Bill W. Bogan

Air Quality Monitoring and On-Site Computer System for Livestock and Poultry Environment Studies

This article reviews the development of agricultural air quality (AAQ) research on livestock and poultry environments, summarizes various measurement and control devices and the requirements of data acquisition and control (DAC) for comprehensive AAQ studies, and introduces a new system to meet DAC and other requirements. The first experimental AAQ study was reported in 1953. Remarkable progress has been achieved in this research field during the past decades. Studies on livestock and poultry environment expanded from indoor air quality to include pollutant emissions and the subsequent health, environmental, and ecological impacts beyond the farm boundaries. The pollutants of interest included gases, particulate matter (PM), odor, volatile organic compounds (VOC), endotoxins, and microorganisms. During this period the research projects, scales, and boundaries continued to expand significantly. Studies ranged from surveys and short-term measurements to national and international collaborative projects. While much research is still conducted in laboratories and experimental facilities, a growing number of investigations have been carried out in commercial livestock and poultry farms. The development of analytical instruments and computer technologies has facilitated significant changes in the methodologies used in this field. The quantity of data obtained in a single project during AAQ research has increased exponentially, from several gas concentration samples to 2.4 billion data points. The number of measurement variables has also increased from a few to more than 300 at a single monitoring site. A variety of instruments and sensors have been used for on-line, real-time, continuous, and year-round measurements to determine baseline pollutant emissions and test mitigation technologies. New measurement strategies have been developed for multi-point sampling. These advancements in AAQ research have necessitated up-to-date systems to not only acquire data and control sampling locations, but also monitor experimental operation, communicate with researchers, and process post-acquisition signals and post-measurement data. An on-site computer system (OSCS), consisting of DAC hardware, a personal computer, and on-site AAQ research software, is needed to meet these requirements. While various AAQ studies involved similar objectives, implementation of OSCS was often quite variable among projects. Individually developed OSCSs were usually project-specific, and their development was expensive and time-consuming. A new OSCS, with custom-developed software AirDAC, written in LabVIEW, was developed with novel and user-friendly features for wide ranging AAQ research projects. It reduced system development and operational cost, increased measurement reliability and work efficiency, and enhanced quality assurance and quality control in AAQ studies.

The National Air Emissions Monitoring Study: Overview of Barn Sources

The National Air Emissions Monitoring Study (NAEMS) is required by a U.S. EPA air consent agreement, in which livestock producers agreed to collect air emission data in exchange for more time to report their emissions and apply for any necessary permits. Field measurement of livestock air emissions is a major part of the study. Compared with most previous field studies of barn air quality, the NAEMS was designed to have 1) several pollutants measured simultaneously including particulate matter (PM), ammonia (NH3), hydrogen sulfide (H2S), and non-methane volatile organic compounds (NMVOC), 2) a long duration of two years, 3) a large number of measured barns (38) using the same protocol, 4) careful selection of farms to enhance their representativeness, and 5) a high level of quality assurance and quality control as required by the U.S. EPA, which is supervising the study. The NAEMS is collecting continuous air emission data from 38 barns at five dairies, five pork production sites, three egg layer operations, one layer manure shed, and one broiler facility for a period of 2 years starting in 2007. At each barn monitoring site, an on-farm instrumentation shelter houses equipment for measuring pollutant concentrations at representative barn air inlets and outlets, barn airflows, operational processes, and environmental variables. A multipoint gas sampling system delivers selected air streams to gas analyzers. Mass PM concentrations are measured at one representative exhaust location per barn using real-time monitors. Motion sensors monitor activity of animals, workers and vehicles. Building ventilation rate is assessed by monitoring fan operation and building static pressure in mechanically ventilated barns, and air velocities through ventilation openings in naturally-ventilated buildings. Data is logged every 15 and 60 s and retrieved with network-connected PCs, formatted, validated, processed, and delivered to the U.S. Environmental Protection Agency (EPA).

Ventilation rates in large commercial layer hen houses with two-year continuous monitoring.

1. Ventilation controls the indoor environment and is critical for poultry production and welfare. Ventilation is also crucial for assessing aerial pollutant emissions from the poultry industry. Published ventilation data for commercial layer houses have been limited, and are mostly based on short-term studies, mainly because monitoring airflow from large numbers of fans is technically challenging. 2. A two-year continuous ventilation monitoring trial was conducted at two commercial manure belt houses (A and B), each with 250 000 layers and 88 130-cm exhaust fans. All the fans were individually monitored with fan rotational speed sensors or vibration sensors. Differential static pressures across the house walls were also measured. Three fan performance assessment methods were applied periodically to determine fan degradations. Fan models were developed to calculate house ventilations. 3. A total of 693 and 678 complete data days, each containing >16 h of valid ventilation data, were obtained in houses A and B, respectively. The two-year mean ventilation rates of houses A and B were 2·08 and 2·10 m3 h−1 hen−1, corresponding to static pressures of −36·5 and −48·9 Pa, respectively. For monthly mean ventilation, the maximum rates were 4·87 and 5·01 m3 h−1 hen−1 in July 2008, and the minimum were 0·59 and 0·81 m3 h−1 hen−1 in February 2008, for houses A and B, respectively. 4. The two-year mean ventilation rates were similar to those from a survey in Germany and a 6-month study in Indiana, USA, but were much lower than the 8·4 and 6·2 m3 h−1 hen−1 from a study in Italy. The minimum monthly mean ventilation rates were similar to the data obtained in winter in Canada, but were lower than the minimum ventilation suggested in the literature. The lower static pressure in house B required more ventilation energy input. The two houses, although identical, demonstrated differences in indoor environment controls that represented potential to increase ventilation energy efficiency, and reduce carbon footprints and operational costs.

Large scale application of vibration sensors for fan monitoring at commercial layer hen houses.

Continuously monitoring the operation of each individual fan can significantly improve the measurement quality of aerial pollutant emissions from animal buildings that have a large number of fans. To monitor the fan operation by detecting the fan vibration is a relatively new technique. A low-cost electronic vibration sensor was developed and commercialized. However, its large scale application has not yet been evaluated. This paper presents long-term performance results of this vibration sensor at two large commercial layer houses. Vibration sensors were installed on 164 fans of 130 cm diameter to continuously monitor the fan on/off status for two years. The performance of the vibration sensors was compared with fan rotational speed (FRS) sensors. The vibration sensors exhibited quick response and high sensitivity to fan operations and therefore satisfied the general requirements of air quality research. The study proved that detecting fan vibration was an effective method to monitor the on/off status of a large number of single-speed fans. The vibration sensor itself was

Using CAPECAB to Process Emission Data in the National Air Emissions Monitoring Study

2 more expensive than a magnetic proximity FRS sensor but the overall cost including installation and data acquisition hardware was

Ammonia and Hydrogen Sulfide Emissions from Naturally Ventilated Free-Stall Dairy Barns

77 less expensive than the FRS sensor. A total of nine vibration sensors failed during the study and the failure rate was related to the batches of product. A few sensors also exhibited unsteady sensitivity. As a new product, the quality of the sensor should be improved to make it more reliable and acceptable.

Air Quality Monitoring and Data Acquisition for Livestock and Poultry Environment Studies

CAPECAB (Calculation of Air Pollutant Emissions from Confined Animal Buildings) is customized software used in the National Air Emissions Monitoring Study (NAEMS) as an efficient data processing tool that reduces data storage space, provides a user-friendly interface to review and process data, and most importantly, aids in producing quality-assured emission data from livestock and poultry facilities. CAPECAB was originally developed in 2003 and has since been used in data processing for numerous livestock-emission projects. For the NAEMS, CAPECAB underwent significant improvements to allow for multiple methods of data review and data validation/invalidation, as well as faster processing speed overall. CAPECAB stores all data for a site in a binary database, which greatly reduces the storage space compared with traditional methods (i.e. spreadsheet files) and enables the user to view one or multiple variables for time ranges spanning from minutes to over one year without manually opening several files. Other features of CAPECAB, such as the user interface, built-in functions (including statistical and histogram features), data validation/invalidation system, and table generation are also discussed in terms of data storage space, quality control, and ease of use.

Large Scale Application of Vibration Sensors for Fan Monitoring at Commercial Layer Hen Houses

Emissions of ammonia (NH3) and hydrogen sulfide (H2S) from two naturally-ventilated freestall dairy barns are presented in this paper. Barn 1 (B1) housed 400 fresh-lactating cows, while Barn 2 (B2) housed 850 non-fresh-lactating cows. The relationships between NH3 and H2S emissions and environmental factors (temperature, wind speed, and relative humidity) were evaluated. Average emissions of NH3 (32.3 g/d-cow) from the smaller B1 were approximately two times as the average emissions (16.6 g/d-cow) from the larger B2. Average emissions of H2S, however, were similar at 2.05 and 1.74 g/d-cow from B1 and B2, respectively. Average emissions of NH3 and H2S were highest in summer (July) at 44.2 and 2.78 g/d-cow from B1, and 23.2 g and 1.92 g/d-cow from B2, respectively. The lowest emissions, on the other hand, were observed in winter (January) at 27.8 and 1.92 g/d-cow from B1, and 10.2 and 0.87 g/d-cow from B2, respectively. In general, emissions of NH3 increased with temperature (R2=0.87) and wind velocity (R2=0.77), while inverse relationships were observed between NH3 emissions and relative humidity (R2=0.84). The correlations between H2S emissions and the same environmental parameters, in general, were poor (R2 = 0.01). Significant spikes of H2S emissions were observed during manure-flushing events.

Fan Monitoring and Ventilation Rate Calculation at Two Large Commercial Layer Barns

The development of analytical instruments and computer technologies in recent decades has facilitated significant changes in the methodologies used in scientific studies of agricultural air quality. A variety of instruments and sensors have been used for long-term and continuous measurements at commercial animal facilities and laboratories for determining baseline pollutant emissions and testing mitigation technologies. New measurement strategies were developed for real-time measurement and multi-location sampling. Optimization of this technology change necessitates an up-to-date system to acquire high-frequency data, control instruments and sampling locations, and monitor system operation. While various air quality research projects involve similar objectives and instrumentation to meet those objectives, they are usually conducted with monitoring plans that differ among sites and among projects. Special data acquisition and control (DAC) hardware and software have to be adapted for each monitoring plan. This paper summarizes various measurement and control devices used for comprehensive air quality studies of livestock and poultry environments. The paper further presents methods for real-time data transformation and processing. It introduces an air quality DAC system, which provided novel, flexible, and user-friendly features. The methodology and technology used in the new DAC system reduces system development and operational cost, increase reliability and work efficiency, and enhances data quality.

Aerial Emission Monitoring at a Dairy Farm in Indiana

Ventilation rate has been a critical factor in the determination of air pollutant emissions from concentrated animal feeding operations (CAFO). In mechanically-ventilated animal buildings with a large number of fans, continuously monitoring the operation of each individual fan can significantly improve the measurement quality for comprehensive air pollutant emission studies such as the National Air Emission Monitoring Study (NAEMS). To monitor the fan operation by detecting the vibration of the fan housing or cone is a newly developed technique. A low-cost electronic vibration sensor has been developed and commercialized for fan monitoring. However, the sensor’s large scale application has not yet been evaluated.