The department is equipped with a number of environmental chambers for indoor environment research under controlled conditions. The Stainless Steel Environmental Chamber is designed for investigations of emissions of pollutants from indoor sources under very low background pollutant conditions and other related research. This room-sized chamber encloses a volume of 20 m3. All interior surfaces are clad with stainless steel. The synthetic materials used in construction of the chamber were selected, in part, for their low emissions of volatile organic compounds. The chamber is equipped with a single-pass ventilation system equipped with filters to remove particles, volatile organic compounds and ozone. Air enters the chamber through a diffuser positioned high at one end of a long wall and exits the chamber through an outlet located low at the opposite end of the same wall. Air is exhausted outdoors. Ventilation rates can be varied from about 0.1 to 10 air changes per hour (ach). At 1 ach, the variation was ±0.02 ach over a one week period. Air temperature in the chamber can varied from about 15°C to 30°C and held within ±1°C over a period of a week. Relative humidity can also be varied but is usually held at about 50%±1.5%. Air velocity in the chamber is also monitored in the chamber during experiments.
Dual Chamber Facility. The Dual Chamber Facility was constructed of conventional indoor materials to more closely simulate rooms in a building, e.g., with painted wallboard. These chambers, each 15-ft square, are located side-by-side within a building, which permits control of the environment external to the chambers. The facilities have been designed and constructed to permit a variety of modifications necessary to accommodate different experiments. The walls, ceiling and flooring materials can be replaced with other types of materials as needed for experiments and the chambers can be reconfigured. For outdoor pollutant penetration experiments, for example, sections of the chamber walls can be modified to emulate the actual cracks and other openings that exist in real buildings. The chambers are extensively instrumented and have computer-based data acquisition and experimental control capabilities. HVAC system for each chamber are under construction with supply airsteams that can be filtered to remove particles and selected vapors.
Small Chamber Facility. Small chambers of various sizes (3 to 65 Liters), equipped for temperature and humidity control and for variable air flow, are also available for measuring emissions of volatile organic compounds from small samples of materials such as coatings (paints), adhesives, polyurethane foams, etc., under standardized conditions.
Indoor Dispersion Experimental Facility. The Indoor Dispersion Experimental Facility was constructed and equipped for studies of air and pollution transport and dispersion in a large indoor spaces, and evaluation of computational fluid dynamics simulations using advanced experimental techniques. The facility is 7 m x 9m x 11 m high, equipped with an HVAC system and variable position air inlets and is lined with glavanized iron sheets. Measurements of tracer gas plume dispersion are made with a sophisticated computed tomographic system developed in the department, based on tunable diode infra-red lasers using rapid non-intrusive remote open-path sensing.
The Ventilation Research Laboratories in Building 70 are used to develop and evaluate tracer gas analytical methods, to calibrate tracer gas instrumentation, and to assemble gas samplers and other instruments. Tracer gas analytical equipment includes:
The duct research laboratory was organized and constructed for research on building duct systems with respect to energy losses and indoor air quality. It is presently being used to investigate the use of aerosols to seal duct leaks. It is equipped with a duct system in which the flow, pressure and temperature can be controlled. The duct system includes a desiccant-based system for drying the air, as well as continuous humidity measurement equipment. The laboratory is stocked with a collection of duct sections with idealized and realistic leaks. The present set-up also includes a bank of mass flow controllers used for aerosol sampling and control of aerosol production, as well as liquid flowrate and temperature controllers. The sampling equipment includes a cascade impactor and balance for analyzing the aerosol size distribution. In addition, the laboratory equipment includes a video system which is used to continuously record the sealing process. The facility also has frame-grabbing and analysis software, which are used to digitize and analyze the video signals. Its proximity to the Gas Chromatography/Mass Spectrometry Laboratory facilitates research involving chemical analyses.
The Gas Chromatography- Mass Spectrometry (GC-MS) Laboratory is equipped with a Hewlett-Packard Model 5790A capillary gas chromatograph with a UNACON Model 810A (Environchem, Inc.) sample concentrating and inletting system (for vapor analysis) and is interfaced with a Hewlett-Packard Model 5970B Series Mass Spectrometer with a MS DOS operating system and Hewlett-Packard HP G1034C ChemStation software. A NIST/EPA/NIH 75K Mass Spectral Database is part of the system. A UNACON is also available for pre-cleaning the multisorbent samplers used for sampling non-reactive volatile organic compounds. This laboratory is equipped for the preparation of gas phase standards at constant temperature and the safe storage and handling of organic solvents and carcinogens. A second computer with Hewlett-Packard data analysis software system is also located in the same laboratory so that data analysis can be done while the GC/MS is analyzing the next sample.
The Organic Chemical Analysis Laboratory is equipped with a number of chromatographs including a Hewlett-Packard 1090M High Performance Liquid Chromatograph with a DR 5 solvent delivery system, an autosampler-injector (Model HP 798467A), a diode array detector, and heated column compartment, 2 (coupled) HP Model 1046A programmable fluorescence detectors, an HP Model 79994A LC workstation with HP Model 79995A and HP 79988A software packages is also available for this project (a dedicated refrigerated temperature bath is available to maintain the column compartment temperature below ambient temperatures if required); a Hewlett-Packard Model 5890A Series II Gas Chromatograph with a capillary column and injector, N2 cryogenic oven control and a ThermedeTec, Inc. (a TEA Model 543 Analyzer, which is a N-nitrosamine-specific detector, is also available for this instrument); and a Hewlett-Packard Model 5890 gas chromatograph, with a capillary column and a DETector Energy & Technology, Inc. TID-2 nitrogen-phosphorus detector. This instrument is equipped for both gas and syringe injections.
The Department has a dual-processor Silicon Graphics Origin 2000 computer with 768 megabytes of memory, and 10 gigabytes internal disk and a 100 gigabytes external RAID drive. This machine is used for cmputational fluid mechanics modeling, and for input/output processing of simulations on the NERSC Cray machines.
The Department is also equipped with two Hewlett-Packard 9000/735 workstations, each with 80 megabytes of memory, one with 4.5 gigabytes of disk space and a DDS (DAT) tape drive and the other with 1 gigabyte of disk space and an 8-mm tape drive. Their speed of 64 megaflops makes them suitable for numerical and Monte Carlo modeling. The tape drives are also used for backup of both computers.
Significant computational fluid mechanics modeling is also done on Cray multiprocessor SVS computer cluster (each machine giving about 800 megaflops of peak performance per processor), and on a CRAY T3E with a peak performance of 600 gigaflops. These computers are at NERSC which is physically located at the Lawrence Berkeley National Laboratory.
For further information, contact:
William J. Fisk, Department Head
Indoor Environment Department
Environmental Energy Technologies Division
E.O. Lawrence Berkeley National Laboratory
Berkeley, CA 94720
(510) 486-6591