外文翻译--标准62#46;1-2004：系统设置：动态重置操作.doc

9． 翻译 Standard62.1-2004: System Operation: Dynamic Reset Option Seventeen years ago, the ventilation rates established by ANSI/ASHRAE Standard 62-1989, ventilation for Acceptable indoor air quality, increased substantially over those previously required by the 1981 version of the standard. Fifteen years later, standard 62-2004 prescribed new minimum breathing zone ventilation rate and a new calculation procedure to find the minimum intake airflow needed for different ventilation systems. Described in previous articles, these new rates and procedures must be used to find the design or “worst-case” outdoor air intake flow, which establishes the required capacity of mechanical system equipment. In this article, we turn from ventilation system design to operation. Variation in occupancy or ventilation airflow The number of occupants in many ventilation zones changes during normal. Actual zone population often falls short of park design population used to establish the highest zone outdoor airflow and outdoor air intake flow needed. Consequently, standard 62.1 allows breathing zone and/or intake airflow to be reset in response to changes in zone population or the resulting changes in the zone ventilation airflow per person. To reset ventilation based on the current population within a zone requires a reasonably accurate estimate of population or breathing zone outdoor air rate. Standard 62.1 lists four example measures used to estimate variations in occupancy and one measure to estimate variation in ventilation airflow. Direct Count of People. In some zones, occupant entry and exit may be orderly. Using appropriate sensors and counting controls, the difference between entry and exit events can be used to estimate population based on a direct “count”. Ticket sales might also be used as an estimate of population. Some retail stores or auditoriums may be configured to use these approaches. Sensors that actually sense individual occupants also might be used, alt