2002 Annual Report
Research
Ventilating Systems for Enhancing Indoor Environmental Quality
Kevin Janni, Professor and Head
Larry Jacobson, Professor
Verlyn Johnson, Information Technology Professional
Funding Source
Minnesota Agricultural Experiment Station
Objective
In Minnesota, most agricultural animals are raised in environmentally-controlled
facilities. Acceptable indoor environmental quality is important for maintaining
human and animal well-being and productivity. Minnesota’s weather
extremes between winter and summer creates the need for ventilating systems
that have a wide range of capabilities. Objectives are to:
- Collect thermal environmental and air quality data in livestock facilities in Minnesota to create a database to evaluate thermal and ventilation models, ventilating system design and management, and building design and management.
- Develop strategies, equipment, and processes for reducing airborne
emissions within and from livestock facilities and their impact on both
indoor and outdoor air quality.
Project Description
Interest in ambient air quality surrounding livestock facilities is growing.
Ambient air quality depends on the amount of dust and gases emitted from
the facilities. A study was conducted to measure emissions of ammonia,
hydrogen sulfide, and particulate matter from one turkey, one swine and
one dairy farm in Minnesota for approximately ten days during cold weather
and ten days during warm weather. Grab dust samples were taken twice each
monitoring period. Odor samples were taken once during the summer monitoring
period. Sites and barns were monitored at or near full capacity and with
near market weight or mature animals, assuming that this would provide
the worst case or highest gas and dust emissions.
Results
Ammonia emissions during the winter months for all three species were similar, ranging from 224 to 273 mg/hr/500 kg live weight for all species. Ammonia emissions during the warm weather were 12,347, 2751, and 481 mg/hr/500 kg live weight for turkey, swine, and dairy respectively. These data were similar to those reported in European literature. The dust data suggests that broilers emit the most inhalable and respirable dust followed by swine and dairy. Respirable dust emissions were far less than inhalable dust emissions in all cases. PM10 emission values were higher in the dairy facility than in either the turkey or swine facilities. Hydrogen sulfide emission rates varied from 5 to nearly 550 µg/hr/m2. Hydrogen sulfide emissions were highest from the swine facility in the winter on both a per animal weight basis and a per area basis. Summer data could not be compared among these facilities because of the limitations of the hydrogen sulfide monitoring equipment. For the turkey and dairy facilities, emissions of hydrogen sulfide were higher during the summer than winter. Emission rates are hard to quantify because it is difficult to measure ventilation rate measurements in naturally ventilated facilities and differences in measurement and sampling methods. Additional study is needed to determine the impact of building design and management on emission rates.