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CAN SORBENT-BASED GAS PHASE AIR CLEANING FOR VOCS SUBSTITUTE FOR VENTILATION IN COMMERCIAL BUILDINGS?

Description: This paper reviews current knowledge about the suitability of sorbent-based air cleaning for removing volatile organic compounds (VOCs) from the air in commercial buildings, as needed to enable reductions in ventilation rates and associated energy savings. The principles of sorbent air cleaning are introduced, criteria are suggested for sorbent systems that can counteract indoor VOC concentration increases from reduced ventilation, major findings from research on sorbent performance for this application are summarized, and related priority research needs are identified. Major conclusions include: sorbent systems can remove a broad range of VOCs with moderate to high efficiency, sorbent technologies perform effectively when challenged with VOCs at the low concentrations present indoors, and there is a large uncertainty about the lifetime and associated costs of sorbent air cleaning systems when used in commercial buildings for indoor VOC control. Suggested priority research includes: experiments to determine sorbent system VOC removal efficiencies and lifetimes considering the broad range and low concentration of VOCs indoors; evaluations of in-situ regeneration of sorbents; and an updated analysis of the cost of sorbent air cleaning relative to the cost of ventilation.
Date: August 1, 2007
Creator: Fisk, William & Fisk, William J.
Partner: UNT Libraries Government Documents Department

Further development of the cleanable steel HEPA filter, cost/benefit analysis, and comparison with competing technologies

Description: We have made further progress in developing a cleanable steel fiber HEPA filter. We fabricated a pleated cylindrical cartridge using commercially available steel fiber media that is made with 1 {mu}m stainless steel fibers and sintered into a sheet form. Test results at the Department of Energy (DOE) Filter Test Station at Oak Ridge show the prototype filter cartridge has 99.99% efficiency for 0.3 {mu}m dioctyl phthalate (DOP) aerosols and a pressure drop of 1.5 inches. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned using reverse air pulses. Our analysis of commercially optimized filters suggest that cleanable steel HEPA filters need to be made from steel fibers less than 1 {mu}m, and preferably 0.5 {mu}m, to meet the standard HEPA filter requirements in production units. We have demonstrated that 0.5 {mu}m steel fibers can be produced using the fiber bundling and drawing process. The 0.5 {mu}m steel fibers are then sintered into small filter samples and tested for efficiency and pressure drop. Test results on the sample showed a penetration of 0.0015% at 0.3 {mu}m and a pressure drop of 1.15 inches at 6.9 ft/min (3.5 cm/s) velocity. Based on these results, steel fiber media can easily meet the requirements of 0.03% penetration and 1.0 inch of pressure drop by using less fibers in the media. A cost analysis of the cleanable steel HEPA filter shows that, although the steel HEPA filter costs much more than the standard glass fiber HEPA filter, it has the potential to be very cost effective because of the high disposal costs of contaminated HEPA filters. We estimate that the steel HEPA filter will save an average of $16,000 over its 30 year life. The additional savings from the clean-up costs resulting from ruptured glass HEPA filters ...
Date: January 1, 1997
Creator: Bergman, W.; Larsen, G.; Lopez, R.; Wilson, K.; Witherell, C. & McGregor, M.
Partner: UNT Libraries Government Documents Department

Filtration theory using computer simulations

Description: We have used commercially available fluid dynamics codes based on Navier-Stokes theory and the Langevin particle equation of motion to compute the particle capture efficiency and pressure drop through selected two- and three- dimensional fiber arrays. The approach we used was to first compute the air velocity vector field throughout a defined region containing the fiber matrix. The particle capture in the fiber matrix is then computed by superimposing the Langevin particle equation of motion over the flow velocity field. Using the Langevin equation combines the particle Brownian motion, inertia and interception mechanisms in a single equation. In contrast, most previous investigations treat the different capture mechanisms separately. We have computed the particle capture efficiency and the pressure drop through one, 2-D and two, 3-D fiber matrix elements.
Date: January 1997
Creator: Bergman, W. & Corey, I.
Partner: UNT Libraries Government Documents Department

Twenty-third DOE/NRC Nuclear Air Cleaning and Treatment Conference

Description: This paper presents the details of the Nuclear Air Cleaning and Treatment Conference held in Buffalo, New York during July 1994. Topics discussed include: nuclear air cleaning codes and standards; waste disposal; particulate filter developments; sampling and monitoring of process and effluent streams; off-gasses from fuel reprocessing; adsorbents and adsorption; accident control and analysis; revised source terms for power plant accidents; and the highlight of the conference concerned operations at the West Valley DOE facility where construction is underway to solidify radioactive wastes.
Date: March 24, 1995
Creator: Bellamy, R. R.; Hayes, J. J. & First, M. W.
Partner: UNT Libraries Government Documents Department

New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy

Description: Approximately ten percent of the energy consumed in U.S. commercial buildings is used by HVAC systems to condition outdoor ventilation air. Reducing ventilation rates would be a simple and broadly-applicable energy retrofit option, if practical counter measures were available that maintained acceptable concentrations of indoor-generated air pollutants. The two general categories of countermeasures are: 1) indoor pollutant source control, and 2) air cleaning. Although pollutant source control should be used to the degree possible, source control is complicated by the large number and changing nature of indoor pollutant sources. Particle air cleaning is already routinely applied in commercial buildings. Previous calculations indicate that particle filtration consumes only 10percent to 25percent of the energy that would otherwise be required to achieve an equivalent amount of particle removal with ventilation. If cost-effective air cleaning technologies for volatile organic compounds (VOCs) were also available, outdoor air ventilation rates could be reduced substantially and broadly in the commercial building stock to save energy. The research carried out in this project focuses on developing novel VOC air cleaning technologies needed to enable energy-saving reductions in ventilation rates. The minimum required VOC removal efficiency to counteract a 50percent reduction in ventilation rate for air cleaning systems installed in the HVAC supply airstream is modest (generally 20percent or less).
Date: October 27, 2010
Creator: Sidheswaran, Meera; Destaillats, Hugo; Sullivan, Douglas P. & Fisk, William J.
Partner: UNT Libraries Government Documents Department

Saving energy and improving IAQ through application of advanced air cleaning technologies

Description: In the future, we may be able use air cleaning systems and reduce rates of ventilation (i.e., reduce rates of outdoor air supply) to save energy, with indoor air quality (IAQ) remaining constant or even improved. The opportunity is greatest for commercial buildings because they usually have a narrower range of indoor pollutant sources than homes. This article describes the types of air cleaning systems that will be needed in commercial buildings.
Date: March 1, 2011
Creator: Fisk, W.J; Destaillats, H. & Sidheswaran, M.A.
Partner: UNT Libraries Government Documents Department

Sorbent-Based Gas Phase Air Cleaning for VOCs in CommercialBuildings

Description: This paper provides a review of current knowledge about the suitability of sorbent-based air cleaning for removing volatile organic compounds (VOCs) from the air in commercial buildings as needed to enable reductions in ventilation rates and associated energy savings. The fundamental principles of sorbent air cleaning are introduced, criteria are suggested for sorbent systems that can counteract indoor VOC concentration increases from reduced ventilation, major findings from research on sorbent performance for this application are summarized, novel sorbent technologies are described, and related priority research needs are identified. Major conclusions include: sorbent systems can remove a broad range of VOCs with moderate to high efficiency, sorbent technologies perform effectively when challenged with VOCs at the low concentrations present indoors, and there is a large uncertainty about the lifetime and associated costs of sorbent air cleaning systems when used in commercial buildings for indoor VOC control. Suggested priority research includes: experiments to determine sorbent system VOC removal efficiencies and lifetimes considering the broad range and low concentration of VOCs indoors; evaluations of in-situ regeneration of sorbents; and an updated analysis of the cost of sorbent air cleaning relative to the cost of ventilation.
Date: May 1, 2006
Creator: Fisk, William J.
Partner: UNT Libraries Government Documents Department

Evaluation of self-contained HEPA filter

Description: This paper presents the results of an evaluation of a self-contained high-efficiency particulate air filter (SCHEPA) used in nuclear applications. A SCHEPA consists of filter medium encapsulated in a casing that is part of the system boundary. The SCHEPA filter serves as a combination of filter housing and filter. The filter medium is attached directly to the casing using adhesive as a bonding agent. A cylindrical connection in the middle of the end caps connects the filter assembly to adjoining ductwork. The SCHEPA must perform the functions of a filter housing, filter frame, and filter. It was recognized that the codes and standards do not address the SCHEPA specifically. Therefore, the investigation evaluated the SCHEPA against current codes and standards related to the functional requirements of an air-cleaning system. The specific standards used are required by DOE Order 6430.1A and include ASME N509, ASME N510, ERDA 76-21, MIL-F-51068F, NFPA 90A, and NFPA 91. The evaluation does not address whether the SCHEPA as a standard (off-the-shelf) filter could be upgraded to meet the current code requirements for an air-cleaning unit. The evaluation also did not consider how the SCHEPA was used in a system (e.g., whether it was under positive or negative pressure or whether it served as an air inlet filter to prevent contamination releases under system pressurization). The results of the evaluation show that, the SCHEPA filter does not meet design, fabrication, testing, and documentation requirements of ASME N509 and ASME N510. The paper will identify these deficiencies. Specific exhaust system requirements and application should be considered when an evaluation of the SCHEPA filter is being performed in existing systems. When new designs are being contemplated, other types of HEPA filter housings can be used in lieu of the SCHEPA filter.
Date: June 1, 1994
Creator: Arndt, T. E.
Partner: UNT Libraries Government Documents Department

In-place HEPA filter penetration test

Description: We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in- place penetration test is practical.
Date: January 1, 1997
Creator: Bergman, W.; Wilson, kK.; Elliott, J.; Bettencourt, B. & Slawski, J.W.
Partner: UNT Libraries Government Documents Department

Potential for Hepa filter damage from water spray systems in filter plenums

Description: The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for HEPA filter damage during fires has also occurred in the field. Afire in a four-stage, HEPA filter plenum at Rocky Flats in 1980 caused the first three stages of HEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenum , additional studies are required to confirm unequivocally that DOE`s critical facilities are at risk.
Date: January 1, 1997
Creator: Bergman, W.; Fretthold, J.K. & Slawsld, J.W.
Partner: UNT Libraries Government Documents Department

Uncertainty in in-place filter test results

Description: Some benefits of accounting for uncertainty in in-place filter test results are explored. Information the test results provide relative to system performance acceptance limits is evaluated in terms of test result uncertainty. An expression for test result uncertainty is used to estimate uncertainty in in-place filter tests on an example air cleaning system. Modifications to the system test geometry are evaluated in terms of effects on test result uncertainty.
Date: December 31, 1996
Creator: Scripsick, R.C.; Beckman, R.J. & Mokler, B.V.
Partner: UNT Libraries Government Documents Department

DOE standard: Filter test facility quality program plan

Description: This standard was developed primarily for application in US Department of Energy programs. It contains specific direction for HEPA filter testing performed at a DOE-accepted HEPA Filter Test Facility (FTF). Beneficial comments (recommendations, additions, deletions) and any pertinent data that may improve this document should be sent to the Office of Nuclear Safety Policy and Standards (EH-31), US Department of Energy, Washington, DC 20585, by letter or by using the self-addressed Document Improvement Proposal form (DOE F 1300.3) appearing at the end of this document.
Date: February 1, 1999
Partner: UNT Libraries Government Documents Department

Nuclear air cleaning

Description: This report briefly describes the history of the use of high- efficiency particulate air filters for air cleaning at nuclear installations in the United States and discusses future uses of such filters.
Date: December 31, 1994
Creator: Bellamy, R.R.
Partner: UNT Libraries Government Documents Department

Report on Applicability of Residential Ventilation Standards inCalifornia

Description: The California Energy Commission is considering updating its requirements for residential ventilation in the next round of its energy code, known as ''Title 24''. This report contains recommendations for potential changes to the code. These recommendations must be further developed into specific wording before they can be formally considered. Residential ventilation standards always address local and whole-house ventilation rates and some basic source control requirements, but there are many interactions with building systems that must also be considered. McKone and Sherman [8] laid out a set of additional issues that should be addressed before any specific changes to the code should be made. Those key issues included the following: Adventitious Air Flow; Air Distribution; Filtration and Air Cleaning; Occupant Acceptability and Control; Outdoor Air; Peak Demand; Unusual Sources and High-Polluting Events; and Window Operation. McWilliams and Sherman reviewed the literature on residential ventilation and in particular these key issues. They also reviewed codes, standards and guidelines relevant to residential ventilation. That literature serves as the technical basis for this report.
Date: June 1, 2005
Creator: Sherman, Max H. & McWilliam, Jennifer A.
Partner: UNT Libraries Government Documents Department

METAL MEDIA FILTERS, AG-1 SECTION FI

Description: One application of metal media filters is in various nuclear air cleaning processes including applications for protecting workers, the public and the environment from hazardous and radioactive particles. To support this application the development of the ASME AG-1 FI Standard on Metal Media has been under way for more than ten years. Development of the proposed section has required resolving several difficult issues associated with operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality acceptance testing. Performance characteristics of metal media are dramatically different than the glass fiber media with respect to parameters like differential pressures, operating temperatures, media strength, etc. These differences make existing data for a glass fiber media inadequate for qualifying a metal media filter for AG-1. In the past much work has been conducted on metal media filters at facilities such as Lawrence Livermore National Laboratory (LLNL) and Savannah River National Laboratory (SRNL) to qualify the media as High Efficiency Particulate Air (HEPA) Filters. Particle retention testing has been conducted at Oak Ridge Filter Test Facility and at Air Techniques International (ATI) to prove that the metal media meets or exceeds the 99.97% particle retention required for a HEPA Filter. Even with his testing, data was lacking to complete an AG-1 FI Standard on metal media. With funding secured by Mississippi State University (MSU) from National Nuclear Security Administration (NNSA), a research test stand is being designed and fabricated at MSU's Institute for Clean Energy Technology (ICET) Facility to obtain qualification data on metal media. This in turn will support required data needed for the FI Standard. The paper will discuss in detail how the test stand at MSU will obtain the necessary data to complete the FI Standard.
Date: May 23, 2012
Creator: Adamson, D.
Partner: UNT Libraries Government Documents Department

Identifying Sources of Volatile Organic Compounds and Aldehydes in a High Performance Building

Description: The developers of the Paharpur Business Center (PBC) and Software Technology Incubator Park in New Delhi, India offer an environmentally sustainable building with a strong emphasis on energy conservation, waste minimization and superior indoor air quality (IAQ). To achieve the IAQ goal, the building utilizes a series of air cleaning technologies for treating the air entering the building. These technologies include an initial water wash followed by ultraviolet light treatment and biolfiltration using a greenhouse located on the roof and numerous plants distributed throughout the building. Even with the extensive treatment of makeup air and room air in the PBC, a recent study found that the concentrations of common volatile organic compounds and aldehydes appear to rise incrementally as the air passes through the building from the supply to the exhaust. This finding highlights the need to consider the minimization of chemical sources in buildings in combination with the use of advanced air cleaning technologies when seeking to achieve superior IAQ. The goal of this project was to identify potential source materials for indoor chemicals in the PBC. Samples of building materials, including wood paneling (polished and unpolished), drywall, and plastic from a hydroponic drum that was part of the air cleaning system, were collected from the building for testing. All materials were collected from the PBC building and shipped to the Lawrence Berkeley National Laboratory (LBNL) for testing. The materials were pre-conditioned for two different time periods before measuring material and chemical specific emission factors for a range of VOCs and Aldehydes. Of the six materials tested, we found that the highest emitter of formaldehyde was new plywood paneling. Although polish and paint contribute to some VOC emissions, the main influence of the polish was in altering the capacity of the surface to accumulate formaldehyde. Neither the new nor ...
Date: September 20, 2010
Creator: Ortiz, Anna C.; Russell, Marion; Lee, Wen-Yee; Apte, Michael & Maddalena, Randy
Partner: UNT Libraries Government Documents Department

Ozone Removal by Filters Containing Activated Carbon: A Pilot Study

Description: This study evaluated the ozone removal performance of moderate-cost particle filters containing activated carbon when installed in a commercial building heating, ventilating, and air conditioning (HVAC) system. Filters containing 300 g of activated carbon per 0.09 m2 of filter face area were installed in two 'experimental' filter banks within an office building located in Sacramento, CA. The ozone removal performance of the filters was assessed through periodic measurements of ozone concentrations in the air upstream and downstream of the filters. Ozone concentrations were also measured upstream and downstream of a 'reference' filter bank containing filters without any activated carbon. The filter banks with prefilters containing activated carbon were removing 60percent to 70percent of the ozone 67 and 81 days after filter installation. In contrast, there was negligible ozone removal by the reference filter bank without activated carbon.
Date: September 1, 2009
Creator: Fisk, William; Spears, Mike; Sullivan, Douglas & Mendell, Mark
Partner: UNT Libraries Government Documents Department

EVALUATION OF AIR CLEANING SYSTEMS FOR FFTF CONTAINMENT MARGINS

Description: Alternative air cleaning concepts were evaluated for possible application to FFTF containment margins. For evaluation purposes, it was assumed that the air cleaning system must process 3.07 m{sup 3}/s (6500 ACFM) of gas containing sodium compound aerosols (mainly NaOH) at temperatures up to 4070C (7000 F) and pressures up to 0.184 MPa (26.4 psia) and accommodate 5450 kg (12,000 lb) of aerosol material. Three systems designed for 90% efficient removal (a venturi scrubber, a submerged gravel scrubber and a spray scrubber) were compared. The submerged gravel scrubber and the venturi scrubber were rated as prime candidates. Four systems designed for 99% removal efficiency (the two optimum scrubbers chosen for 90% removal efficiency fitted with fibrous elements, a sand and gravel filter and a HEPA filter bank) were compared. The tI~ scrubbers were again rated as prime candidates. Both the sand and gravel filter and the HEPA filter bank were found to be excessively large and costly. Considerable experience supports the use of the optimum scrubber systems and it is concluded that their use is technically feasible for the FFTF containment margins application.
Date: August 1, 1980
Creator: POSTMA, A K. & HILLIARD, R K.
Partner: UNT Libraries Government Documents Department

Comparison of deliverable and exhaustible pressurized air flow rates in laboratory gloveboxes

Description: Calculations were performed to estimate the maximum credible flow rates of pressurized air into Plutonium Process Support Laboratories gloveboxes. Classical equations for compressible fluids were used to estimate the flow rates. The calculated maxima were compared to another`s estimates of glovebox exhaust flow rates and corresponding glovebox internal pressures. No credible pressurized air flow rate will pressurize a glovebox beyond normal operating limits. Unrestricted use of the pressurized air supply is recommended.
Date: October 1, 1994
Creator: Compton, J. A.
Partner: UNT Libraries Government Documents Department

Factors affecting the retention of methyl iodide by iodide-impregnated carbon

Description: Iodide-impregnated activated carbon that had been in use for up to 30 months was studied to characterize those factors that affect its interaction with and retention of methyl iodide. Humidity and competing organic sorbents were observed to decrease the residence time of the methyl iodide on the carbon bed. Additionally, changes in the effective surface area and the loss of iodide from the surface are both important in determining the effectiveness of the carbon for retaining radioactive iodine from methyl iodide. A simple model incorporating both factors gave a fairly good fit to the experimental data.
Date: December 31, 1990
Creator: Hyder, M. L. & Malstrom, R. A.
Partner: UNT Libraries Government Documents Department

A pilot study of energy efficient air cleaning for ozone

Description: A laboratory pilot study has been undertaken with the material that showed the most promise (high capacity and low pressure drop) based on the literature review and associated calculations. The best-performing air cleaner was a commercially available pleated filter that contained a thin layer of small activated carbon particles between two sheets of non-woven fibrous webbing. We will refer to this unit as the ''ozone filter'' although it is marketed for removal of volatile organic compounds (VOCs) from automobile passenger compartments. This pilot study strongly suggests that ozone air cleaning can be practical in commercial air handling systems; however, further tests are needed to assess air cleaner performance under a wider range of conditions.
Date: November 1, 2002
Creator: Gundel, Lara A.; Sullivan, Douglas P.; Katsapov, Gregory Y. & Fisk, William J.
Partner: UNT Libraries Government Documents Department