Quality Assured Measurements of Livestock Building Emissions: Part 4. Building Ventilation Rate

摘要

Standard protocols for sampling and measuring gas, dust and odor emissions from livestock buildings are needed to guide scientists, consultants, and regulators. Recently, two federally funded, multi-state projects have initiated field studies to measure emissions of PM10, TSP, hydrogen sulfide, ammonia, carbon dioxide, methane and volatile organic compounds (VOC) from swine and poultry production buildings. This paper will focus on the quasi-continuous measurement of building ventilation rate from these facilities. Since emission rate is the product of pollutant concentration and exhaust air flow rate, both quantities need to be accurately determined for estimates of pollutant emissions to be valid. As the ventilation exhaust capacity of a mechanically ventilated livestock building may be provided by between 1 and 75 fans, determining ventilation rate at any point in time or cumulatively over a monitoring period is not a trivial task. As part of the data collected during the measurement of pollutant concentration from livestock and poultry production buildings, fan status (on/off) and building static pressure are being recorded. Fan capacity could be taken from manufacturer's fan data or independent fan test data where available. However, it well-known that mechanical condition and degree of maintenance can significantly affect actual fan capacity.