LBNL

The initial solid-phase concentration of volatile organic compounds (VOCs) is a key parameter influencing the emission characteristics of many indoor materials. Solid-phase measurements are typically made using solvent extraction or thermal headspace analysis. The high temperatures and chemical solvents associated with these methods can modify the physical structure of polymeric materials and consequently affect mass transfer characteristics.

LBNL - Proceedings of Indoor Air 2002 (9th International Conference on Indoor Air Quality and Climate) - June 30 - July 5, 2002 - Monterey, California - vol 1, pp 521-526, 3 figs, 10 refs","This paper presents a model for particle deposition on fin-and-tube heat exchangers, that takes into account mechanisms such as impaction, diffusion, gravitational settling and turbulence. Models results are presented and analysed. They agree with experimental data.

A physically based diffusion model is used to evaluate the sink effect of diffusion-controlled indoor materials and to predict the transient contaminant concentration in indoor air in response to several time-varying contaminant sources. For simplicity, it is assumed that the predominant indoor material is a homogeneous slab, initially free of contaminant, and that the air within the room is well mixed.

Age of air is a technique for evaluating ventilation that has been actively used for over 20 years. Age of air quantifies the time it takes for an elemental volume of outdoor air to reach a particular location or zone within the indoor environment. Age of air is often also used to quantify the ventilation effectiveness with respect to indoor air quality. In a purely single zone situation this use of age of air is straightforward, but application of age of air techniques in the general multizone environment has not been fully developed.

This report summarizes the potential for new technologies for ducts, duct fittings, and insulation. It begins with a review of what technology is currently in use or available and found that the only inexpensive ducts in production are insulated wireflex ducts, sheet metal ducts, fiberglass board ducts, and uninsulated plastic ducts. For duct fittings, the market was found to be dominated by sheet metal fittings with some use of ductboard. Fittings that snap together were found for use with steel ducts but are too expensive for a residential setting.

This paper describes the concept of using simulation as a tool for performance validation and energy analysis of HVAC systems. Recent advances in control system technology, including the development of open protocols such as BACnetTM have made sensor and control signal information from various components and subsystems in a building more accessible. This development has created significant potential for improving the monitoring and supervision of building systems in order to optimize operational performance.

The commissioning-related system and house performance improvements and energy savings translate to additional benefits throughout California and beyond. By applying commissioning principles to their work, the building community (builders and contractors) benefit from reduced callbacks and lower warranty costs. HERS raters and inspectors will have access to an expanded market sector. As the commissioning process rectifies construction defects and code problems, building code officials benefit from better compliance with codes.

In this report, we describe what residential commissioning is, its characteristic elements, and how one might structure its process. Our intent in this discussion is to formulate and clarify these issues, but is largely preliminary because such a practice does not yet exist. Subsequent sections of the report describe metrics one can use in residential commissioning, along with the consolidated set of 24 practical diagnostics that the building industry can use now to evaluate them.

A model for predicting the rate at which a volatile organic compound (VOC) is emitted from a diffusion- controlled material is validated for three contaminants (n-pentadecane, n-tetradecane, and phenol) found in vinyl flooring (VF). Model parameters are the initial VOC concentration in the material-phase (C0), the material/air partition coefficient (K), and the material-phase diffusion coefficient (D).

Basic strategy for providing indoor air quality in residences is to dilute indoor sources with outdoor air. This strategy assumes that the outdoor air does not have pollutants at harmful levels or that the outdoor air is, at least, less polluted than the indoor air. When this is not the case, different strategies need to be employed to ensure adequate air quality in the indoor environment. These strategies include ventilation systems, filtration and other measures. These strategies can be used for several types of outdoor pollution, including smog, particulates and toxic air pollutants.