totally
c o n s u m e d.
Plenums:
Enclosures for the collection of
air at the termination or origin
of duct systems.
Primary Air:
Air mixed with the fuel inside
the burners.
Secondary Air:
Air for combustion supplied
to the outside of the flame to
supplement the primary air.
SO
2
:
The chemical symbol for sulfur
dioxide.
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