This study explores the potential environmental and energy benefits of using activated carbon fiber (ACF) filters for air cleaning in HVAC systems. The parallel aims for the air cleaning system were to enable reduced indoor exposures to volatile organic compounds (VOCs) and to simultaneously allow reduced rates and energy consumption for outdoor-air ventilation. We evaluated the use of ACF media to adsorb VOCs from indoor air during repeated simulated 12-hour to 24-hour periods of occupancy. In a cyclic regeneration process, VOCs were desorbed from the ACF media and vented outdoors to enable the next cycle of air cleaning. The VOC removal efficiency of the ACF media was measured using a 9.5-cm 2 ACF specimen exposed to a mixture of VOCs that included toluene, benzene, o-xylene, 1-butanol, limonene, undecane and formaldehyde at 29 o C and 30% relative humidity. The concentrations of these model pollutants upstream of the ACF media were in the range 20 to 30 ppb, to simulate realistic conditions.Velocities through the ACF media were typical of those in normal particle filter systems (~0.5 m

Manganese oxide-based catalysts have been synthesized and tested for the abatement of formaldehyde, an ubiquitous indoor pollutant which is not effectively eliminated by most air cleaning technologies. Catalysts were prepared by co-precipitation of MnSO 4 and NaMnO 4 followed by curing at 100, 200 and 400 0 C. Characterization was performed using X-ray diffractometry (XRD), porosimetry, scanning electron microscopy (SEM), and inductively coupled plasma -mass spectrometry (ICP-MS). Diffractograms Research Highlights:). Due to the relatively low costs of synthesis and deployment of these catalysts, this technology is promising for maintaining low indoor formaldehyde levels, enabling energy-saving reductions of building ventilation rates.Synthesis of manganese oxide-based catalysts to remove indoor formaldehyde; High surface area and porosity; Small crystal size; Complete mineralization of formaldehyde;High activity maintained after processing up to 400 m 3 of formaldehyde-laden air.

Field measurements suggest that California retail stores were well ventilated relative to the minimum ventilation rate requirement specified in the Building Energy Efficiency Standards Title 24. Concentrations of formaldehyde found in retail stores were low relative to levels found in homes but exceeded the most stringent chronic health guideline. Looking ahead, California is mandating zero energy commercial buildings by 2030. To reduce the energy use from building ventilation while maintaining or even lowering formaldehyde in retail stores, effective formaldehyde source control measures are vitally important.

This paper focuses on the evaluation of the potential to use a cerium-doped titania photocatalyst activated by visible light to destroy volatile organics. Toluene is the model compound employed to test the photocatalyst, which is coated on the inner surface of an annular plug flow reactor. Mass transfer resistances are present and considered. Experiments were conducted over a range of residence times between 1 and 20 s and toluene concentrations between 150 and 600 ppb using constant visible-light intensity at room temperature. It is shown that the reaction kinetics can be approximated by a first-order expression with a reaction rate coefficient of 1.72 ( 0.015 s -1 . The water adsorption coefficient was found to be 2.64 m 3 /mol. The catalyst also demonstrates mechanical and chemical stability during the course of the experiments conducted. These results indicate that the cerium based titania catalytic surfaces can be considered for application to destruction of volatile organic hydrocarbons in air using a visible light source.

A design for a Quartz Crystal Microbalance (QCM) setup for use with viscous liquids at temperatures of up to 300 °C is reported. The system response for iron and gold coated QCM crystals to two common lubricant base oils, polyalphaolefin and halocarbon, is reported, yielding results that are consistent with theoretical predictions that incorporate electrode nanoscale surface roughness into their analysis.