Using ASHRAE 110 hood testing as a TQM tool to improve laboratory fume hood performance.

ANSI/ASHRAE 110-1995, Method of Testing Performance of Laboratory Fume Hoods (ASHRAE 1995) yields quantitative data about fume hood containment and can be used in a classical total quality management (TQM) approach to process improvement. This involves measuring process indicators, analyzing probable causes of poor performance, implementing changes to the process, and again measuring the indicators to determine the efficacy of the changes implemented.

A study on how sash movement affects performance of fume hoods.

This study was conducted to determine how sash movements affect the performance of fume hoods. The performance of two fume hoods was studied as the sashes were moved from closed to open position at speeds of 2 ft/s, 1.5 ft/s, and 1 ft/s. The tests were conducted with fume hoods operated at both constant volume and variable air volume. The tests indicate that sash movements can disturb airflow patterns at the face of the hood and potentially affect the performance of the hood. The effect of the sash movement varied with hood type and speed of sash movement.

Review on using the time constant for studying the atrium smoke filling processes.

A time constant has been proposed to characterize the time it takes to fill an atrium space with smoke for design purposes. This was defined through the use of the empirical equation expressing the mass entrainment rate to the 312 power of the clear height. However, the equation holds only when the flame tip touches the smoke layer, and the flame temperature was taken to be 1100 K (827°C 1521°F).

Evaluation of residential duct sealing effectiveness.

The purpose of this project was to evaluate duct sealing as a means of reducing the energy consumption of hot air distribution systems in central Pennsylvania houses. Five houses were studied, all of which were heated with forced-air electric heat pump systems. During the winter of 1995, the heat pump energy consumption, supply air temperature, and the temperature at the thermostat were monitored continuously for approximately two months prior to the duct retrofit. A test also was performed to measure the leakiness of the ductwork.

Literature review on CO2 based demand controlled ventilation.

Many ventilation requirements and recommendations are in the form of outdoor airflow rates per person. Ventilation systems are therefore designed to provide a minimum level of outdoor air based on the designed occupancy level multiplied by the per-person ventilation requirement. Because the indoor generation rate of carbon dioxide is dependent on the number of occupants, it has been proposed to use indoor carbon dioxide concentrations as a means of controlling outdoor air intake based on the actual number of occupants in the space as opposed to the design occupancy.

Evaluating building IAQ and ventilation with indoor carbon dioxide.

A number of approaches exist to evaluate building ventilation and indoor air quality. In some situations, the measurement and analysis of indoor carbon dioxide concentrations can be useful for understanding indoor air quality and ventilation. On the other hand, oversimplified descriptions of measurement procedures based on carbon dioxide have been presented, and there have been many instances in which indoor carbon dioxide concentration measurements have been misinterpreted and misunderstood.

Derivation of equations necessary for primary airflow redistribution in VAV systems to reduce outdoor air intake while meeting ventilation requirements.

The multiple spaces equation of ASHRAE Standard 62-1989 makes it possible to bring in a smaller fraction of outdoor air than that dictated by the critical space. This paper develops an analytical proof that increasing the primary airflow rate to t e critical space reduces the outdoor airflow rate required to meet ventilation requirements. For systems employing fan-powered boxes, where more than one box is critical, a systematic procedure for incrementally increasing the primary air is currently required.

A study of control strategies to improve indoor air quality with outdoor air in winter in Taiwanese apartments - demonstrated by a design for a bathroom.

Dampness in residential buildings is detrimental to the health of the occupants and causes the growth of mold and decay in the fabric of the building materials. In Taiwan the average winter relative humidity is 80% and the average temperature is 15°C (59°F). It has been found that the average winter indoor moisture content in Taiwanese apartments can be higher than the outdoor content by as much as 15%. Although the main cause for the increased indoor humidity levels has not been identified, removing the moisture generated from shower baths can help reduce the humidity.

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