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Model Report


Last Revision Date: 03/31/2011 View as PDF
General Information Back to Top
Model Abbreviated Name:

Model Extended Name:

Model Overview/Abstract:
A Microsoft Windows-based indoor air quality (IAQ) simulation software package is presented. Named Simulation Tool Kit for Indoor Air Quality and Inhalation Exposure, or IAQX for short, this package complements and supplements existing IAQ simulation programs and is designed mainly for advanced users. IAQX version 1.0 consists of five stand-alone simulation programs. A general-purpose simulation program performs multi-zone, multi-pollutant simulations and allows gas-phase chemical reactions. The other four programs implement fundamentally based models, which are often excluded in the existing IAQ simulation programs. In addition to performing conventional IAQ simulations, which compute the time-concentration profile and inhalation exposure, IAQX can estimate the adequate ventilation rate when certain air quality criteria are provided by the user, a unique feature useful for product stewardship and risk management. IAQX will be developed in a cumulative manner and more special-purpose simulation programs will be added to the package in the future.
Keywords: Indoor air, inhalation exposure, source, sink
Model Technical Contact Information:
Zhishi Guo
Office of Research & Development
National Risk Management Research Laboratory
Air Pollution Prevention & Control Division
Indoor Environment Management Branch

The model was developed and is maintained by Zhishi Guo.

Model Homepage: http://www.epa.gov/nrmrl/appcd/mmd/iaq.html

User Information Back to Top
Technical Requirements
Computer Hardware
Intel Pentium 90 or higher
Compatible Operating Systems
Microsoft Windows 95, 98, NT 4.0, 2000, ME, XP
Other Software Required to Run the Model
Object Pascal
Download Information

The model is publicly available from the U.S. EPA, Office of Research and Development (ORD), National Risk Management Research Laboratory (NRMRL), Air Pollution Prevention & Control Division (APPCD), Indoor Environment Management Branch (IEMB). For copies on disk/CD, please contact:

Zhishi Guo at 919-541-0185 or guo.zhishi@epa.gov

or it can be downloaded http://www.epa.gov/nrmrl/appcd/mmd.html
Using the Model
Basic Model Inputs
Room size, air change rate, sources, sinks, air cleaning devices
Basic Model Outputs
Pollutant concentrations in indoor air or inhalation exposure for individuals
User Support
User's Guide Available?
Documentation is available in electronic format from: http://www.epa.gov/nrmrl/appcd/mmd.html

(1) an abstract or abstract equivalent in the introduction,
(2) schematic/diagram showing model structure and interaction of model components,
(3) equations, equation solution methodologies, and related simplifying assumptions,
(4) example input/output files, and
(5) input and output variable documentation including definitions, units, temporal/spatial dimensions, and temporal/spatial resolution options.

User Qualifications
This package is for advanced users who have basic understanding of the building environments and indoor air quality modeling.

Model Science Back to Top
Problem Identification
A major part of inhalation exposure occurs in the indoor environments because most people spend nearly 90% of their time indoors. The IAQX package provides a tool for the user to estimate the impact of sources, sinks, ventilation and air cleaning on indoor air quality and inhalation exposure.
Summary of Model Structure and Methods
IAQX consists of five stand-alone simulation programs: one general-purpose simulation program and four special purpose simulation program. All of them are deterministic models.
Model Evaluation
Guo, Z. (2000), “Development of a Windowed-based indoor air quality simulation package,” Environmental Modeling & Software, Vol. 15, No. 4, pp. 403-410.
(Note: In this paper, the IAQX package is referred to as STKi, which is the early name of IAQX)

Guo, Z. (2002), “Review of indoor emission source models – part 1. Overview,” Environmental Pollution, Vol. 120, pp 533-549.

Guo, Z. (2002), “Review of indoor emission source models – part 2. Parameter estimation,” Environmental Pollution, Vol. 120, pp 551-564.

Key Limitations to Model Scope
IAQX do not have the capability of stochastic modeling and, therefore, cannot predict population exposure.

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