EPA/600/A-98/027 Defining Requirements and Data Outcomes for Environmental Verification Program for Indoor Air Products David Ensor, Deborah Franke, Linda Sheldon Research Triangle Institute PO Box 12194, Research Triangle Park, NC 27709 Leslie Sparks U.S. Environmental Protection Agency Air Pollution Prevention and Control Division MD-54 Research Triangle Park, NC 27711 ABSTRACT The U.S. Environmental Protection Agency (EPA) has entered into a cooperative agreement with the Research Triangle Institute (RTI) to develop and manage an emissions testing and verification program for certain products used indoors. This program is part of the EPA=s Environmental Technology Verification (ETV) Program. Building on existing test methods, RTI is developing a harmonized test protocol with participation from stakeholders for office furniture as the first industry sector program. The protocol will be validated in laboratories at RTI and Air Quality Sciences and then will be submitted for approval by a stakeholder group representing buyers and users of technology, developers and vendors, and technology enablers. Testing results will be provided to clients, but will also be incorporated in a database of industry-specific statistical averages that may be used for modeling pollutant concentrations within a building. As part of the protocol development process, RTI is using an indoor air quality, outcome-oriented framework to guide discussion of possible outputs from the testing. The stakeholder group is discussing parameters for the testing protocol. INTRODUCTION The lack of an organized and ongoing program to produce independent, credible performance data has been identified as a major impediment to the development and use of innovative environmental technology. The goal of the EPA=s Environmental Technology Verification (ETV) Program is to verify the environmental performance characteristic of commercially ready technology through the evaluation of objective and quality assured data, so that potential purchasers and permitters are provided with an independent and credible assessment of what they are buying and permitting. The ETV strategy document (1) provides an overview of the program and the context of the indoor air products ETV program. The ETV strategy document and other information about the overall ETV program can be found at the ETV web site, http://www.epa.gov/etv/. To explore a wide range of approaches, the EPA has established pilot projects with states, federal agencies, and nonprofit organizations acting as independent verification organizations. Under the ETV program, technologies are verified under specific, predetermined criteria or protocols and adequate data quality assurance procedures. The program will not CERTIFY or guarantee a technology as meeting a standard or performance criteria into the future. Rather, the purpose is to VERIFY or provide creditable data that the product or process performs as claimed by the developer or vendor. The Research Triangle Institute (RTI) has one of these pilot programs to verify indoor air products. This paper discusses the organization of the indoor air pilot program and the development of protocols. For indoor air products, commercially ready technology implies that existing test methods are ------- available. Thus our protocol development reviews existing test methods and harmonizes them so that our verification testing can balance the needs of the stakeholders. We use an outcome-oriented framework to provide context to study tradeoffs in the harmonization process. The verification statements are being developed to provide sufficient, useful information to users and modelers. INDOOR AIR PRODUCTS PROGRAM The goal of RTFs Indoor Air Products ETV program is to test products and to validate vendors' claims related to product emissions and contamination removal. Claims for products may include reduced emissions, pollution prevention, and health-related concerns. One driver for the program is the procurement requirement for "green" products by federal and state agencies (2). In addition, potential interest by private consumers in "green" products has prompted the labeling and listing of products by several organizations, including EPA (3). Ultimately, high quality test data will be critical for decisions in selection of products by purchasers or specifiers based on environmental preferences. For this program, the overall ETV goals and operating principles have been tailored to meet the needs of the indoor air quality (IAQ) community. RTI has identified two general types of indoor air product claims suitable for verification: Pollution prevention claims of low emitting products. These include products that, when installed in the indoor space, have low emission rates over the life of the product. Also included are products capable of reducing susceptibility of items to microbial growth, thus helping to improve IAQ. The pollution prevention claims examined in this program are related only to product use and not to manufacturing or disposal of the product. Contaminant removal claims. These include filters, absorbers, and air cleaners that directly remove airborne particles and gases. They may also include surface cleaning products that would improve IAQ through a cleaner environment. The program will initially address chemical emissions and ventilation air filtration. This paper will focus on the verification of emissions from office furniture, one of the first products to be addressed under the program. Because of both the hazardous air pollutant list in the Clean Air Act Amendments of 1990 and the public's concern about chemicals in the home, companies are studying the chemicals used in the manufacturing of their products. Through pollution prevention or control of the chemicals used in manufacturing, the chemical emissions from these products during use may decrease. In the past, it has been difficult for buyers and users of products to determine what chemicals might be emitted from products or to confirm claims made by manufacturers. The ETV indoor air products program will allow companies to have their products tested and to give customers the results of that testing. Emissions tests are generally performed in environmental chambers. Over the last several years considerable work has been reported on emissions chamber testing. An American Society for Testing and Materials (ASTM) guide (4) is available for small chamber testing. Recently, additional suggestions have been made for improvements to the guide (5). Testing of some products, including office furniture and office equipment, is performed in large chambers. RTI and Air Quality Sciences (AQS) currently provide emissions testing for commercial clients using both small and large chambers. RTI is the verification organization for the project with responsibility for overall management and quality assurance (QA). AQS, a leader in chamber emissions testing, is a subcontractor. For each product sector addressed in the program, a separate stakeholder group is being used to provide guidance. The stakeholder group representation includes: , buyers and users, developers and vendors, with trade associations representing smaller companies, and enablers, including consulting engineers, architects, and state agencies. In addition, the program has included the part icipation of selected laboratories experienced with the proposed test method and other technical aspects of the program. Stakeholder input to the protocol development is important for two reasons: the protocol needs to be as comprehensive as possible, and ------- the members with power to specify a product should be motivated to use the protocol to support their product purchase decisions. Stakeholders should have an interest in the testing program to participate, as illustrated by the office furniture program. In the last few years, the State of Washington (6) and the EPA (7) have required emissions testing data for bids to supply office furniture to new office buildings. The State of California adopted guidelines for low emitting materials and furnishings for office buildings (8). The trade organization for the commercial furniture industry, BIFMA International, Grand Rapids, Michigan, was approached about a year ago by the U.S. General Services Administration to discuss an effort to harmonize the emissions testing requirements. A single test protocol with wide acceptance would reduce effort required by purchasing organizations to prepare specifications (buyers and users), reduce duplication of testing (developers and vendors), and improve the quality of information available to the purchasing community (enablers). RTI is holding stakeholder meetings for each industry sector about every 4 months. In addition, the Internet is being used for communication. RTI has established a Web site for the project; http://etv.rti.org. The site contains a description of the program, a calendar of future events, a summary of meetings, and stakeholder communications. Forums have been established for further discussion of the individual industry sector programs. There are also links to participating organizations and related programs. The verification program must be built on a process that will yield quality data. The ETV pilot verification organizations are expected to follow a documented quality management process as specified by a quality system such as in the ANSI/ASQC E4 (9) or ISO 9001 (10) guidelines. EPA guidelines (11) are followed for project level QA. The testing program is conducted at a QA level with sufficient rigor to support strategic decision making. Specific QA project plans (QAPPs) are required for testing each product sector. Test protocols should include sufficient quality control (QC) procedures and data acceptance criteria to ensure that results from proficient laboratories can be accepted. A laboratory proficiency program with interlaboratory comparisons is required for all laboratories involved in the program, and will allow for laboratories to be added to the program. More than one laboratory with the facilities and expertise to conduct the protocol is necessary for the acceptance of an ongoing verification program. Multiple laboratories facilitate competition to assure cost effective testing and capacity to satisfy test demand. PROTOCOL DEVELOPMENT In this verification program, a protocol is the complete technical package to support the product sector testing program. It contains: laboratory test methods, product definition and acquisition methods, supporting QA/QC plans, data reduction procedures, and communication of the results. While other ETV pilot programs may need to have specific test protocols for each technology, the RTI product-based program can use a single protocol for all products within an industry sector. RTI plans to use existing test methods and standards as much as possible. ASTM D5116-90, Standard Guide for Small Scale Environmental Chamber Determination of Organic Emissions from Indoor Materials/Products (4), is a starting point for emissions test method development. The ventilation air filter protocol will use American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Test Standard 52.2P (12), now under development, for the protocol. RTFs ETV program will operate as a customer-driven business with the stakeholders as the customers. As the emissions chamber testing for office furniture is being defined, the stakeholders representing various groups balance their separate needs. The users, organizations that buy large r quantities of office furniture, want to be able to show that they are addressing the indoor air concerns of their workers and satisfying any pollution prevention requirements of their environmental management plans. The office furniture industry wants to ensure that the testing will be accepted by as wide a user base as possible and that the cost, both in money and time, will be reasonable. The enablers want to ensure that the data obtained will be sufficient for modeling and risk assessment. ------- The end uses of the testing data by the stakeholder group dictate the verification process from first step to the end. The information must have a sound scientific basis, be complete, and be quality assured to be useful to the widest range of stakeholders. While not an exhaustive list, possible uses of the data include: assessment and modeling, input for environmental management improvement plans, marketing, purchase decisions, and tradeoff analysis. The group has input from experts in chamber testing, modeling, risk assessment, and IAQ. This paper is not addressing any of those areas specifically, but is looking at the process of developing test methods that balance the needs of stakeholders. The process as described specifically addresses emissions chamber test methods for office furniture, but the process is useful for most emissions chamber testing and could be adapted for other testing as well. Protocols currently in use by RTI and AQS, based on ASTM D5116-90 (4), were the starting points for protocol development. The purchasing specifications from the EPA (7) and the State of Washington (6) were used as starting points for defining parameters. Other screening and testing programs were reviewed, including: Danish Indoor Climate Labeling Program (13). This program focuses on volatile organic compounds (VOCs) emitted from building materials. Because emissions decay rapidly for many materials, the program reports the time required for emissions to decay below a threshold value for the specific VOC. This threshold value is based on either odor detection thresholds or mucus membrane irritation thresholds. The testing program primarily uses the Field and Laboratory Emission Cell (FLKC). European Data Base on Indoor Pollution Sources in Buildings (14). To ensure the quality of the data to be collected, the protocol provides requirements for the sampling, transport, storage, and preparation of the products. This protocol was based on ASTM D5116-90 (4) and others. Levin and Hodgson's proposal for screening building materials (15). They propose to use small chambers and to do short screening tests of 24 hours where possible. They suggested a 96-hour test for office work stations using a large environmental chamber. Canadian Environmental Choice Label Program, administered by TerraChoice Environmental Services, Guideline ECP-66, Office Furniture and Panel Systems (16). The emissions testing is based on and uses the same limit as the State of Washington specification (6). The labeling program is much broader than just emissions testing: it includes many environmental management requirements. Framework Sparks et al. (17) describe the principles of assessing risk from product source testing. The purpose of the ETV program is not to assess risk; however, the ideas are valuable for organizing the ETV technical approach. With appropriate test protocols, the data could be used for many applications, including irritancy and risk. As shown in Figure 1, the process begins with the source or emissions test. A product sample is placed in an environmental test chamber under carefully controlled conditions of temperature, humidity, air exchange rate, and mixing. Purified air flows through the chamber at a known air exchange rate. The chemicals emitted from the product are measured in the chamber air samples using standard methods for sampling and analysis. In a chamber test, gas chromatography (GC) and/or GC/mass spectroscopy (MS) data are collected along with environmental data such as air flow rate, temperature, and relative humidity. These data are used to determine a chamber concentration (mass/volume) for individual chemicals and total organics. From the measured concentration as a function of time, one can calculate an emission rate of the product (mass/time per unit source size). Dunn and Tichenor (18) and Sparks et al. (17) discuss emission rates, which may be constant or modeled as a function of time, lI ------- A constant emission rate (or emission faetor) R can be calculated as R = C(N/L) - (1) where C = steady-state chamber concentration (mass/volume), N = chamber air exchange rate (air changes/time), and L = chamber loading (chamber volume/source size). For time-dependent emission rates, such as the first and second order equations, R = R0e-lt, R = R0e-"'+ Rje'1", (2) the constants may be determined by curve fit to the chamber concentration versus time data. Other expressions of the emission rate can be found in Guo et al. (5), There are many source models used to determine the emissions (17). For the verification program testing, the results will be given as an emission rate or rate equation. This information can then be used in various models by the users and enablers. To predict room air concentrations, the emissions rate (source model) can be combined with building characteristics in an IAQ model. For office furniture, one could define a standard room configuration for the model, and then use emission rates from various products to estimate room air concentration. Room components could include office furniture, carpet, paints, ceiling tiles, wallboard, or other building materials. The air exchange rate and surface air velocity are parameters in the model. The time for decay could support a model where the building is flushed out before occupancy. A user should have the flexibility of determining an overall building configuration, allowing tradeoffs between various components, rather than requiring low emissions from only one product. IAQ model predictions are then used by an exposure model to predict individual exposure. One type of exposure is instantaneous, Ej5 E, = C(t) (3) where C(t) = concentration at time t to which an individual is exposed. There is also cumulative exposure Ec, between times t, and t2 Ec = ]c(t)dt. <4' h Working with the framework, we could identify test parameters that will influence the ultimate usefulness of our results. These parameters are being discussed by our stakeholder group, with input from the participating laboratories. For office furniture, the parameters are: * The product to be tested. Can a standard configuration represent a product line? Is fabric included? What components of a work station are most critical for emissions? * Chemicals to be tested. For office furniture, chemicals were identified in previous testing, in a California guideline (8), and in EPA (7) and State of Washington (6) protocols. It can also be specified that, when other chemicals have relatively high concentrations, they should be recorded. * How the product is to be selected, acquired, shipped, stored, and prepared before testing. * Chamber conditions including type, size, mixing, air flow rates, temperature, and relative humidity. ------- The sampling times and duration of the test. The initial furniture tests for the State of Washington lasted for 6 weeks. Because the emissions decayed rapidly, the length of the test was reduced. Current tests are 5-7 days, with six samples taken. Sampling and analysis techniques. If total VOC is used, there should be a standardized definition of it. Sample collection method(s) should allow for collection of all target chemicals. If modeling is required, the model should be provided and parameters specified. Information to be provided in the verification report. The verification report should be user friendly and provide information in a way to facilitate comparison among products. Verification Statements Each of the ETV pilot programs is developing a model verification statement to report the testing results. The statements will include information on the testing protocol and the test results. They will not have ranking of products. Examples of these can be seen on the EPA's ETV Web site (http://www.epa.gov/etv/). The statements arc signed by the head of the EPA laboratory responsible for the pilot program. There are also verification reports which give more details of the testing. In the ETV indoor air products program, we are reporting emissions rate data which may be input to models. The testing information can be reported or used in other ways. In the Danish building materials program (13), the results are given as a time for the emissions to reach an acceptable concentration. In labeling and certification programs, the results are generally given as a pass or fail, based on a predetermined cutoff level. Other possible output information includes time dependence (including peak emissions), odors, total emissions, and risk. Our decision to report emissions rate as the primary output was made after evaluating a worksheet developed to organize the applicability of the possible reporting methods for use in studying pollution prevention, irritancy, and both long- and short- term health effects. The worksheet also included some of the parameters discussed above. Figure 2 is a copy of the worksheet. We expect our verification statements to provide other user-oriented information, such as providing the results of an IAQ room model using various components of the room. In the case of office furniture, the room could Include a standard work station with chairs, carpet, ceiling tile, wall paint, and office equipment. Detailed information, including the complete data set and regression equations, will be available in either the verification statement or the report. CONCLUSIONS The indoor air products pilot ETV program is being established to provide verification testing of emissions and contaminant removal claims for products. The test protocols are being developed and organized using a outcome-oriented framework. A stakeholder group representing manufacturers and vendors, buyers, users, and enablers is helping to determine testing parameters, based on their collective needs. A verification statement will be issued by EPA giving the testing results of each product. Office furniture is the first industry sector in the program; other sectors include ventilation air filtration and office equipment. RTI expects to be testing products in late 1997 and issuing verification statements by early 1998. This approach is proving to be an effective method of technology transfer for the results of EPA-sponsored research into self-sustaining programs. ------- U.S. EPA, Environmental Technology Verification Program: Verification Strategy, EPA/600/K- 96/003; U.S. EPA, Office of Research and Development: Washington, 1997. U.S. EPA, Guidance on Acquisition of Environmentally Preferable Products and Sennces: Solicitation of Comments, Federal Register Vol. 60. No. 189 50722-50736, September 29, 1995. (See also http://www.epa.gOv/docs/opptintr/p2home/index.html#F.) U.S. EPA, Consumer Labeling Initiative Phase 1 Report, Office of Pollution Prevention and Toxics: Washington, 1997. (See also http://www.epa.gov/opptintr/labeling/phasel/.) ASTM, ASTM D51J6-90, Standard Guide for Small Scale Environmental Chamber Environmental Chamber Determination of Organic Emissions from Indoor Materials/Products, American Society for Testing and Materials: West Conshohocken, PA, 1990. Guo, Z., Tichenor, B.A, Krebs, K.A., and Roache, N. F., "Considerations on Revisions of Emissions Testing Protocols," in Characterizing Sources on Indoor Air Pollution and Related Sink Effects. B.A. Tichenor, Ed.; American Society for Testing and Materials: West Conshohocken, PA, 1996; pp. 225-235. Brown, J., Sadie, L.S., and Black, M.S., Indoor Air Quality Specification for Washington State Natural Resources Building and Labor and Industries Building; State of Washington Department of General Administration: Olympia, 1989. U.S. EPA, U.S. EPA New Headquarters Project. Gruzcn Samton PC, Croxton Collaborative, Associated Architects. Washington, 1995. Alevantis, L.E., Reducing Occupant Exposure to Volatile Organic Compounds (VOCs) from Office Building Construction Materials: Non-Binding Guidelines, Division of Environmental and Occupational Disease Control, California Dept. of Health Services: Sacramento, 1996. ANSI/ASQC, Specifications and Guidelines for Quality Systems for Environmental Data Collection and Environmental Technology Program, E4-1994; American Society for Quality Control: Milwaukee, 1994. ANSI/ASQC, Quality Systemsmodel for quality assurance in designing; development, protection, installing and servicing, Q9001-1994; American Society for Quality Control: Milwaukee, 1994. U.S. EPA, AEERL Quality Assurance Procedures Manual for Contractors and Financial Assistance Recipients. Office of Research and Development: Research Triangle Park, 1994. ASHRAE. Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size. Proposed Standard 52.2P. American Society of Heating, Refrigerating and Air- Conditioning Engineers: Atlanta, 1997. Wolkoff, P. and Nielsen, P. A., "Indoor Climate Labeling of Building Materials: The Experimental Approach for a Prototype." In Characterizing Sources on Indoor Air Pollution and Related Sink Effects. B.A. Tichenor, Ed.; American Society for Testing and Materials: West Conshohocken, PA, 1996; pp. 331-349. Saarela, K., G. Clausen, J. Pejtersen, et al., "European Data Base on Indoor Air Pollution Sources in Buildings, Principles of the Protocol for Testing of Building Materials," in Proceedings of the Indoor Air 96 Conference, Vol. 3:83-88, Tokyo, Japan, July 1996. Levin, H. and Hodgson, A.T., "Screening and Selecting Building Materials and Products Based on their Emissions of Volatile Organic Compounds (VOCs)." In Characterizing Sources on Indoor Air Pollution and Related Sink Effects. B.A. Tichenor, Ed.; American Society for Testing and Materials: West Conshohocken, PA, 1996; pp. 377-391. TerraChoice Environmental Services, Guideline ECP-66, Office Furniture and Panel Systems, Canadian Environmental Choice Label Program, TerraChoice: Ottawa, 1996 Word Perfect file available (See http://www.terrachoice.ca/ecologo.htm.) ------- 17. Sparks, L.E., Moihave, L., and Dueholm, S.. "Source Testing and Data Analysis for Exposure and Risk Assessment of Indoor Pollutant Sources," in Characterizing Sources on Indoor Air Pollution and Related Sink Effects, B.A. Tichenor, Ed.; American Society for Testing and Materials: West Conshohocken, PA, 1996; pp. 367-365. 18. Dunn, J.E. and Tichenor, B.A., "Compensating for Sink Effects in Emissions Test Chambers by Mathematical Modeling," Atmospheric Environment 1988 22, 885-894. ------- Outcome-Oriented Framework for 1AQ Sources Source Source IAQ Exposure Risk Testing Modeling Modeling Modeling Modeling :~ Emissions and Size Ventilation Building factors {e.g., sinks) .... Source usage Occupancy Occupant sensitivity - Dose response Air Concentration Exposure Risk ETV Program for Indoor Air Products Verification Testing Emissions Rates and Models Generalization with IAQ Modeling Building Scenarios Exposure and Risk Modeling Exposure and Risk Scenarios Modeling done by enablers and users~ Figure 1. The outcome-oriented framework for indoor air sources in relationship to the ETV program [after Sparks et al.(17)]. ------- Parameters and Endpoints Long-Term Short-Term Irritancy Pollution Health Effects Health Effects Prevention Parameters Chemicals to be tested Length of test Number of data points Data analysis Output format Emissions data Time to acceptable concentration Pass/fail criteria Figure 2. Worksheet used to evaluate parameters and output format for testing program. ------- KEY WORDS chamber study, filter, emissions, VOC, particles. //' i ¦ ------- NRMRL-RTB-P-244 EPA/60Q/A-98/027 TECHNICAL REPORT DATA IPlease read Inflections on the reverse before compter. 2. 3. ' 4. TITLE AND SUBTITLE Defining Requirements and Data Outcomes for Environ- mental Verification Program for Indoor Air Products S. REPORT DATE 6. PERFORMING ORGANIZATION CODE author(s) d. Ensor, D.Franke, and L. Sheldon (RTlj! and L, Sparks (EPA) 8. PERFORMING ORGANIZATION REPORT NO, 9. PERFORMING ORGANIZATION NAME AND ADDRESS Research Triangle Institute P. O. Box 12194 Research Triangle Park, North Carolina 27709 tO. PROGRAM ELEMENT NO. 11. CONTRACT/GRANT NO, CR 822870-01 12. SPONSORING AGENCY NAME AND ADDRESS EPA, Office of Research and Development Air Pollution Prevention and Control Division Research Triangle Park, NC 27711 13. TYPE OF REPORT AND PERIOD COVERED Published paper; 12/96-6/97 14. SPONSORING AGENCY CODE EPA/600/13 is.supplementary notes APPCD project officer is Leslie E. Sparks, Mail Drop 54, 919/ 541-2458. EPA/AWMA Indoor Air Quality Meeting, RTP, NC, 7/21-22/97. 16. abstract xhe paper discusses a cooperative effort between EPA and RTI to develop and manage an emissions testing and verification program for certain products used indoors. The effort is part of EPA's Environmental Technology Verification (ETV) program. Building on existing test methods, RTI is developing a harmonized test protocol with participation from stakeholders for office furniture as the first industry sector program. The protocol will be validated in laboratories at RTI and Air Quality Sciences and then will be submitted for approval by a stakeholder group representing buyers and users of technology, developers and vendors, and technology enablers. Testing results will be provided to clients, but will also be incorporated in a database of industry-specific statistical averages that may be used for modeling pollutant con- centrations within a building. As part of the protocol development process, RTI is using an indoor air quality, outcome-oriented framework to guide discussion of pos- sible outputs from the testing. The stakeholder group is discussing parameters for the testing protocol. PROTECTED UNDER INTERNATIONAL COPYRIGHT ALL RIGHTS RESERVED, NATIONAL TECHNICAL INFORMATION SERVICE U.S. DEPARTMENT OF COMMERCE 17. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group Pollution Buildings Emission Tests Verifying Office Equipment Mathematical Models Pollution Control Stationary Sources Indoor Air Quality (IAQ) 13 B 13 M 14G 14 B 15E 12A 18. DISTRIBUTION STATEMENT Release to Public 19. SECURITY CLASS (litis Report) Unclassified 21. NO. OF PAGES 20. SECURITY CLASS (This page} Unclassified 22. PRICE EPA Form 2220-1 (9-73) ------- EPA/600/A-98/026 EVALUATING RESIDENTIAL AIR DUCT CLEANING AND IAQ: RESULTS OF A FIELD STUDY CONDUCTED IN NINE SINGLE FAMILY DWELLINGS Russell Kulp1, Roy Fortmann2, Gary Gentry2, Douglas VanOsdell3, Karin Foarde3, Tim Hebert4, Robert Krell4, and Charlie Cochrane4 1 U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA 2 Acurex Environmental Corporation, Research Triangle Park, North Carolina, USA 3 Research Triangle Institute, Research Triangle Park, North Carolina, USA 4 National Air Duct Cleaners Association, Washington, District of Columbia, USA ABSTRACT PB98-140254 A nine-home field study was conducted to investigate the impact of mechanical air duct cleaning (ADC) methods on indoor air quality (IAQ) and system performance. ADC services were provided by the National Air Duct Cleaners Association (NADCA). Only mechanical ADC methods were evaluated. Surface treatments, such as biocides or encapsulants, were not part of the study. Pre- and post-ADC measurements were used to evaluate impacts. These included deposited duct dust measurements, airborne particle and fiber concentrations, microbial bioaerosol and surface sampling, and system performance factors such as temperature, relative humidity, air flow rates, and static pressure. Surface sampling in ducts indicated that mechanical ADC is effective in removing adhered dust and dirt. The particle measurement data could not offer a clear indication that indoor levels can be reduced using mechanical ADC because there was an apparent strong influence from outdoor particle mass concentrations. Mechanical ADC did not significantly reduce bioaerosol or microbial density in the houses studied. Measurements of system performance factors suggest that ADC may have a positive effect. Supply air rates increased between 4 and 32% in eight of the houses and return air flow rates increased 14 and 38% in two of the houses. INTRODUCTION The U.S. Environmental Protection Agency (EPA), Office of Research and Development (ORD) and NADCA are actively engaged in research that is designed to focus on issues related to IAQ, source management, and their relationship to the ADC industry (1). This paper presents the results of a field study performed by the EPA and NADCA Nine residences were studied with the intention of improving our understanding of residential ADC procedures. The objectives were to evaluate mechanical ADC methods commonly used to clean non-porous surfaces and to measure pre- and post-ADC environmental system parameters to investigate any impacts on IAQ and system performance. Surface treatments such as biocides and encapsulants were not a part of the field study. METHODS The study was conducted in nine residential dwellings. Eight of the residences were occupied. The ninth was the EPA's IAQ Test House (TH) in Gary, NC. Each house was equipped with a reproduced by- ma PROTECTED UNDER INTERNATIONAL COPYRIGHT U.S. Department of Commsrcc^^^ | ALL RIGHTS RESERVED. Nalional Technical Information Sumim 1 ..... Springfield,vir,. Z2K1 NATIONAL TECHNICAL INFORMATION SERVICE U.S. DEPARTMENT OF COMMERCE ------- central heating and air-conditioning (HAC) forced air distribution system. ADC had not been performed on the AHU (air handling unit) or duct system for at least 10 years, and all occupants were nonsmokers. Table 1 shows the house characteristics. These houses presented NADCA with a variety of system configurations for ADC. A week-long study was carried out at each house. The Acurex Environmental Corporation and the Research Triangle Institute performed all environmental and system measurements. Table 1. Characteristics of field study test houses No. House Age (yrs) Duct Age (yrs) AHU Age (yrs) Duct Material House Size (m2) No. of Floors 1 20 20 20 a 121.2 1 2 22 22 22 b 141.2 1 3 18 18 0.5 c 134.7 1 4 10 10 10 d 183.9 2 5 9 9 9 d 185.8 2 6 28 not avail. not avail. b 181.6 1.5 7 25 25 not avail. c 92.9 1.5 8 26 26 26 b 185.8 2 9 35 35 not avail. b 139,3 2 a. Galvanized sheet-metal trunk ducts with internal fiberglass ductliner insulation and insulated flexible plastic branch ducts b. Galvanized sheet-metal ducts with external fiberglass wrap insulation c. Galvanized sheet-metal trunk ducts with external fiberglass wrap insulation and insulated flexible plastic branch ducts d. Insulated flexible ducts Sampling procedures and instrumentation were identical for each of the test houses. Pre- and post-ADC measurements included supply and return air duct dust surface mass, airborne particle mass (PM) and fiber measurements, microbiological measurements, temperature, relative humidity, and carbon dioxide (C02), and system performance factors such as static pressure, air flow rates, motor current, and refrigerant temperature. Levels of dust in the ducts (grams per square meter) were determined by collection of deposited dust samples at selected locations using two methods, the Medium Volume Deposition Sampler (MVDS) (2) and the NADCA Standard Method 1992-01 (3). The MVDS was developed for this study so that both pre- and post-cleaning deposition dust levels could be evaluated. The current NADCA Standard Method 1992-01 can be used to evaluate only post-cleaning levels. PM ranges of 2.5 //m (PM25) and 10 ptm (PM10) were measured at three locations, outdoors and at two indoor locations. Measurements were taken using the size selective impactors developed for use in the EPA's Building Assessment Survey Evaluation (BASE) Program (4). 2 ------- Additional particle sampling (particles per cubic meter) was performed using a Climet model Cl-4100. The monitor was used in the >0.5 /xm particle size mode so that ail particles greater than that size were counted. These real-time measurements of particle number concentrations were augmented by use of a LAS-X particle size/counter. The LAS-X was collocated with the Climet and was used to measure room concentrations in the size fraction of approximately 0.1 to 3 um geometric diameters. Fiber concentrations were monitored continuously using a MIE FAM-1 Fibrous Aerosol Monitor. Also, integrated samples of airborne fibers were collected using the NTOSII Method 7400, Asbestos and Other Fibers by PCM (5). Total fiber concentrations were determined in accordance with NIOSH Method 7400B counting rules. Additionally, a filter sample collected prior to ADC and one collected after ADC were analyzed by scanning electron microscope (SEM) to determine the relative abundance of different types of fibers, such as fiber glass, cellulose fibers, and hair. Bioacrosol samples were taken in the ducts and in the houses using either a Mattson-Garvin slit-to-agar sampler or a 1-stage Andersen cascade sampler. Microbial surface density measurements were conducted near where the duct dust deposition samples were taken using filter cassette and sterile swab techniques. Temperature, relative humidity, and C02 concentrations were monitored continuously in the primary living area of each house using the IAQ data logging system developed by the EPA. The mechanical ADC methods and equipment employed by NADCA varied according to the house air distribution system, configuration, and accessibility. ADC methods included portable negative air systems to collect and remove loosened dust and debris. Silica-carbide rotating brushes, air washing with compressed air and air whips, contact vacuuming, and hand-wiping were used to loosen the dust and debris. A substantial effort was expended in cleaning the AHU. It was substantially disassembled and cleaned using hand-wiping and contact vacuuming. The fan, impeller, and scroll housing were removed and wet-cleaned using a non-toxic cleaning fluid. The condensate drain pan, piping, and pumps were inspected and cleaned as necessary. System filters were removed and cleaned or replaced. System cooling coils were wet-cleaned in place using a non-toxic cleaner. Heating coils were wiped and hand vacuumed. NADCA routinely performed a high level of visual inspections during the cleaning to ensure that the ADC process was proceeding satisfactorily. Access to the ductwork was generally through end caps and flexible duct connections. Access doors were installed in the ductwork when access to work areas was difficult. Registers and diffusers were removed and wet- cleaned using a non-toxic cleaning fluid. RESULTS The mechanical ADC methods employed appeared to be effective in removing deposited dust from duct surfaces. Figure 1 shows pre- and post-cleaning measurements in the supply ducts at 3 ------- all of the test houses using the MVDS. Pre-cleaning supply duct deposition ranged from 1.48 g/m2 at house no. 5 to 26.03 g/m2 at house no. 9. Figure 1 shows that post-cleaning supply duct measurements ranged from 0.18 g/m2 at house no. 7 to 0.79 g/m2 at house no. 9. These measurements do not meet the NADCA criterion that residual dust must be less than 0.1 g/m2 (3). 30 25 20 g 15 £ "en | 10 Q TH 4 5 6 House number 1 i i § % s Wi m n ¦L "J Pre-clean ¦ Post-clean Figure 1. Supply duct deposition measurements using MVDS On the other hand, post-cleaning supply duct measurements using the NADCA Standard Method, which are not shown, ranged from 0.003 g/m2 at house no. 8 to 0.036 g/m2 at house no. 2. These measurements meet the NADCA criterion for residual dust (3). Baseline indoor respirable (PM2 5) and inhalable (PM,0) particle mass concentrations were low at the houses, ranging from 4.2 to 32.7 //g/m3, consistent with studies in houses without tobacco smoking (6). Interpretation of the PM measurement data is difficult because outdoor concentrations will have an impact on indoor concentrations. The outdoor concentrations varied over the course of each week-long study making it difficult to determine if the changes in indoor concentrations after ADC were the result of cleaning or due to changes in either outdoor concentrations or occupant activities. For the same reasons, the Climet data were inconclusive with respect to determining ADC impact. Again, these data suggest that the outdoor PM concentrations may have such a strong influence on indoor levels that airborne particle differentials from pre- to post-ADC cannot be detected, A comparison of average pre- and post-ADC bioaerosol levels shows a reduction in airborne fungi; however, these reductions are not considered substantial. None of the test houses were considered to be biocontaminated; therefore, a small change would not be surprising. Pre-ADC airborne fungi levels in the supply ducts ranged from 14 to 646 cfu/rn3 while the post-ADC 4 ------- levels ranged from 2 to 300 cfu/m3. < Bacteria in samples collected from the surfaces of the HAG system were highly variable Pre- ADC bacteria levels ranged from 5 to 1100 cfu/cm2 in the supply ducts and from 5 to 2300 cfii/cm2 in the return ducts, with a mean for all samples of less than 200 cfu/cm2 Mean concentrations of return air bacteria levels were lower after ADC in six of seven houses; however, in the supply ducts, this was true for only four of the occupied houses. Pre- versus post-ADC differences were generally small. Fungal levels were generally higher than bacteria levels, and ADC had the most impact on the ducts with the highest levels of fungi and noticeably reduced the level of fungi in surface samples collected from ducts in most houses. Measurements of system performance factors suggest that ADC had a positive impact. Because of the small sample size and the limited duration of the measurements, it is not possible to quantitatively determine the significance of ADC on system performance and energy use. Generally it resulted in increased air flow to the house. Supply air flows increased between 4 and 32% at eight houses based on measurements at the floor registers and diffusers in the house. Part of the increase in supply air flow rates may have been attributable to minor duct repair. Return air flows measured at the return air grilles increased 14 to 38% at two houses, but were not substantially different after ADC at the other seven houses. AHU blower motor current increased after ADC at the four field study houses where the measurements were performed. Static pressure increased in the return air duct at the six houses with complete measurements. The increases in both blower motor current and static pressure in the return air ducts suggest improved system performance. There was no clear trend for changes in static pressure in the supply ducts or the differential pressures across the cooling coil. Refrigerant line surface temperatures did not provide useful information. DISCUSSION Heating, ventilating, and air-conditioning (HVAC) systems contaminated with adhered dirt and dust deposition are potential IAQ emission sources (7). Research shows that HVAC total volatile organic compound emission rates and odors may be effectively reduced by removing deposition (8)(9)(10). This field study demonstrated that mechanical ADC methods can be an effective source management tool when applied to non-porous bare sheet-metal ducts. Porous surfaces, such as fibrous glass duct lining (FGDL), were not evaluated because houses with FGDJL systems, but without visible surface microbial contamination, could not be found. When FGDL becomes microbially contaminated, the EPA and NIOSH recommend removal and replacement rather than any form of ADC (11). Further research is required to evaluate ADC effectiveness on porous surfaces. Differentials in indoor PM levels from pre- to post-ADC could not be detected. This is consistent with previous research (12) and is probably due to the strong influence of outdoor PM sources (6). Mechanical ADC methods alone did not substantially reduce bioaerosol and culturable surface 5 ------- microbial levels. Surface treatments such as biocides or encapsulants may be required if it is determined that substantial reductions are necessary. To folly evaluate this, future research should include comparisons using mechanical ADC in combination with surface treatments. The MVDS sampling method appeared to be an effective way to quantitatively assess both pre- and post-cleaning duct deposition levels. The MVDS was specially designed for this study and has a higher collection efficiency than the NADCA Standard Method due to the higher air flow rate and use of a brush on the nozzle (3). The data from this study demonstrate that the NADCA Standard 1992-01 criterion of 0.1 g/m2 to document the effectiveness of cleaning should be applied only to samples collected with the Standard 1992-01 method. The criterion of 0.1 g/m2 is not appropriate for samples collected with the MVDS sampling method. Results from other EPA research (13) suggest that a criterion of approximately 0.5 g/m2 may be more appropriate for samples collected with the MVDS. Results of measurements of IIAC system-related parameters suggest that there is a positive impact on HAC system performance from mechanical ADC. These measured impacts cannot be considered significant due to the small study population and the short monitoring period. To substantiate these findings, further research is required. REFERENCES 1. Kulp, R.N. EPA begins air duct cleaning research, Inside IAQ, EPA's Indoor Air Quality Research Update. EPA/600/N-95/004, Spring/Summer 1995, pp. 10-11. Environmental Protection Agency, Research Triangle Park, NC 27711; 1995. 2. Kulp, R.N. Update on EPA's Air Duct Cleaning Research Activities. Proceedings of Indoor Environment '97. IAQ Publications, Chevy Chase, MD 20815; 1997; pp. 24-34. 3. NADCA. Mechanical cleaning of non-porous air conveyance system components: standard 1992-01. National Air Duct Cleaners Association. Washington, DC 20005; 1992. 4. Womble, S.E., J.R. Gfirman, and R. Highsmith EPA BASE Program: collecting baseline information on indoor air quality. Proceedings of IAQ5 94: Engineering Indoor Environments. American Society of Heating, Refrigerating and Air- Conditioning Engineers, Inc. Atlanta, GA 30329; 1994. 5. NIOSH. Method 7400 - asbestos and other fibers by PCM. NIOSH Manual of Analytical Methods. Fourth Edition. National Institute for Occupational Safety and Health, Cincinnati, OH 45268; 1994. 6. Wallace, L. Indoor particles: a review. Journal of the Air & Waste Management Association, Pittsburgh, PA 15222; 1996. 46:98-126. 7. Batterman, S. and H. Burge. HVAC systems as emission sources affecting indoor air quality: a critical review. Report No. EPA-600/R-95-014 (NTIS PB95-178596). Environmental Protection Agency. Research Triangle Park, NC 27711; February 1995. 6 ------- 8 Ishikawa, K., T. Iwata, H Ito, K Kumagai, K. Kumura, and S. Yoshizawa. Field investigation on the effectiveness of duct cleaning on indoor air quality with measured results of 1VOC and perceived air quality. Proceedings of Indoor Air '96, the 7th International Conference on Indoor Air Quality and Climate, 1996, Vol. 2, pp. 809- 814. 9. Fanger, P.O. et al. Air pollution source in office and assembly halls, quantified by the olf unit. Energy and Buildings. 1988. Pp. 1-6. 10. A1VC. Duct cleaning - a literature survey. Air Infiltration Review, vol. 14, No. 4, Air Infiltration and Ventilation Centre, Coventry, UK; 1993. 11. EPA. Building air quality: a guide for building owners andfacility managers. EPA- 400/1-91-033 (GPO 055-000-00390-4). U.S. Environmental Protection Agency. Washington, DC 20460. National Institute for Occupational Safety and Health. Washington, DC 20468. 1991. 12. Fugler, D and M Auger. A first look at the effectiveness of residential duct cleaning. Proceedings of the 87th Annual Meeting & Exhibition. Air & Waste Management Association. Pittsburgh. PA 15222; 1994. 13. Van Osdell, D.W., Foarde, K.K.. Fortmann, R.C., and Kulp, R.N. Pilot Air Conveyance System Design, Characterization, and Cleaning. Proceedings of Engineering Solutions to Indoor Air Quality Problems. Air & Waste Management Association. Pittsburgh, PA 15222; 1997, 7 ------- NRMRL-RTP-P-249 TECHNICAL REPORT DATA (Please read Instructions on the reverse before con EPA/600/A-98/026 2. PB98-140254 4. TITLE AND SUBTITLE Evaluating Residential Air Duct Cleaning and IAQ: Results of a Field Study Conducted in Nine Single Family Dwellings 5. REPORT DATE 6. PERFORMING ORGANIZATION CODE 7-authorss) R.Kuip (EPA); R.Fortmann and C.Gentry (Acurex); D. VanOsdell andK.Foarde (RTI); and T.Bebert, R.Krell, and C. Cochrane (NADCA) 8. PERFORMING ORGANIZATION REPORT NO. 9, PERFORMING ORGANIZATION NAME AND ADDRESS A curex Environmental Corp., RTP, NC Research Triangle Institute, RTP, NC National Air Duct Cleaners Assn, Washington, 10. PROGRAM ELEMENT NO. DC 11. CONTRACT/GRANT NO, 68-D4-0005 (Acurex), CR82- 12.SPONSORING AGENCY NAME AND ADDRESS EPA, Office of Research and Development Air Pollution Prevention and Control Division Research Triangle Park, NC 27711 13. TYPE OF REPORT AND PERIOD COVERED Published paper; FY95-9G 14. SPONSORING AGENCY CODE EPA/600/13 1S.supplementary notes appcd project officer is Russell M. Kulp. Mail Drop 54, 541-7980. Presented at IAQ'97, Washington, DC, 9/27-10/2797. 919/ 16. abstract,j-ke paper gives results of a nine-home field study of the impact of mechan- ical air duct cleaning (ADC) methods on indoor air quality (IAQ) and system perfor- mance. ADC services were provided by the National Air Duct Cleaners Association (NADCA). Only mechanical ADC methods were evaluated. Surface treatments, such as biocides or encapsulants, were not part of the study. Pre- and post-ADC measure ments were used to evaluate the impacts. These included deposited duct dust mea- surements, airborne particle and fiber concentrations, microbial bioaerosol and surface sampling, and system performance factors such as temperature, relative humidity, air flow rates, and static pressure. Surface sampling in ducts indicated that mechanical ADC is effective in removing adhered dust and dirt. The particle measurement data could not offer a clear indication that indoor levels can be reduced using mechanical ADC because there was an apparent strong influence from outdoor particle mass concentrations. Mechanical ADC did not significantly reduce bioaero- sol or microbial density in the houses studied. Measurements of system performance factors suggest that ADC may have a positive effect. Supply air rates increased be- tween 4 and 32% in eight of the houses, and return air flow rates increased between 14 and 38% in two of the houses. 17. KEY WORDS AND DOCUMENT ANALYSIS a. DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group Pollution Particles Residential Buildings Ducts Fibers Ventilation Aerosols Cleaning Dust Pollution Control Stationary Sources Indoor Air Quality (IAQ) Particulate Bioaerosols 13 B 14 G 13 M 13K HE 13 A 07D 13H UG 18. DISTRIBUTION STATEMENT Release to Public 19. SECURITY CLASS (This Report} Unclassified 21. NO. OF PAGES 20. SECURITY CLASS (This page} Unclassified 22. PRICE EPA Form 2220 \ (9-73) REPRODUCED BY: NTIS. U.S. Department of Commerce - National Technical Information Service ------- |