English

The results of a literature survey and an engineering analysis are presented that evaluate the process, technical, and sizing considerations of photocatalytic oxidation (PCO) as a commercial technology to treat (i.e., remove) low-level contaminants in feed streams of air. PCO uses the energy of photons from light sources to activate a catalyst.

This paper introduces an improved model of a honeycomb UV/PCO air purifier that accounts for the combined effects of the nonuniform UV irradiation field resulting from a finite number of lamps and the variation of the local mass transfer coefficient along the honeycomb passages. The model utilizes reaction kinetics equations for common VOCs in humid air. The results of the improved model are compared with published experimental data of the single-pass conversion efficiency of single- and multi-stage reactors for toluene and formaldehyde.

A project completed in 2004 titled Alternatives to Compressor Cooling showed that carefully controlled mechanical ventilation cooling can significantly reduce summer peak load and can eliminate the need for vapor compression cooling in areas between the California coastline
and the central valley. This technology is most applicable in dry climates where vapor compression cooling is needed only a few days of the year and hot, dry climates that have a drybulb

Air distribution is one of the most important factors determining thermal comfort and transport of airborne contaminants in aircraft cabins. Improvement of air quality in such airspaces is limited by the difficulties in simultaneously measuring the air velocity profile within the entire flow field.

Airflow patterns and air velocity within an aircraft cabin have profound effects on the thermal environment and air quality around passengers. To characterize airflows in air cabins experimentally, a full-scale, five-row section of a jumbo aircraft cabin was constructed. Each row had seven passenger seats. The mockup was a wood structure based on the actual dimensions of the Boeing 767 aircraft cabin. Inside the passenger cabin, actual aircraft equipment, including seats, internal

Although the rate of outdoor air (OA) ventilation has a substantial influence on building energy consumption and occupant health, the available data indicate the outdoor air ventilation rates are poorly controlled in many buildings. Technologies being marketed for real-time measurement of the flow rates of outdoor air into HVAC systems should enable better control of OA ventilation. In laboratory research we have studied the performance of these technologies.

Dedicated outdoor air systems (DOAS) are first defined. Then the single-space operating system, whose performance is presented here, is shown to conform to that definition. The controlled components are identified, along with the minimal instrumentation needed for control. Control of each component individually, and in the context of the whole, is presented. Supplemental controls to reduce terminal reheat energy consumption in multi-space applications are developed. Issues

To save energy and comply with the IAQ procedure in ASHRAE Standard 62-1999 or to add protection to occupants and contents in a building, more building owners and facility managers are using gas-phase filtration (GPAFE) in their buildings. However, GPAFE is fraught with questions about changeout schedules, lifetimes, and capture efficiencies, particularly during episodic events. To save money, facility managers try to minimize filter changeout and sometime eliminate the GPAFE filter banks entirely.

Evaluation of the ventilation effect and indoor air quality in ventilated rooms is very important for ventilation system design. Air-exchange efficiency is widely used to indicate ventilation effect and IAQ; however, it does not take into account occupant distribution in the room and thus is limited.

This paper considers the effect of air properties on ammonia levels in the cages and main room space of an animal research facility containing mouse static micro-isolators. The ammonia production from mice is affected by the level of relative humidity (RH) of the air, with higher production rates at elevated RH values. The manipulation of the room supply discharge air, therefore, offers a means of reducing ammonia levels in both the cage and room.