
ACF

Actual Cubic Feet

ACFM

Actual Cubic Feet per Minute

BACT

Best Available Control Technology

BHP

Brake horsepower

BOOS

Burners Out Of Service

BP

Boiling Point

CAA

Clean Air Act

CAAA

Clean Air Act Amendments

CAM

Compliance Assurance Monitoring

CEMS

Continuous Emissions Monitoring System

Cgs

CentimeterGramSecond

DACFM

Dry Actual Cubic Feet per Minute

DSCFM

Dry Standard Cubic Feet per Minute

EPA

Environmental Protection Agency

ESP

Electrostatic Precipitator

FIP

Federal Implementation Plan

HAP

Hazardous Air Pollutant

IPA

Isopropyl Alcohol

ITEQ

International Toxic Equivalency Quotient

LAER

Lowest Achievable Emission Rate

LEL

Lower Explosive Limit

MACT

Maximum Achievable Control Technology

MCE

Mixed Cellulose Ester

NAAQS

National Ambient Air Quality Standards

NESHAPs

National Emission Standards for Hazardous Air Pollutants

NSPS

New Source Performance Standards

NSR

New Source Review

OFA

Overfire Air

OTAG

Ozone Transport Assessment group

OTC

Ozone Transport Commission

PSD

Prevention of Significant Deterioration

QA/QC

Quality Assurance/Quality Control

RAP

Reclaimed Asphalt Pavement

RTO

Regenerative Thermal Oxidizer

SCF

Standard Cubic Feet

SCFM

Standard Cubic Feet per Minute

SIP

State Implementation Plan

TEQ

Toxic Equivalency Quotient

U.S. EPA

United States Environmental Protection Agency

VOC

Volatile Organic Compound
American Engineering System
Heat
1 Btu = 252 cal
Length and Distance
1 in. = 2.54 cm
1 ft = 30.48 cm
1 meter = 100 cm
1 meter = 3.2808 ft
1 mile = 5,280 ft
Mass
1 lb_{m} = 453.6 gm
1 lb_{m} = 7,000 grains
Mole Equivalents
1 lb mole = 453.6 gm mole
Pressure
(at std. conditions, 68°F)
1 atm = 407 in. W.C. =
14.7 psia = 14.7 lb_{f }/in.^{2}=
760 mm Hg = 29.92 in. Hg =
101.325 kPa = 33.92 ft W.C.
Temperature
1°C = 1.8°F
°C = (°F 32)/1.8
°F = 32 + 1.8 (°C)
°K = 273 + °C
°K = °R/1.8
°R = 460 + °F
°R = 1.8(°K)
Viscosity
1 micropoise = 10^{4} cp
1 poise = 100 cp
Volume
1 mL = 1 cm^{3}
1 liter = 0.03531 ft^{3}
1 ft^{3} = 7.481 gal
1 ft^{3} = 28.32 liter
1 m^{3} = 35.31 ft^{3}
Volume to Mass
1 mL of pure water = 1 gm
1 gallon of pure water =
8.34 lb_{m}
1 ft^{3} of pure water = 62.4 lb_{m}
Volume (Gas) @ STP
Volume of 1 lb mole of gas
@ STP = 385.4 ft^{3}
(or 385 ft^{3} rounded)
Volume of 1 gm mole of ideal gas
@ STP = 24.04 liters
(or 24 liters rounded)
Density
Density of city water at standard conditions =
62.4 lb_{m}/ft^{3} or 8.34 lb_{m}/gal
Density of water at 4°C (39.2°F) is 1 gm/cm^{3}
Dissociation
Constant of Water
K_{w} = 1 × 10^{14} (moles/L)^{2}
Universal Gas Constant, R
SymbolDefinition
 A_{STP}
 Fan motor current at standard conditions
 A_{Actual}
 Fan motor current at actual conditions
 A_{Total}
 Total area of fabric filter bags
 BHP
 Brake horsepower (total power consumed by the fan)
 C_{c}
 Cunningham slip correction factor
 C_{e}
 Coefficient of entry
 C_{p}
 Pitot tube coefficient (usually assumed to be 0.84)
 Cp_{x}
 Heat capacity of compound x at constant pressure
 Conc. i_{(Dry)}
 Dry concentration of gas i
 Conc. i_{(Measured O2)}
 Gas concentration at measured oxygen level
 Conc. i_{(Std O2)}
 Gas concentration at standard oxygen level
 Conc. i_{(Wet)}
 Wet concentration of gas i
 c
 Average speed of molecules
 D
 Diameter
 D_{Fan}
 Diameter of fan sheave
 D_{Motor}
 Diameter of motor sheave
 D_{c}
 Diameter of a droplet
 D_{h}
 Hydraulic diameter for rectangular duct
 D_{p}
 Diffusivity of particles
 dv/dy
 Velocity gradient
 d_{pa}
 Aerodynamic particle diameter
 d_{p}min
 Minimum diameter of particles in a particular size range
 d_{ps}
 Stokes particle diameter
 d_{50}
 Diameter of a mediansized particle
 d_{15.78}
 Particle size at 15.78% probability in a lognormal distribution
 d_{84.13}
 Particle size at 84.13% probability in a lognormal distribution
 E
 Voltage
 e
 Base of the natural logarithm
 g
 Gravitational acceleration
 g_{c}
 Factor used when converting between pounds force and pounds mass
 H
 Height of a geometric shape ("h" is sometimes used for cylinders). Also, enthalpy
 H
 Henry's law constant
 h
 Height of a cylinder. Also, height of a fabric filter bag
 h_{e}
 Hood entry loss
 I
 Motor current
 K
 Boltzmann constant
 K_{I}
 Impaction parameter
 K_{w}
 Dissociation constant for water
 L
 Length of a geometric shape. Also, in the gas stream Reynolds number calculation: linear dimension (usually duct diameter).
 MW
 Molecular weight
 MW_{Avg}
 Average molecular weight
 m
 Mass
 N_{Re(g)}
 Gas stream Reynolds number
 n
 Number of moles
 P
 Pressure
 P_{Absolute}
 Absolute pressure
 P_{Actual}
 Gas pressure at actual conditions
 P_{Atm}
 Atmospheric pressure
 P_{Avg}
 Average pressure
 P_{Barometric}
 Barometric pressure
 P_{Gauge}
 Gauge pressure (a relative pressure)
 P_{Relative}
 Relative pressure
 P_{STP}
 Gas pressure at standard conditions
 P_{Total}
 The total pressure of a gas composed of different chemical compounds (the sum of the partial pressures of all component gases)
 P_{j}
 Pressure whose value equals j
 PM_{2.5}
 Particulate matter less than 2.5 micrometers in diameter
 PM_{10}
 Particulate matter less than 10 micrometers in diameter
 p_{f}
 Power factor (phase relationship between current and voltage waveforms)

Q
 Heat required per unit time. Also, volumetric gas flow rate.
 R
 Universal gas constant
 RPM_{Fan}
 Fan speed, revolutions per minute
 RPM_{Motor}
 Motor speed, revolutions per minute
 r
 Radius
 SP
 Static pressure
 Sp. Gr.
 Specific gravity
 SP_{h}
 Hood static pressure
 T
 Temperature
 T_{Absolute}
 Absolute temperature
 T_{Actual}
 Gas temperature at actual conditions
 T_{Avg}
 Average gas temperature
 T_{STP}
 Gas temperature at standard conditions
 T_{i}
 Temperature whose value equals i
 TP
 Total pressure (the combined static pressure and velocity pressure)
 t
 Time
 V
 Volume
 V_{T=i}
 Volume at a specific temperature (i)
 V_{(T=i, P=j)}
 Volume at a specific temperature (i) and pressure (j)
 VP
 Velocity pressure
 v
 Gas velocity. Also, in the impaction parameter equation: difference in velocity
 v_{t}
 Terminal settling velocity
 W
 Width of a geometric shape
 W.C.
 Water column
 x
 Mole fraction of pollutant in liquid phase
 y
 Mole fraction of pollutant in gas phase
 y*
 Mole fraction of pollutant in gas phase in equilibrium with liquid
Greek Symbols
SymbolDefinition

 "Change in." For example T means change in temperature

 Static pressure drop

 Unit shearing stress between adjacent layers of fluid

 Collection efficiency

 Viscosity of gas or fluid at the prevailing conditions

 3.1416

 Density

 Density at actual conditions

 Density of a liquid at a specific temperature (x)

 Density at standard conditions

 Density at a specific temperature (i)

 Gas density at a specific temperature (i) and pressure (j)

 Density of water at reference temperature

 Density of a gas or fluid

 Density of a particle

 Standard deviation of particle mass distribution

 Kinematic viscosity
Abbrev.Unit

ACFM

Actual cubic feet per minute

atm

Atmosphere

BHP

Brake horsepower

Btu

British thermal unit

°C

Degree Celsius

cal

Calorie

cm

Centimeter

cp

Centipoise

DNm^{3}

Dry standard cubic meter

°F

Degree Fahrenheit

fpm

Feet per minute

ft

Foot

ft W.C.

Feet of water column

gal

Gallon

gm

Gram

gpm

Gallons per minute

gr

Grains

hp

Horsepower

in.

Inch

in. Hg

Inches of mercury

in. W.C.

Inches of water column

°K

Kelvin

kcal

Kilocalorie

kg

Kilogram

kPa

Kilopascal

L

Liter

lb

Pound

lb_{f}

Pounds force

lb_{m}

Pounds mass

m

Meter

mi

Mile

min

Minute

mm

Millimeter

mm Hg

Millimeter of mercury

M

Molarity

mPa

Millipascal

µg

Microgram

µm

Micrometer

Nm^{3}/min

Standard cubic meters per minute

nm

Nanometer

N

Normality

Pa

Pascal

p

Poise

ppm

Part per million

ppm(v/v)

(Also ppmv) Part per million calculated as a ratio of the volume of the pollutant divided by the total volume of the sample

ppmvd

Part per million (dry basis)

ppm(w/w)

Part per million calculated as a ratio of the weight of the pollutant divided by the total weight of the sample

psi

Pounds per square inch

psia

Pounds per square inch (absolute)

psig

Pounds per square inch (gauge)

°R

Degree Rankine

rpm

Revolutions per minute

SCFM

Standard cubic feet per minute

sec

Second