&EPA
United States
Environmental Protection
Agency
EPA-600/R-05/066
March 2005
Program PARAMS User's
Guide
Program Version: 1.0
Document Version: 1.0
•I" Diffusivity in Solids for Mixed Chemical Classes
Correlation
DS=A-B/H(V)
where Df = difiusivity in solid (rrf/s),
v = molar volume (g/mol), and
A and B are constants.
Material
-1.536 -4.674 0.997
Oriented strand board 19.73 -8.401 0.973
Particle board 10.59 -6.970 0.785
Plywood -0.6787 -4.720 0.815
Vinyl tile
•3.546
•4.286
0.917
Click on a material to select
-
Your selection
Gypsum board
Enter molar volume (cm3/mol)
i Copy
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EPA-600/R-05/066
March 2005
Program PARAMS
User's Guide
Program Version: 1.0
Document Version: 1.0
by
Zhishi Quo
U.S. Environmental Protection Agency
Office of Research & Development
National Risk Management Research Laboratory
Air Pollution Prevention & Control Division
Research Triangle Park, NC 27711
U.S. Environmental Protection Agency
Office of Research and Development
Washington, DC 20460
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Abstract
This Microsoft Windows-based computer program implements 30 methods for estimating the
parameters in indoor emissions source models, which are an essential component of indoor air
quality (IAQ) and exposure models. These methods fall into eight categories: (1) the properties
of indoor air, (2) the first-order decay rate constants for solvent emissions from indoor coating
materials, (3) gas-phase, liquid-phase, and overall mass transfer coefficients, (4) molar volume,
(5) molecular diffusivity in air, liquid, and solid materials, (6) solid-air partition coefficient, (7)
vapor pressure and volatility for pure organic compounds and petroleum-based solvents, and
(8) the properties of water. Potential users include those who develop or use IAQ and exposure
models and those who develop or use quantitative structure-activity relationship (QSAR)
models. In addition, many calculations are useful to researchers in areas other than indoor air
quality. Users can benefit from this program in two ways: first, it serves as a handy tool by
putting commonly used parameter estimation methods in one place; second, it saves users time
by taking over tedious calculations. It should be pointed out, however, that the methods
implemented in this program cover only a fraction of the parameters that appear in the more
than 50 indoor emission source models. Furthermore, the methods in the current version are
mostly for gaseous pollutants; those for particulate matter are not included.
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting
the Nation's land, air, and water resources. Under a mandate of national environmental laws,
the Agency strives to formulate and implement actions leading to a compatible balance
between human activities and the ability of natural systems to support and nurture life. To meet
this mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage
our ecological resources wisely, understand how pollutants affect our health, and prevent or
reduce environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention and control of
pollution to air, land, water, and subsurface resources; protection of water quality in public
water systems; remediation of contaminated sites, sediments and ground water; prevention
and control of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with
both public and private sector partners to foster technologies that reduce the cost of
compliance and to anticipate emerging problems. NRMRL's research provides solutions to
environmental problems by: developing and promoting technologies that protect and improve
the environment; advancing scientific and engineering information to support regulatory and
policy decisions; and providing the technical support and information transfer to ensure
implementation of environmental regulations and strategies at the national, state, and
community levels.
This publication has been produced as part of the Laboratory's strategic long-term research
plan. It is published and made available by EPA's Office of Research and Development to
assist the user community and to link researchers with their clients.
Sally Gutierrez, Acting Director
National Risk Management Research Laboratory
in
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EPA Review Notice
This report has been peer and administratively reviewed by the U.S. Environmental
Protection Agency and approved for publication. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia 22161.
IV
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Table of Contents
Section Page
Abstract ii
List of Figures vii
List of Tables viii
1. Introduction 1
1.1 Purpose and Intended Users 1
1.2 Limitations 1
1.3 Parameter Estimation Methods Implemented 1
2. Installation and Technical Support 3
2.1 Minimum System Requirements 3
2.2 Installing PARAMS from Compact Disk 3
2.3 Installing PARAMS from Zip File 3
2.4 Installation Problems 3
2.5 Viewing and Printing the User's Guide 4
2.6 Technical Support 4
3. A Brief Tour of the Program 5
3.1 User Interface 5
3.2 Example 1: Calculating the density of air at 23 °C, 1 atm, and 65% RH 5
3.3 Example 2: Calculating the gas-phase mass transfer coefficient
for n-decane (C10H22) at 23 °C and 50% RH 6
4. Method Descriptions 9
4.1 Properties of Air 9
4.1.1 Density of Dry and Moist Air 9
4.1.2 Moisture Content in Air 9
4.1.3 Viscosity of Air 10
4.2 First-Order Decay Rate Constant for Emissions from Paint 10
4.2.1 Methods for Petroleum-Based Paint 11
4.2.2 Methods for Latex Paint 14
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Table of Contents (concluded)
Section Page
4.3 Mass Transfer Coefficient 15
4.3.1 Gas-Phase Mass Transfer Coefficient 15
4.3.2 Liquid-Phase Mass Transfer Coefficient 17
4.3.3 Overall Mass Transfer Coefficient 18
4.4 Molar Volume 19
4.4.1 Atomic and Structural Diffusion Volume Increments 20
4.4.2 Le Bas Molar Volume 20
4.5 Molecular Diffusivity 21
4.5.1 Diffusivity in Air 21
4.5.2 Diffusivity in Water 22
4.5.3 Diffusivity in Solids as a Function of Molecular Weight 24
4.5.4 Diffusivity in Solids as a Function of Molar Volume 24
4.6 Solid-air Partition Coefficient 26
4.6.1 Material and Chemical Specific Methods 26
4.6.2 Method for All Materials and Compound Classes 27
4.7 Volatility of Organic Compounds 27
4.7.1 Makar Method for Pure Organic Compounds 28
4.7.2 Total Vapor Pressure of Petroleum-Based Solvents 29
4.8 Properties of Water 29
4.8.1 Vapor Pressure of Water 29
4.8.2 Viscosity of Liquid Water 30
References 31
VI
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List of Figures
1 Error Message Encountered When Trying to Install PARAMS to a
Network Computer with Security Restrictions 3
2 Layout of Params' Main Screen, No Selected Method 5
3 Layout of the Main Window after the Method for Air Density Is Selected 6
4 Calculation Screen for Air Density 7
5 Calculation Screen for Gas-Phase Mass Transfer Coefficient Based on Sherwood
Number. The Arrow Points to the Built-in Calculator for Air Density 7
6 Calculation Screen for Diffusivity in Air (FSG Method 1) 8
7 Calculation Screen for Moisture Content in Air 10
8 Calculation Screen for Air Viscosity 11
9 Calculation Screen for First-Order Decay Rate Constant with the Chinn Method . . 12
10 Calculation Screen for First-order Decay Rate Constant for TVOC Emissions
from Oil-Based Indoor Coating Materials 13
11 Calculation Screen for k and E for Emissions of Individual VOCs from
Oil-Based Coating Materials 14
12 Calculation Screen for Estimating the First-Order Decay Rate Constant for VOC
Emissions from Alkyd Paint with the Koontz Method 15
13 Calculation Screens for Estimating the First-Order Decay Rate Constants for
VOC Emissions Form Latex Paint. The Screen on Top Is for k, and the
One on Bottom for k2 16
14 Calculation Screen for Gas-Phase Mass Transfer Coefficient 16
15 Calculation Screen for Liquid-Phase Mass Transfer Coefficient for Still Water .... 18
16 Calculation Screen for Liquid-Phase Mass Transfer Coefficient for Moving Water . 18
17 Calculation Screen for Overall Gas- and Liquid-Phase Mass Transfer Coefficients . 19
18 Calculation Screen for Overall Gas- and Liquid-Phase Mass Transfer
Coefficients for Still Water Pools and Films 20
19 Calculation Screen for Molar Volume Based on Atomic and Structural Diffusion
Volume Increments 21
20 Calculation Screen for Le Bas Volume 22
21 Calculation Screen for Diffusivity in Air with FSG Method 1, in Which the Molar
Volume Is Estimated from Atomic and Structure Diffusion Volume Increments ... 23
vii
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List of Figures (concluded)
Figure Page
22 Calculation Screen for Diffusivity in Air with the FSG Method, in Which the Molar
Volume Is Estimated from the Le Bas Volume 23
23 Calculation Screen for Molecular Diffusivity in Air with the WL Method 24
24 Calculation Screen for Molecular Diffusivity in Water 25
25 Calculation Screen for Diffusivity in Solid Material. This Method Is Specific
to Given Material/Chemical Class Combinations 25
26 Calculation Screen for Molecular Diffusivity in Solid Materials. This Method
Is Not Specific to a Particular Compound Class 26
27 Calculation Screen for Solid-air Partition Coefficient. This Method Is
Material and Chemical Specific 27
28 Calculation Screen for Solid-air Partition Coefficient. This Method Is Not
Specific to Compound Classes 27
29 Calculation Screen for Estimating the Vapor Pressure Based on Compound Class . 28
30 Calculation Screen for Total Vapor Pressure of Petroleum-Based Solvents 29
31 Calculation Screen for Water Vapor Pressure 30
32 Calculation Screen for Water Viscosity 30
List of Tables
Table Page
1 List of Parameter Estimation Methods in PARAMS 2
2 Absolute Viscosity of Air from the Literature 10
Vlll
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1. Introduction
1.1 Purpose and Intended Users
Although over 50 indoor emission source models
have been developed (Guo, 2002a), few are widely
used in indoor exposure assessment. This imbalance
is partially caused by the fact that many source
models contain one or more parameters that are
difficult to determine. This program is a step toward
alleviating this problem by providing 30 methods for
estimating some of the parameters in those source
models. It is useful to those who develop or use
indoor air quality (IAQ) and exposure models, and
those who develop or use quantitative structure-
activity relationship (QSAR) models. In addition,
many methods in this program are useful to research-
ers in areas other than indoor air quality. Users can
benefit from this program in two ways: (1) it serves
as a handy tool by putting commonly used methods
in one place, and (2) it saves users' time by taking
over tedious calculations.
This program was developed based on the devel-
oper's review of existing parameter estimation
methods for indoor emission source models (Guo,
2002b). Users are encouraged to read the review
article for more detailed discussions and, more
importantly, to consult with the original references.
The name of this program, PARAMS, is an abbrevia-
tion of parameters.
1.2 Limitations
Overall, development of parameter estimation meth-
ods has not progressed to the extent that IAQ model-
ers would like to see. Users are reminded that the
number of parameters that can be estimated with this
program is only a fraction of the total number of
parameters in the existing indoor source models.
This program is intended to supplement, not to
substitute for, experimentally determined model
parameters. In other words, this program is most
useful when experimentally determined values are
not available.
Most methods implemented in this program are for
gaseous pollutants. Methods for particulate matter are
not included in the current version.
1.3 Parameter Estimation Methods
Implemented
The methods implemented in this program are sum-
marized in Table 1. Detailed discussions on each
method is provided in Section 4. The References
section gives a complete list of sources of these
methods.
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Program PARAMS
Table 1. List of Parameter Estimation Methods in PARAMS.
Method Group Subgroup
Air properties
First-order decay rate constant
Mass transfer coefficient
Molar volume
Molecular diffusivity
Solid-air partition coefficient
Volatility
Water properties
Total
Density
Moisture content
Viscosity
Petroleum-based paint
Latex paint
Gas-phase
Liquid-phase
Overall
N/A
Gas-phase
Liquid-phase
Solid-phase
N/A
N/A
Vapor pressure
Viscosity
No. of methods
1
1
1
4
2
3
2
2
2
3
1
2
2
2
1
1
30
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User's Guide
2. Installation and Technical Support
2.1 Minimum System Requirements
• Intel Pentium 90 or equivalent,
• Microsoft Windows 95 or later (see Section
2.4 for details),
• 16 Mb of RAM,
• 10 Mb free hard disk space,
• CD-ROM drive (for installation from CD),
• Software WinZip (for installation from zip
file),
Software Acrobat Reader 4.0 or later (for
printing the User's Guide),
• VGA or higher resolution monitor, and
• Mouse or other pointing devices.
2.2 Installing PARAMS from Compact
Disk
• Insert the program CD;
• If the installation program does not start
automatically, use Windows Explorer to find
the CD-ROM drive, then click on file
Setup.EXE; and
• Follow instructions to complete installation.
2.3 Installing PARAMS from Zip File
• If you received the zip file as an e-mail at-
tachment, save the file (PARAMS.txt) to a
temporary folder in your hard drive;
• Rename the file PARAMS.zip;
• Unzip (i.e., extract) the zip file with WinZip
and run program Setup.EXE;
• Follow the instructions to complete installa-
tion; and
• Delete installation files.
2.4 Installation Problems
This program has been tested for installation errors
for Microsoft Windows 95, 98, 2000, ME, and XP
Professional. It is not guaranteed that it will work
under other versions of Windows. An independent
quality assurance (QA) review revealed that this
program could not be installed to Windows PC Home
Edition.
Also note that, if your computer has Windows XP
Professional and is connected to a network, you may
receive an error message similar to the one shown in
Figure 1. It means that you are not authorized to
install any software on your computer, and you must
ask a computer support technician to install the
software for you.
Setup has detected that unlnstall5hield is in use. Please close unlnstallShield and restart setup.
Error 432.
OK
Figure 1. Error Message Encountered When Trying to Install PARAMS
to a Network Computer with Security Restrictions.
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Program PARAMS
2.5 Viewing and Printing the User's
Guide
The User's Guide is provided in pdf file format, and
requires Adobe Acrobat Reader (version 4 or higher)
to read. There are two ways to access the document:
From Windows Start menu:
• Find the group name for program PARAMS
by clicking on , ,
Click on the group name (The default name is
"Params 1.0"),
• Click on "PARAMS Users Guide".
From the program CD:
• Place the program CD in the CD-ROM drive,
• Use the Windows Explorer to open folder
\Manual,
• Double click on filename "PARAMS Users
Guide.pdf".
2.6 Technical Support
For bug reporting, questions, comments, or sugges-
tions, please contact the developer at the following
address:
Dr. Zhishi Guo
U.S. EPA
Mail Code E305-03
Research Triangle Park, NC 27711
E-mail: guo.zhishi@epa.gov
Telephone: 919-541-0185
Fax: 919-541-2157
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User's Guide
3. A Brief Tour of the Program
3.1 User Interface
To start the program, choose Start Q> Programs Q>
Params 1.0 Q> Params. This program has a fairly
simple user interface. Figure 2 shows the main screen
after the user launches the program under Windows
XP. Note that, for other Windows operating systems,
the appearance of the start screen may be slightly
different. As shown in Figure 2, all the methods are
organized in a tree list, very similar to the file list in
Windows Explorer. To view more details in the list,
simply click one of the plus (+) signs. There are two
small buttons under the tree list. Clicking the one on
the left (with an open book icon) makes the tree list
fully expand; clicking the one on the right (with a
PARAMS -- Parameter Estimation for Indoor Source Models
closed book icon) makes the list collapse.
To select a parameter estimation method, click on one
of the items in the tree list. The method selected will
appear in the upper-right pane (Figure 3). The next
step is to click the button to perform the
calculation. Two examples are provided below.
3.2 Example 1: Calculating the density
of air at 23 °C, 1 atm, and 65% RH
Move cursor to the tree list; click on the plus(+) sign
in front of "Air properties" or double-click on "Air
properties"; then click on "density." After the item
you selected appears on the screen at the upper-right
Select .1 method
Your selection
+ jjal
E First-order decay rate constant
+ Mass transfer coefficient
+ Molar volume
El Molecular diffusivity
+ Solid/air partition coefficient
+ Volatility
+ Water properties
Figure 2. Layout of PARAMS' Main Screen, No Selected Method.
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Program PARAMS
• T PARAMS -- Parameter Estimation for Indoor Source Models
- n x
Select a method
moisture content
viscosity
+ First-order decay rate constant
+ Mass transfer coefficient
+ Molar volume
+ Molecular diffusivity
+ Solid/air partition coefficient
+ Volatility
+ Water properties
Your selection
Air properties
density
Figure 3. Layout of the Main Window after the Method for Air Density Is Selected.
corner (see Figure 3), click on the button to
open the calculation sheet. Note that PARAMS can
compute the density for either dry or wet air, and that
the default setting is for dry air. To switch to moist
air, select "moist air" from below the temperature
entry box. Change the temperature to 23; adjust the
RH value to 65; and, finally, click the
button. The result should be 0.0011843 g/cm3 (See
Figure 4). If you would like to use the result in a
different application (such as a spreadsheet), click the
button to copy the result to Windows clip-
board. You can latter paste the result to the applica-
tion. Use of the button, which is
dimmed in Figure 4, will be explained in the next
example.
3.3 Example 2: Calculating the Gas-
Phase Mass Transfer Coefficient for n-
Decane (C10H22) at 23 °C and 50% RH
from Sherwood Number
From the tree list, select "Mass transfer coefficient"
-> "gas phase" -> "from Sherwood number;" click
the button to display the calculation screen
(Figure 5).
This method requires five parameters: (1) density of
air, (2) viscosity of air, (3) velocity of air in the room,
(4) diffusivity of the compound in room air, and (5)
characteristic length of the source. If you know all of
their values, you can enter them manually. You can
also use the built-in calculators for air density and
viscosity and for diffusivity of the compound. In
other words, you can calculate these values without
leaving the program.
To calculate the density of air, click the calculator
button next to the entry box; the calculation screen
for air density will appear (see Figure 4); enter or
adjust the required parameters; click the
button; then click the button to paste
the result to the calculation screen for the gas-phase
mass transfer coefficient.
-------
User's Guide
••" Air density
Air Temperature
|23
Atmospheric Pressure
mmHg
Relative Humidity (RH)
lelect one:
Dry air
0 Moist air
Air density = 0.0011843 (g/cnf)
? Help [BlCJjculate]] H^j Copy
Figure 4. Calculation Screen for Air Density.
Density of air (g/cm3)
Viscosity of air (g/cm/s)
Velocity of air (cm/s)
Diffusivity in air (:ms/s)
Characteristic length (cm)
Close
•r Gas-phase Mass Transfer Coefficient (kg) from Sherwood Number
Help
/ Paste & Exit | H^ Copy
Figure 5. Calculation Screen for Gas-Phase Mass Transfer Coefficient Based on
Sherwood Number. The Arrow Points to the Built-in Calculator for Air
Density.
7
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Program PARAMS
Similarly, you can calculate the viscosity of air by
clicking on the second calculator button.
Air velocity inside a room varies from case to case.
For this exercise, enter 5. For hints, click the button
with a question mark. It will tell you that the typical
range air velocity in the indoor environments is from
5 to 10 cm/s.
To calculate the diffusivity of n-decane in air, click
the calculator button next to the entry box for diffus-
ivity; the program will ask you to select one from
three available methods. If you are unfamiliar with
these methods, click on the button. For this
practice, select FSG method 1. In the calculation
screen for diffusivity in air, enter the molecular
formula for n-decane by changing the carbon number
to 10 and hydrogen number to 22; click the button; then click the button
(Figure 6).
Characteristic length is a measure of source size. For
this exercise, enter 20. Note that hints are available
for this input parameter.
Finally click the button to get the result.
•F Diffusivity in Air -- FSG Method (1)
Chemical Formula & Structure
Carbon (C)
Hydrogen (H)
Oxygen (0)
Nitrogen (N)
Chlorine (Cl)
Sulfur (S)
Rings *
10
C10 H22
Temperature (°C)
Pressure (atm) h g
' Including aromatic and heterocyclic rings.
Help
Paste & Exit li^q Copy
Figure 6. Calculation Screen for Diffusivity in Air (FSG Method 1).
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User's Guide
4. Method Descriptions
4.1 Properties of Air
The properties of air calculated by this program are
density, moisture content, and viscosity.
4.1.1 Density of Dry and Moist Air
The density of dry or moist air is calculated from
Equations. 1 and 2 (Weast, 1973, page F-9), respec-
tively.
RH
T, P - 0.3783 Pw
0 ji p
(1)
(2)
where ddry = density of dry air at temperature T and
pressure P, in grams per cubic meter,
dmoisi = density of moist air at temperature T
and pressure P, in grams per cubic
meter,
d0 = density of dry air at temperature T0 and
pressure P0, in grams per cubic meter,
T0 = standard temperature = 273.2 K,
T = temperature of air in Kelvin,
P0 = standard atmospheric pressure = 760
mm Hg,
P = atmospheric pressure in millimeters
mercury (Hg), and
pw = partial pressure of moisture in air in
millimeters Hg.
In this program, d0 = 0.0012929 g/cm3 at 0 °C and
760 mmHg is from Weast (1973, page F-9).
The user input for moisture content is in relative
humidity, which is then converted to partial pressure
(millimeters Hg) by using Equation 3.
(3)
where RH = relative humidity, and
Pw0 = water vapor pressure at given temp-
erature in millimeters Hg.
The method used to estimate the water vapor pressure
(Pw0) is described in Section 4.8.1. The calculation
screen is shown in Figure 4 in the previous section.
4.1.2 Moisture Content in Air
This program computes the moisture content in room
air—either saturated or unsaturated—in parts per
million and grams per cubic meter. Information
required from the user includes room temperature,
atmospheric pressure, and for unsaturated air, relative
humidity. Figure 7 shows the calculation screen.
Calculation of moisture content in air involves three
steps:
Step 1: Calculating water vapor pressure by using
Equation 44 in Section 4.8.1;
Step 2: Calculating the partial pressure by using
Equations;
Step 3: Converting partial pressure to concentration
units by Equations 4 and 5.
C = 106 P IP
^wl 1U J w ' J 0
(4)
where Cw] = water content in air in parts per million,
P0 = atmospheric pressure in millimeters Hg.
where Cw2 is in grams per cubic meter,
-------
Program PARAMS
• I' Moisture content in air
-Air Temperature
Atmospheric Pressure
mmH9
Relative Humidity (RH)
oo
lelect one:—
9 Saturated
isaturated
Help
Calculate
JL Close
Figure 7. Calculation Screen for Moisture Content in Air.
Mw = molecular weight for water in grams per
mole,
VT = molar volume of gas at temperature T in
liters.
4.1.3 Viscosity of Air
This program calculates the absolute viscosity of air
between 0 and 74 °C by using experimental data
found in the literature. Figure 8 shows the calculation
screen, and Table 2 the viscosity data.
Table 2. Absolute Viscosity of Airfrom the Litera-
ture3
Temperature
Viscosity
(°Q
0
18
40
54
74
(l^Poise)
170.8
182.7
190.4
195.8
210.2
(g/s/cm)
1.708xlQ-4
1.827xlQ-4
1.904xlQ-4
1.958xlQ-4
2.102xlO-4
1 Source: Weast, 1973; page F-43.
A third-order polynomial (Equation 6) is used to
calculate the viscosity at any temperature between 0
and 74 °C under the standard atmospheric pressure.
The coefficients in Equation 6 were determined by
least square with r2 = 0.999999998, where r is the
correlation coefficient.
//= 170.80
1.60383
0.9154397-0.0170441
lO-4P
(6)
where //= absolute viscosity in microPoise (1 Poise
= 1 gram per centimeters per second),
and
T= temperature in degrees Celsius.
Note that some indoor source models require kine-
matic viscosity, which is the ratio of the absolute
viscosity and air density. Kinematic viscosity has the
unit of Stokes or, equivalently, square centimeters per
second.
4.2 First-Order Decay Rate Constant
for Emissions from Paint
The software contains methods for calculating the
first-order decay rate constant for both latex and
petroleum-based paints. The decay rate constant for
petroleum-based paint can be calculated by four
methods.
10
-------
User's Guide
"I* Absolute viscosity of air
- n x
Enter air temperature (°C):
i
g Calculate I
Figure 8. Calculation Screen for Air Viscosity.
4.2.1 Methods for Petroleum-Based Paint
The first-order decay emission model has two forms
(Equation 7), and they are equivalent because of the
relationship in Equation 8 (Guo, 2000a).
InlO
I k
(7)
(8)
where E = emission factor in milligrams per square
meter per hour,
E0 = initial emission rate in milligrams per
square meter per hour,
M0 = initial pollutant mass in the source in
milligrams per square meter,
k = first-order decay rate constant (h"1), and
t = time in hours.
When the initial pollutant mass (M0) is known, the
decay constant (K) becomes the only parameter to be
determined, and this program provides four methods
for estimating k for emissions of volatile organic
compounds (VOCs) and total VOCs (TVOCs) from
petroleum-based paint. These methods are the Chinn-
Evans and Guo methods for TVOCs and the Guo and
Koontz methods for individual VOCs.
Chirm-Evans Method
Evans (1994) proposed to estimate k from the 90%
drying time (t09) for solvent evaporations from
petroleum-based paint (Equation 9).
(9)
10.9
where tog is calculated from Equations 10 and 11
(Chinn, 1981).
C =
= 7.3698-0.95461og10C
\6040mP
T
(10)
(11)
where Cv = solvent volatility in milligrams per cubic
meter,
m = molecular weight of solvent in grams per
mole,
P = vapor pressure of solvent in millimeters
Hg, and
T= temperature in Kelvin.
Input parameters include vapor pressure, molecular
weight, and temperature. Built-in calculators are
available for the first two parameters (Figure 9). If
this method is used to estimate & for TVOC emissions
for a solvent mixture, parameter P in Equation 11
should be replaced by the total vapor pressure for the
solvent. The total vapor pressure can be (1) experi-
mentally determined, (2) estimated based on the
contents of the major VOCs (see Section 4.7.2), or
(3) approximated by the vapor pressure of the most
abundant VOC in the mixture—a calculator is avail-
11
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Program PARAMS
•T First-order decay rate constant from 90% drying time
f- Ifnlfxl
Enter parameters here
Vapor pressure (mm Hg)
molecular weight (g/mol)
E = EO exp(-k t)
Pastel Exit lift Copy
Figure 9. Calculation Screen for First-Order Decay Rate Constant with
the Chinn Method.
ble in the data entry window. The average molecular
weight for TVOCs can be (1) estimated based on the
contents of the major VOCs (see Section 4.7.2) or (2)
approximated by the molecular weight of the most
abundant VOC in the mixture.
This method tends to overestimate & for an individual
VOC in a mixture. One should also be aware that the
correlation (Equation 10) was found with the 90%
evaporation time being determined on paper filters
with dry air flowing through (ASTM, 1977). Appar-
ently, the experimental conditions (e.g., film thick-
ness and ventilation rate) are far from realistic.
Besides, this method ignores the effect of film thick-
ness. Despite these limitations, it is very useful for
rough estimations because all the parameters in
Equations. 10 and 11 are easily obtained.
Guo Methodfor TVOCs
This method (Equation 12) was obtained by simplify-
ing a mass transfer model (Guo, 1999). It also pro-
vides an estimate of the initial emission factor (Equa-
tion 13). Information required from the user is shown
in Figure 10.
/C \^- f
k =
9dy
F = k C
j^0 n. \^T
(12)
(13)
where kis in h"1,
kg = gas-phase mass transfer coefficient in
meters per hour,
Cr = TVOC saturation concentration con-
verted from total vapor pressure in milli-
grams per cubic meter,
6= thickness of paint film in meters,
d= density of paint in grams per cubic meter,
yr = TVOC content in paint in milligrams per
gram, and
12
-------
User's Guide
•I* 1st-order decay constant for TVOC in oil-based paint
Total vapor pressure for TVOC (mm Hg)
Solvent average molecular wt (g/mol)
Wet paint film thickness (urn)
Paint density (g/crri5)
Gas-phase mass transfer coef (rn/h)
TVOC content in paint (mg/g)
7 Help
Model: E = EO exp(-k t)
Copy
Figure 10. Calculation Screen for First-order Decay Rate Constant for
TVOC Emissions from Oil-Based Indoor Coating Materials.
E0 = initial emission factor in milligrams per
square meter per hour.
If the user calculates the mass transfer coefficient
(kg), the molecular formula of the most abundant
component in the solvent should be used. As previ-
ously described, the total vapor pressure (Cr) can be
(1) experimentally determined, (2) estimated based
on the contents of the major VOCs (see Section
4.7.2), or (3) approximated by the vapor pressure of
the most abundant VOC in the mixture. The calcula-
tor button next to the total vapor pressure in the data
entry window is for option (2). The method described
in Section 4.7.1 can be used for option (3)
Guo Method for Individual VOCs
Equations 14 and 15 (Guo, 1999) are used to estimate
the first-order decay rate constant (K) and the initial
emission rate (Eg) for individual VOCs from oil-
based indoor coating materials. Seven input parame-
ters are required from the user (Figure 11).
K „ U,, fflT
9d yT mi
, „ y,mr
(14)
(15)
s yTm,
where A: is in hr"1,
Cv = VOC saturation concentration converted
from vapor pressure in milligrams per
cubic meter,
yt = VOC content of the paint in milligrams
per gram,
mr = average molecular weight for TVOCs
in grams per mole, and
mt = molecular weight for the VOC of interest
in grams per mole.
Koontz Method for Individual VOCs
The Koontz correlation (Equation 16) was found
13
-------
Program PARAMS
•" 1st-order decay constant for individual VOC in oil-based paint
VOC vapor pressure (mm Hg)
Solvent average molecular wt (g/mol)
Wet paint film thickness (urn)
Paint density (g/crri5)
Gas-phase mass transfer coef (rn/h)
TVOC content in paint (mg/g)
VOC content in paint (mg/g)
7 Help
JJ
Model: E = EO exp(-k t)
@S Copy
Close
Figure 11. Calculation Screen for /rand Efor Emissions of Individual
VOCs from Oil-Based Coating Materials.
from experimentally determined k's for alkyd paint
(Koontz, 2001),
pO.27
'" " 06)
k= 2.95 xlO9
,4.02 ,30.58
; (rz = 0.86)
m
where k is in h"1,
P = vapor pressure in millimeters Hg,
m = molecular weight in grams per mole,
6= thickness of paint film in mils, and
r = correlation coefficient.
User inputs are vapor pressure, molecular weight, and
wet film thickness (Figure 12).
4.2.2 Methods for Latex Paint
The dual exponential decay model (Equation 17) is
often used for glycol emissions from latex paint.
Wilkes, et al. (1996) proposed Equations 18 and 19
for estimating ^ and k2, respectively. This method
does not estimate E1 and E2.
T^ T^ — K i t i T^ — K o t
fa — fa £ ~\~ fa Q
£1 = 233.25 P; (r2 = 0.92)
k2 = 5.839 x 10'X (r2 = 0.96)
(17)
(18)
(19)
where E, = initial emission factor for "fast" emis-
sions in milligrams per square meter per
hour,
E2 = initial emission factor for "slow" emis-
sions in milligrams per square meter per
hour,
kj = first-order decay rate constant for "fast"
emissions (h"1),
k2 = first-order decay rate constant for "slow"
emissions (h"1),
P = vapor pressure in millimeters Hg,
m = molecular weight in grams per mole, and
r = correlation coefficient.
14
-------
User's Guide
•" 1st-order decay constant for VOC from alkyd paint
f- Ifnlfxl
Vapor pressure (mm Hg)
Molecular wight (g/mol)
Wet film thickness
Model: E = EO exp(-k t)
Figure 12. Calculation Screen for Estimating the First-Order Decay
Rate Constant for VOC Emissions from Alkyd Paint with the
Koontz Method.
hese two parameters are calculated with two separate
calculation screens (Figure 13).
4.3 Mass Transfer Coefficient
The software can calculate the gas-phase mass
transfer coefficient by either the Sherwood, the
Sparks, or the Mackay-Matsugu method. The liquid-
phase mass transfer coefficient can be calculated
either for still water pools and films or for moving
water. The overall mass transfer coefficient can be
calculated on a generic basis or for still water pools
and films.
4.3.1 Gas-Phase Mass Transfer Coefficient
Three methods are provided for calculating the gas-
phase mass transfer coefficient: Sherwood method,
Sparks method, and Mackay-Matsugu method. Since
all three methods require the same user input, they
share the same calculation screen (Figure 14).
Sherwood Method
This method (Bennet and Myers, 1982) is based on
correlations between three dimensionless numbers:
Sherwood number (Sh), Schmidt number (Sc\ and
Reynolds number (Re).
k L
Sh=-— (20)
Lup
S =
(21)
(22)
where kg = gas-phase mass transfer coefficient in
meters per hour,
L = characteristic length of the source in
meters,
15
-------
Program PARAMS
1st-order constant for latex paint (k1)
Enter vapor pressure (mm Hg):
- n x
E = E1*exp(-k1 t) + E2*exp(-k21)
H Calculate I
I* 1st-order constant for latex paint (k2)
Enter molecular weight (g/mol):
E = E1*exp(-k1 t) + E2*exp(-k21)
Figure 13. Calculation Screens for Estimating the First-Order Decay
Rate Constants for VOC Emissions From Latex Paint. The
Screen on Top Is for ^ and the One on Bottom for k2.
•r Gas-phase Mass Transfer Coefficient (kg) from Sherwood Number
Density of air (g/crn3)
i
Viscosity of air (g/cm/s)
Velocity of air (cm/s)
Diffusivity in air (crrvVs)
Characteristic length (cm)
Help
X Close I
^^^^^^^^•^^^^^^J .^^^^^.^^^^^J 1
Figure 14. Calculation Screen for Gas-Phase Mass Transfer
Coefficient.
16
-------
User's Guide
Da = diffusivity in air in square meters per
hour,
u = air velocity in meters per hour,
p = density of air in grams per cubic meter,
and
// = viscosity of air in grams per meter per
hour.
A series of correlations have been developed between
Sh, Sc, andRe (Bennett & Myers, 1982; White, 1991).
For example, Equation 23 applies to laminar flow
conditions and is used in this program.
(23)
The calculation involves four steps.
Step 1. Calculate the Reynolds number (Equation
21);
Step 2. Calculate the Schmidt number (Equation 22);
Step 3. Calculate the Sherwood number (Equation
23); and
Step 4. Calculate the gas-phase mass transfer coeffi-
cient (k) from Equation 20.
Sparks Method
Sparks, etal (1996) proposed a simpler method based
on experimental data obtained from small chambers
and a test house (Equation 24), and is used in several
emission source models for interior paint.
£„ = 0.33 D L'1 RJ
(24)
Mackay-Matsugu Method
This method was based on experimental data for
water evaporation (Mackay and Matsugu, 1973) and
has been used mostly for solvent spills.
0.78 r-0.11 o -0.67
k - 0.0292 Ma/8rau S
(25)
where kg, u, and L are in meters per hour, meters per
hour, and meters, respectively.
These three methods require the same user input.
Currently there are not sufficient experimental data to
discriminate one method from the others. This devel-
oper suggests the following "rules-of-thumb" for
method selection: (1) choose the method that is
recommended by the source model; (2) if the source
model does not recommend a specific method, use
the Sherwood method.
4.3.2 Liquid-Phase Mass Transfer Coefficient
The software can calculate the liquid-phase mass
transfer coefficient for still water pools and films and
for moving water.
Still Water Pools and Films
For still, shallow water pools and films, Guo and
Roache (2003) proposed to use Equation 26 to
estimate the liquid-phase mass transfer coefficient.
(26)
where kL(X) = liquid-phase mass transfer coefficient
for compound X in meters per hour,
DL(X) = diffusivity of compound X in water
in square meters per hour.
A calculator is provided in the calculation screen for
the diffusivity in water (Figure 15), and the method is
discussed in Section 4.5.2.
Moving Water
This method (Equation 27) is for ambient water
bodies (Southworth, 1992) and is included in this
program because there are no similar methods for
indoor conditions. User inputs are molecular weight,
velocity of water flow, and water depth (Figure 16.).
Use this method with caution.
(27)
where kL is in centimeters per hour,
uc = velocity of water current in meters per
second,
Z = water depth in meters, and
m = molecular weight in grams per mole.
17
-------
Program PARAMS
• r Liquid-phase Mass Transfer Coefficient for Still Water (kL)
Enter diffusivity in water (mz/h):
i- n x
I
Calculate I
Figure 15. Calculation Screen for Liquid-Phase Mass Transfer Coefficient
for Still Water.
•r Liquid-phase mass transfer coeff. for flowing water
Enter parameters here
Molecular weight (g/mol)
Water flow velocity (m/s)
Figure 16. Calculation Screen for Liquid-Phase Mass Transfer
Coefficient for Moving Water.
4.3.3 Overall Mass Transfer Coefficient
Generic
Overall mass transfer coefficients are often used to
estimate pollutant emissions from tap water and
water-based consumer products. This generic method
(Equations 28 and 29) is not a parameter estimation
method per se. Rather, it gives the definition of
overall mass transfer coefficient (Lyman, etal., 1990;
ch 15, pi 1) and is used to calculate the overall mass
18
-------
User's Guide
transfer coefficient from the gas- and liquid-phase
mass transfer coefficients and Henry's constant.
Figure 17 shows the calculation screen.
1
K.
OL
1
H
1
kgH
k
(28)
(29)
where KOL = overall liquid-phase mass transfer
coefficient in meters per hour,
kL = liquid-phase mass transfer coefficient in
meters per hour,
kg = gas-phase mass transfer coefficient in
meters per hour,
H= dimensionless Henry's constant (i.e.,
air/water partition coefficient).
Since the two overall mass transfer coefficients (KOL
and KOG) are linked by Equation 30, one can be
calculated from the other.
(30)
Still Water Pools and Films
For still water pools and films, Guo and Roache
(2003) proposed a three-step calculation method.
Step 1. Use Equation 20 to estimate the gas-phase
mass transfer coefficient (&g);
Step 2. Use Equation 27 to estimate the liquid-phase
mass transfer coefficient (kL); and
Step 3. Use Equation 28 to calculate the liquid-phase
overall mass transfer coefficient.
Once the overall liquid-phase mass transfer coeffi-
cient (KOI) is known, the overall gas-phase mass
transfer coefficient (KOG) can be easily obtained from
Equation 30. Calculators for kg and kL are provided in
the calculation screen (Figure 18).
4.4 Molar Volume
Molar volume (often in cubic centimeters per mole)
is a measure of molecular size and is used to estimate
«r Overall mass transfer coeff. (generic method)
\- Ifnlfxl
Gas-phase mass transfer coeff. (m/h)
Liquid-phase mass transfer coeff. (m/h)
r
Dimensionless Henry's constant (air/water)
I
® Convert |
7 Help
Epi Copy
X Close |
Figure 17. Calculation Screen for Overall Gas- and Liquid-Phase Mass
Transfer Coefficients.
19
-------
Program PARAMS
«T Overall mass transfer coeff. for still water
Gas-phase mass transfer coeff. (m/h)
Diffusivity in water (m3/h)
Dimensionless Henry's constant (air/water)
I
® Convert |
7 Help
Figure 18. Calculation Screen for Overall Gas- and Liquid-Phase Mass
Transfer Coefficients for Still Water Pools and Films.
the diffusion coefficient in air, water, and solids. Two
methods are commonly used. One is based on atomic
and structural diffusion volume increments and the
other is known as the Le Bas molar volume, which is
determined at the normal boiling point of the sub-
stance. The relationship between these two parame-
ters is shown in Equation 31.
LB
(31)
where Vmol = molar volume of gas at normal temper-
ature in cubic centimeters per mole, and
VLB = Le Bas molar volume in cubic centi-
meters per mole.
4.4.1 A tomic and Structural Diffusion Volume
Increments
In this method, the molar volume is the sum of the
volume for each atom and structure (Fuller, et al.,
1966). The data table used in this program is from
Lyman, et al.(1990, ch 17, p 11). For instance, the
diffusion volume increments for carbon, hydrogen,
and the aromatic ring are, respectively, 16.5, 1.98,
and -20.2 cmVmol. Thus, the molar volume for
benzene (C6 H6) is
Vmol = 6x16.5 + 6x 1.98 - 20.2 =110.9 (cmVmol)
The drawback of this method is that the incremental
molar volumes are only available for six atoms: C, H,
O, N, Cl, and S. Furthermore, the values for N, Cl,
and S are based on limited experimental data. The
calculation screen for this method is shown in Figure
19.
4.4.2 Le Bas Molar Volume
The Le Bas method estimates the molar volumes of
liquids at their respective normal boiling points. Like
the method described above, the Le Bas volume is
also additive. The original data table is used in this
program (Reid, et al., 1977 p 58; Lyman, et al., 1990,
ch 17, p 11). This method pays more attention to the
molecular structure than the previous method (Sec-
tion 4.4.2). For instance, oxygen has five incremental
20
-------
User's Guide
•' Diffusion Volume
f- Ifnlfxl
Chemical Formula & Structure
Carbon (C)
Hydrogen (H)
Oxygen (0)
Nitrogen (N)
Chlorine (Cl)
Sulfur (S)
Rings *
* Including aromatic and heterocyclic rings.
? Help
Paste &Exit
18 Copy
X Close
Figure 19. Calculation Screen for Molar Volume Based on Atomic and
Structural Diffusion Volume Increments.
volumes depending on its bonding with other atoms
(e.g., esters and acids). Incremental volumes are
available for nine atoms: C, H, O, N, Br, Cl, F, I, and
S . The calculation screen is shown in Figure 20.
4.5 Molecular Diffusivity
The software contains algorithms for calculating
diffusivity in solids as a function of either molecular
weight or molar volume, in water, and in air by two
methods.
4.5.1 Diffusivity in Air
The method of Fuller-Schettler-Giddings (FSG) and
the method of Wilke and Lee (WL) are the two most
commonly used methods for estimating molecular
diffusivity in air. Overall, the WL method is more
accurate, but requires knowledge of the boiling point
of the chemical of interest.
FSG method
This method is based on Equation 32 (Fuller, et al.,
1966). It is most accurate for non-polar gases at low
to moderate temperature and is less accurate for the
polar acids and glycols.
il.75
MAMB
(32)
(33)
where DA = molecular diffusivity in square centi-
meters per second,
T= temperature in Kelvin,
MA = molecular weight for air = 28.97 g/mole,
MB = molecular weight for the chemical of
interest in grams per mole,
P = atmospheric pressure in atmospheres,
21
-------
Program PARAMS
•r Le Bas Molar Volume
Chemical Formula & Structure
Carbon (C)
Hydrogen (H)
Oxygen (0), except below
0 in methyl esters/ethers
0 in ethyl esters/ethers
0 in higher estersfethers
0 in acids
0 joined to S, P, S
Nitrogen (N), double bound
Nitrogen (N), primary amines
Nitrogene (N), 2nd amines
n
jo :]
[5 ^j
B ^J
B ^j
Bromine (Br)
Chlorine (Cl)
Fluorine (F)
Iodine (I)
Sulfur (S)
3-membered ring
4-membered ring
5-membered ring
6-membered ring
Naphthalene
Anthracene
Help
S; Paste & Exit
Figure 20. Calculation Screen for Le Bas Volume.
VA = molar volume for air (20.1 cmVmol),
and
VB = molar volume for the chemical of interest
in cubic centimeters per mole.
There are two methods for estimating VB: (1) from
atomic and structure diffusion volume increments
(see Section 4.4.1) and (2) from the Le Bas volume
(see Section 4.4.2). This program implements both
methods, which are assigned FSG method 1 andFSG
method 2, respectively. In FSG method 2, a mean
value of 0.875 is used for the constant in Equation 31
(seeLyman, etal., 1990, ch 17, p 13). The calculation
screens for FSG methods 1 and 2 are shown in
Figures 21 and 22, respectively.
WL method
This method (Equation 34) is usable for a wider range
of compounds and temperatures than the FSG method
(Wilke&Lee, 1955).
D = •
B'T
2/3
(34)
where B' = a function of molecular weight of air and
that of the chemical of interest,
P0 = atmospheric pressure in atmospheres,
OAB = characteristic length of the chemical of
interest interacting with air, and
Q = collision integral.
Calculations of B', OAB, and Q are by no means
difficult, but rather, are tedious. The user is encourag-
ed to read the original paper for more details (Lyman,
et al., 1990, ch. 17, pp!3-14). The calculation screen
for the WL method is shown in Figure 23.
4.5.2 Diffusivitv in Water
The Hayduk and Laudie method for estimating the
diffusivity in water is based on Equation 35 (Hayduk
and Laudie, 1974):
13.26X10"5
V
0.589
LB
where DL = diffusivity in water in square centi-
meters per second,
22
-------
User's Guide
>r Diffusivity in Air - FSG Method (1)
Chemical Formula & Structure
Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Chlorine (Cl)
Sulfur (S)
Rings *
p
F
F
!°
lo"
* Including aromatic and heterocyclic rings.
Temperature (°C) |23.0
Pressure (atm) h Q
? Help
tjt, Pastel Exit
Figure 21. Calculation Screen for Diffusivity in Air with FSG Method 1,
in Which the Molar Volume Is Estimated from Atomic and
Structure Diffusion Volume Increments.
• r Diffusivity in Air - FSG Method (2) Q@S
_, . _ 1 o CU
Carbon (C) |o
^f
Hydrogen (H) 15 [|J
Oxygen (0), except below lo
0 in methyl esters/ethers lo
0 in ethyl esters/ethers p
0 in higher esters/ethers p
0 in acids 0
0 joined to S, P, S [o
Nitrogen (N), double bound p
Nitrogen (N), primary amines p
Nitrogene (N), 2nd amines 15
I
I
3
I
I
I
I
I
I
Bromine (Br) [jfl ^1
Chlorine (Cl) 15 ^
Fluorine (F) 15 |^
Iodine (1) JO ^]
Sulfur (S) |o *|
3-rnembered ring p |5
4-membered ring 0 ^|
5-membered ring p H
6-membered ring 0 *
Naphthalene |o ^j
Anthracene JO ^J
? Help
Temperature ("C) |25.0
Pressure (atm) 1.0
'^^^^^^^^^^^^^^^^
r^g
J|_ Close
Figure 22. Calculation Screen for Diffusivity in Air with the FSG
Method, in Which the Molar Volume Is Estimated from the
Le Bas Volume.
23
-------
Program PARAMS
Diffusivity in Air - WL Method
Chemical Formula £ Structure
Carbon (C)
Hydrogen (H)
Oxygen (0), except below
0 in methyl esters/ethers
0 in ethyl esterslethers
0 in higher esters/ethers
0 in acids
0 joined to S, P, S
Nitrogen (N), double bounded
Nitrogen (N), primary amines
Nitrogen (N), 2nd amines
O
0 *
0 t
0 v
o C
F3
F^
Bromine (Br)
Chlorine (Cl)
Fluorine (F)
Iodine (1)
Sulfur (S)
3-membered ring
4-membered ring
5-mernbered ring
6-mernbered ring
Naphthalene
Anthracene
o If
n
Temperature (°C) o
Boiling Point (°C) J80.1
Pressure (atm) H.O
7 Help
Paste S: Exit
Ii
[Sa, .-.
epjCopy |
Figure 23. Calculation Screen for Molecular Diffusivity in Air with the WL
Method.
rjw = viscosity of water (centiPoise), and
V^ = Le Bas volume in cubic centimeters per
mole.
The user needs to enter the molecular formula in the
calculation screen (Figure 24), and the two parame-
ters in Equation 35 (r/w and VL^) are calculated
internally based on methods described in Sections
4.8.2 and 4.4.3, respectively.
4.5.3 Diffusivity in Solids as a Function of
Molecular Weight
For a given solid material and a class of chemicals,
correlation exists between the diffusivity of a chemi-
cal and its molecular weight (Bodalal, et al., 2001;
Cox, et al., 2001). The two constants in Equation 36,
A and w, are found from experimental data. Data for
nine material/chemical class combinations are avail-
able in this program.
D =
A
m"
(36)
where Ds = diffusivity in solid in square meters per
second,
A = a coefficient specific to a material and a
compound class,
m = molecular weight in grams per mole, and
n = an index specific to material and a com-
pound class.
Values of A and n for different materials are provided
in the calculation screen (Figure 25). When the user
clicks on a material in the table, the selected mate-
rial/chemicals will be displayed at the upper-right
corner. In Figure 25, gypsum board/aromatics are
selected and, thus, A = 44.81 and n = 5.99.
4.5.4 Diffusivity in Solids as a Function of
Molar Volume
Correlations described in Section 4.5.3 are specific to
24
-------
User's Guide
Diffusivity in Water - Hayduk ft Laudie Method
Chemical Formula & Structure
Carbon (C)
Hydrogen (H)
Oxygen (0), except below
0 in methyl esters/ethers
0 in ethyl esters/ethers
0 in higher esters/ethers
0 in acids
0 joined to S, P, S
Nitrogen (N), double bound E j^j
Nitrogen (N), primary amines D j^j
Nitrogene (N), 2nd amines JO H
F^
r^
F^
F^
m
F^
Bromine (Br)
Chlorine (Cl)
Fluorine (F)
Iodine (I)
Sulfur (S)
3-rnembered ring
4-rnemberedring
5-rnembered ring
6-rnemberedring
Naphthalene
Anthracene
F^
F^
F^
Temperature (°C)
7 Help
Paste 8, Exit
Figure 24. Calculation Screen for Molecular Diffusivity in Water.
•T Diffusivity in Solids for Individual Chemical Classes
Correlation
Ds =A/H?
Ds = diffusivity in solid (m2/s),
m = molecular weight (g/mol), and
A and n are constants.
Material
Chemicals
nl
Pf
A
Aiomatics
Oriented strand board Alkanes
Particle board
Particle board
4.481 E1
5.99
0.9816
Your selection
Gypsum board / Aromatics
Enter molecular weight (g/mol)
es
atics
ydes
1.450E7
1.692E7
8.355 0.9866
3.5
3.396E8 9.33
0.9618
0.8328
Click on a rnatenal to select
1& Copy
Figure 25. Calculation Screen for Diffusivity in Solid Material. This
Method Is Specific to Given Material/Chemical Class
Combinations.
25
-------
Program PARAMS
certain material/chemical class combinations. To
loosen such restrictions, Guo (2002b) suggested that
Ds be correlated to the molar volume. Equation 37
can be applied to mixed chemical classes.
\n(Ds)=A+B\n(VJ
(37)
where Vm = molar volume in cubic centimeters per
mole.
Coefficients A and B for different materials are
provided in the calculation screen (Figure 26). The
user is expected to select a material, enter the molar
volume and then click the button. A
calculator is available for computing the molar
volume.
4.6 Solid-Air Partition Coefficient
Solid-air partition coefficient is a key parameter in
models for pollutant emissions from building materi-
als and is defined by Equation 38.
KP=^ (38)
where KP = solid-air partition coefficient (dimen-
sionless),
Cs = concentration in solid material in
mass/volume, and
Ca = concentration in air at equilibrium with
solid phase in mass/volume.
Thus, if a chemical has a large K, it tends to stay in
the solid phase. The reciprocal of K is known as the
air/solid partition coefficient.
4.6.1 Material and Chemical Specific Methods
For a given solid material and a chemical class,
correlations exist between solid-air partition coeffi-
cient and vapor pressure (Equation 39 ).
(39)
where P = vapor pressure in millimeters Hg).
Constants B and n have been reported for ten mate-
rial/chemical class combinations (Zhao, et al, 1999;
Bodalal, et al, 2001). All are implemented in this
program, and the data are shown in the calculation
Diff usivity in Solids for Mixed Chemical Classes
Correlation
Ds=A-Bln(v)
where D$ = difiusivity in solid (m2/s),
v = molar volume (g/mol), and
A and B are constants.
Material
Pf
-1.536
Oriented strand board 19.73
-4.674
•8.401
0.997
0.973
Particle board
Plywood
Vinyl tile
10.59
-0.6787
-3.546
•6.970
-4.720
-4.286
0.785
0.815
0.917
Click on a material to select
Your selection
Gypsum hoard
Enter molar volume (cnWmol)
Figure 26. Calculation Screen for Molecular Diffusivity in Solid Materials.
This Method Is Not Specific to a Particular Compound Class.
26
-------
User's Guide
screen (Figure 27). The square of correlation coeffi-
cient (r2) ranged from 0.689 to 0.997.
4.6.2 Method for All Materials and Compound
Classes
By combining all experimental data (see Section
4.6.1), Guo (2002b) found a correlation for all materi-
als and compound classes. Equation 40 («=56; r2=
0.734) is useful for roughly estimating the solid-air
partition coefficient without any experimental data.
Figure 28 shows the calculation screen.
\D(KP) = 8.86- 0.785 ln(P)
(40)
4.7 Volatility of Organic Compounds
The software has algorithms for computing the vapor
pressure of individual organic compounds and the
total vapor pressure of petroleum-based solvents.
•r Solid/Air Partition Coefficient for Individual Chemical Classes
Correlation
K = B/PH
where K= solid/air partition coefficient (-),
P = vapor pressure (mm Hg), and
B and n are constants.
Material
Chemical class B
aromatics
Oriented strand board alkanes
1.069E+04
Particle board
Particle board
<
aromatics
aldehydes
1.073E+04
1.305E+04
1.037E+04
Click on a material to select
bypsum board • aromatics
Enter vapor pressure (mm Hg)
Figure 27. Calculation Screen for Solid-Air Partition Coefficient. This
Method Is Material and Chemical Specific.
•r Solid/Air Partition Coeff. for All Chemicals/Materials
- H X
Enter vapor pressure (mm Hg):
Figure 28. Calculation Screen for Solid-air Partition Coefficient. This
Method Is Not Specific to Compound Classes.
27
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Program PARAMS
4.7.1 Makar Method for Pure Organic Com-
pounds
A method developed by Makar (2000) allows the user
to estimate the vapor pressure for an organic com-
pound by knowing (1) its compound class, (2) the
carbon number in the molecule, and (3) the temp-
erature of interest. In doing so, Makar divided or-
ganic compounds into 39 classes (e.g., n-alcohols, n-
alkanes, and polyaromatics). For each compound
class, the 12 coefficients in Equation 41 were found
based on available experimental data and are given in
a table.
Iog10 P = a0
al T+ a2 T2
a
(41)
where P is in millimeters Hg and Tis in Kelvins.
In general, the correlations are good. This method is
very useful in the absence of experimental data at
room temperature. It is the user's responsibility, how-
ever, to determine the class to which a given com-
pound belongs. In other words, the user must know
the molecular structure of the compound.
Coefficients for different compound classes are
stored in a database table, invisible to the user. The
user is expected to select a compound class from the
list, select the carbon number, and enter the tempera-
ture (Figure 29). Note that the range of allowable
carbon numbers for each compound class is defined
by the method developer.
-I* Vapor Pressure by Compound Class
I Select .1 Compound Class
Acetate;
n-Alcohols
Aldehydes
n-Alkyl-Cyclopentanes
n-Alkyl-Cyclohexanes
Dimethyl-Cycloalkanes
Unsubstituted Cycloalkanes
Multiple-lso-Bran:hed Alkanes
Single-lso-Bran:hed Alkanes
n-Alkanes
Single-Tert-Branched Alkanes
Tert-and-lso-Di-Branched Alkanes
Di-Tert- Alkanes
2-Alkyl-1-Alkenes
3+Alkyl-1-Alkenes
Internal Alkenes
n-1-Alkenes
1-Alkynes
n-An hydrides
n-Amines
Bromoalkanes
You selected:
Acetates
Carbon number
Temperature (°C) 25
Figure 29. Calculation Screen for Estimating the Vapor Pressure Based
on Compound Class.
28
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User's Guide
4.7.2 Total Vapor Pressure of Petroleum-
Based Solvents
Predicting the emissions of TVOCs from petroleum-
based paint or solvents requires knowledge of the
total vapor pressure for TVOC. Assuming ideal
solution, the total vapor pressure is the sum of the
partial pressures for all compounds in the solvent
mixture, but it is difficult to quantify all the compo-
nents of a petroleum-based solvent, which contains
hundreds of compounds. Guo, et al. (1999) suggested
that total vapor pressure be approximated by that of
an imaginary solvent consisting of the known major
components in the mixture (Equation 42). Knowledge
of the contents of about a dozen major components in
the solvent—normally achieved by GC analysis—is
sufficient for a reasonable estimate of the total vapor
pressure.
(42)
To simplify the calculations, this program contains a
mini-database for the properties of common VOCs in
petroleum solvents (Figure 30). The user is expected
to enter the contents of individual VOCs in the
coating materials in the last column. The user can, of
course, add new VOCs to the table. This method also
calculates the average molecular weight based on
Equation 43.
m =
(43)
4.8 Properties of Water
The software has algorithms for calculating the vapor
pressure and viscosity of water.
4.8.1 Vapor Pressure of Water
The vapor pressure for water is calculated from
Equation 44 (Yaws, 1994a, page 345)
•!' Total vapor pressure for petroleum solvent
Enter VOC contents here:
Compound
Formula
MW
octane
nonane
decane
undecane
dodecane
toluene
ethyl benzene
0-nylene
rn-xylene
p-xylene
o-ethjil toluene
C8H18
C8H20
C10H22
C11 H24
C12H26
rn-phhnl hnli ipn
C7H8
C8H10
C8H10
C8H10
C8H10
C9H12
114
128
142
156
170
92
106
106
106
106
120
7 Help
VP (mm Hg) Content (rng/g)
12.324
20
4.144
1.575
0.616
0.253
24.473
8.850
5.887
7.240
7.710
2.526
50
125
60
10
; Paste & Exit
A
Figure 30. Calculation Screen for Total Vapor Pressure of Petroleum-Based
Solvents.
29
-------
Program PARAMS
+ DT+ET2
(44)
where Pw0 = water vapor pressure in millimeters Hg,
T= temperature in Kelvins,
,4 = 29.8605,
J8 = -3.1522xl03,
C =-7.3037,
£> = 2.4247xlQ-9, and
E= 1.8090X1Q-6.
Temperature is the only user input (Figure 31).
4.8.2 Viscosity of Liquid Water
The absolute viscosity of liquid water is calculated
from Equation 45 (Yaws, 1994b).
log10/7= A+B/T+CT+DT2
(45)
where 77 = liquid viscosity (centiPoise),
T= temperature in Kelvins and 273 K < T <
642 K,
,4 = -10.2158,
B= 1.7925X10'3,
C=1.7730xlO-2, and
£> = -1.2631xlO-5.
Temperature is the only user input in the calculation
screen (Figure 32). Note that 1 centiPoise = 0.01
Poise = 0.01 (g/s/cm).
Vapor Pressure for Water
- n x
Enter indoor temperature (°C):
i
Figure 31. Calculation Screen for Water Vapor Pressure.
Viscosity for Water
Enter indoor temperature (°C):
Figure 32. Calculation Screen for Water Viscosity.
30
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User's Guide
References
ASTM (1977) Standard methods for evaporation
rates of volatile liquids. In: Annual Book of ASTM
Standards, Part 27, American Society of Testing and
Materials, Philadelphia, PA, pp. 716-726.
Bennet, C.O. and Myers, I.E. (1982) Momentum,
Heat, and Mass Transfer, 3rd ed., McGraw-Hill, New
York, NY, p 504.
Bodalal, A., Zhang, J.S., Plett, E.G., and Shaw, C.Y.
(2001) Correlations between the internal diffusion
and equilibrium partition coefficients of volatile
organic compounds (VOCs) in building materials and
the VOC properties, ASHRAE Transactions, Vol.
107, pp 789-800.
Chinn,K.S.K. (1981)^4SimpleMethodforPredicting
Chemical Agent Evaporation. U.S. Army Dugway
Proving Ground, Dugway, UT, DPG-TR-401, p 4.
Cox, S.S., Zhao, D., and Little, J.C. (2001) Measur-
ing partition and diffusion coefficients for volatile
organic compounds in vinyl flooring, Atmospheric
Environment, Vol. 35, pp 3823-3830.
Evans, W.C. (1994) Development of continuous-
application source terms and analytical solution for
one- and two-compartment systems. In: Tichenor, B.
A. (Ed), Characterizing Sources of Indoor Air Pollu-
tion and Related Sink Effects, ASTM STP 1287,
American Society of Testing and Materials, Philadel-
phia, PA, pp. 279-293
Fuller, E.N., Schettler, P.O., and Giddings, J.C.
(1966) A new method for prediction of binary gas-
phase diffusion coefficients, Industrial and Engineer-
ing Chemistry, Vol. 58, pp!9-27.
Guo, Z., Chang, J.C.S., Sparks, L.E., andFortmann,
R.C. (1999) Estimation of the rate of VOC emissions
from solvent-based indoor coating materials based on
product formul ati on, A tmospheric Environment, Vol.
33, pp 1205-1215.
Guo, Z. (2002a) Review of indoor emission source
models-part 1. overview, Environmental Pollution,
Vol. 120, pp 533-549.
Guo, Z. (2002b) Review of indoor emission source
models - part 2. parameter estimation, Environmental
Pollution, Vol. 120, pp 551-564.
Guo, Z. and Roache, N. F. (2003) Overall mass
transfer coefficient for pollutant emissions from small
water pools under simulated indoor environmental
conditions, The Annals of Occupational Hygiene,
Vol. 47, pp 279-286.
Hayduk, W. and Laudie, H. (1974) Prediction of
diffusion coefficient for non-electrolysis in dilute
aqueous solution, American Institute of Chemical
Engineers Journal, Vol .2,611-615.Cited by Lyman,
etal. (1990).
Koontz, M. (2001) Wall Paint Exposure Model
(WPEM) Version 3.2 User's Guide, developed by
Geomet Technologies, Inc., Germantown, MD, for
U.S. EPA Office of Pollution Prevention and Toxics,
Washington, DC, and National Paint and Coatings
Association, Washington, DC.
http://www.epa.gov/opptintr/exposure/docs/wpem.
htm (accessed on June, 2005).
31
-------
Program PARAMS
Lyman, W.L., Reehl, W.F., and Rosenblatt, D.H.
(1990) Handbook of Chemical Property Estimation
Methods: Environmental Behavior of Organic
Compounds, American Chemical Society, Washing-
ton, DC.
Mackay, D. and Matsugu, R. (1973) Evaporation
rates of liquid hydrocarbon spills on land and water,
The Canadian Journal of Chemical Engineering., Vol.
5l,pp 434-439.
Makar, P. A. (2000) The estimation of organic gas
vapor pressure, Atmospheric Environment, Vol. 35,
pp 961-974.
Reid, R.C., Prausnitz, J.M., and Sherwood, T.K.
(1977) The Properties of Gases and Liquids, 3rd ed.,
McGraw-Hill, New York, NY, pp 58-59.
Southworth, G.R. (1979) The role of volatilization in
removing polyaromatic hydrocarbons from aquatic
environments, Bulletin of Environmental Contamina-
tion & Toxicology, Vol. 21, pp 507-514. Cited by
Lyman, etal. (1990).
Sparks, L., Tichenor, B., Chang, J., and Guo, Z.
(1996) Gas-phase mass transfer model for predicting
volatile organic compound (VOC) emission rates
from indoor pollutant sources, Indoor Air Vol. 6, pp
31-40.
Weast, R.C. (Ed.) (1973)Handbookof'Chemistry and
Physics, 53th Ed., The Chemical Rubber Co., Cleve-
land, OH.
White, P.M. (1991) Heat and Mass Transfer,
Addison-Wesley, New York, NY.
Wilke, C.R. and Lee, C.Y. (1955) Estimation of
diffusion coefficients for gases and vapors, Industrial
Engineering Chemistry, Vol. 47, pp 1253-1257.
Cited by Lyman, et al. (1990).
Wilkes, C., Koontz, M., Rayn, M., and Cinalli, C.
(1996) Estimation of emission profiles from interior
latex paints. In: Indoor Air '96, Proceedings of the 7th
International Conference of Indoor Air Quality and
Climate, SEEC Ishibashi, Inc., Japan, Vol. 2, pp. 55-
60.
Yaws, C.L. (1994a) Handbook of Vapor Pressure,
Vol 4. Inorganic Compounds and Elements, Gulf
Publishing Company, Houston, TX, p-354
Yaws, C.L. (1994b) Handbook of Viscosity, Gulf
Publishing Company, Houston, TX, Vol. 4, p 350.
Zhao, D.Y., Cox, S.S., and Little, J.C. (1999)
Source/sink characterization of diffusion-controlled
building materials. In: Indoor Air 99: Proceedings of
the 8th International Conference on Indoor Air
Quality and Climate, Construct on Research Commu-
nications Ltd., London, UK, Vol. 1, pp. 408-413.
32
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/R-05/066
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Program PARAMS User's Guide, Program Version: 1.0,
Document Version: 1.0
5. REPORT DATE
March 2005
6. PERFORMING ORGANIZATION CODE
7. AUTHORS
8. PERFORMING ORGANIZATION REPORT NO.
Z. Quo (U.S. EPA)
9. PERFORMING ORGANIZATION NAME AND ADDRESS
See Block 12
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
In-house
12. SPONSORING AGENCY NAME AND ADDRESS
U. S. EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
User's Guide, 2003-2004
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES
The EPA Principle Investigator is Zhishi Quo, Mail Code E305-03, Phone (919) 541-0185, e-mail
guo.zhishi@epa.gov
16. ABSTRACT
The report describes a Microsoft Windows-based computer program that implements 30 methods for
estimating the parameters in indoor emissions source models, which are an essential component of indoor
air quality (IAQ) and exposure models. These methods fall into eight categories: (1) the properties of indoor
air, (2) the first-order decay rate constants for solvent emissions from indoor coating materials, (3) gas-
phase, liquid-phase, and overall mass transfer coefficients, (4) molar volume, (5) molecular diffusivity in air,
liquid, and solid materials, (6) solid-air partition coefficient, (7) vapor pressure and volatility for pure organic
compounds and petroleum-based solvents, and (8) the properties of water. Potential users include those
who develop or use IAQ and exposure models and those who develop or use quantitative structure-activity
relationship (QSAR) models. In addition, many calculations are useful to researchers in areas other than
indoor air quality. Users can benefit from this program in two ways: first, it serves as a handy tool by putting
commonly used parameter estimation methods in one place; second, it saves users time by taking over
tedious calculations. It should be pointed out, however, that the methods implemented in this program cover
only a fraction of the parameters that appear in the more than 50 indoor emission source models.
Furthermore, the methods in the current version are mostly for gaseous pollutants; those for particulate
matter are not included.
17.
KEYWORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Atmosphere
Contamination Control
Mathematical Models
Computation
Paints
Mass Transfer
Diffusion
Volatility
Water
Pollution Control
Stationary Sources
13B 14G
20M
06K 07B
12A
11C, 13C
18. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
40
Release to Public
20. SECURITY CLASS (This Page)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77 ) PREVIOUS EDITION IS OBSOLETE
forms/admin/techrpt.frm 7/8/99 pad
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