Progress 10/01/00 to 09/30/05
Outputs
Biofilters are an effective technology for removing odor, hydrogen sulfide and ammonia from air from livestock facilities. This project documented typical odor threshold reductions between 78 and 95%, hydrogen sulfide reductions between 86 and 97%, and ammonia reduction between 50 and 82%. Proper biofilter design is critical to provide effective and economical treatment. Research results were used to develop design guidelines for open-bed biofilters for odor control. Experiments were conducted to evaluate the effectiveness of different biofilter media mixtures. Research results indicated that media mixtures with between 30% and 50% by weight of compost and wood chips between 70% and 50% (by weight) are equally effective reducing odor emissions. Media moisture content is critical to biofilter performance. A relation between unit flow rate through the biofilter media and the unit pressure drop across the media was needed. Two methods of characterizing compost and wood
chip biofilter media (i.e. sieve analysis and five-gallon pail water void analysis) were evaluated and found to have a high correlation coefficient. The five-gallon pail water void can be used in the field. The results are used to evaluate alternative biofilter designs and selecting fans with adequate fan performance characteristics. Biofilters reduce NH3 emissions from 30 to 85%. A study was conducted to determine the forms and quantity of N accumulation. The biofilters averaged 80.4% NH3 removal and had an elimination capacity of 7.6 g/m3/h. Total-N accumulation in the media had equal parts of NH3-N, NO3-N, and organic N. Moisture content affected accumulation of NH3-N and NO3-N but not total-N. Total-N accumulated in the media only accounted for 29% of the N removed. Net NO gas exhausting accounted for a small part of the difference between removed N and media accumulated N. Research was begun to evaluate alternative systems for handling milk house wastewater. Systems were
installed on working dairy farms varying in size from 50-130 cows. All systems have septic tanks with at least 24 hours of detention time. Bark bed systems with pressure distribution were sized based on organic loading rate and hydraulic acceptance of the soil. Irrigation systems required good system drain back and minimal surface runoff. Aerobic systems reduced the biological oxygen demand (BOD) of the wastewater as expected, however wastewater BOD levels were higher than expected. The aerobic systems used were not able to treat the milk house wastewater consistently at three sites to permit discharge. Water flow data collected on 11 farms found flow rates ranged from 95 to 441 gallons per day (gpd) or from 2.9 to 6.4 gpd/cow. Effluent leaving the septic tanks had an average BOD of 2220 mg/L, chemical oxygen demand (COD) of 3360 mg/L, total suspended solids (TSS) of 1030 mg/L, and fats, oils and grease (FOG) of 650 mg/L. BOD levels ranged from 76 to 9400 mg/L with similar variability
in the other parameters. Three farms had significantly higher than average values.
Impacts
Biofiltration is an effective air treatment for reducing gas and odor emissions from mechanically ventilated swine facilities. This research led to the development of design and management guidelines for biofilter, which are being used through out the region. Some local units of government require biofilters on new animal facilities. This research has provided livestock producers with an effective odor control technology. Improper handling of milk house wastewater can negatively impact environmental water quality. Many small and mid-sized dairy operations in Minnesota need to upgrade their milk house wastewater handling systems to comply with Minnesota Feedlot Rules (Minnesota Rules Chapter 7020). Results from this project will provide producers and agency staff with design and performance information on select systems for handling milk house wastewater effluent in an environmentally sound manner in a cold climate.
Publications
- Schmidt, D. R., K. A. Janni, and R. Nicolai. 2004. Biofilter design information. BAEU-18. [Online] p25. Available at http://www.manure.umn.edu/assets/baeu18.pdf.
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Progress 01/01/04 to 12/31/04
Outputs
Biofiltration is an effective air treatment for reducing gas and odor emissions from mechanically ventilated swine facilities. Treating 100% of the ventilating air from a deep-pit swine-finishing barn can be cost prohibitive. Researchers at Iowa State University proposed a strategy to treat a critical minimum amount of ventilation air, which results in a maximum emission control benefit. A study was conducted in Minnesota to evaluate the critical minimum biofilter ventilation strategy on a tunnel ventilated deep-pit swine finishing barn. It was hypothesized that a barn with the critical minimum ventilating rate will have reduced gas and odor emissions compared to a control tunnel ventilated deep-pit swine finishing barn with standard pit ventilating rates. Emissions from a mechanical ventilated, 2000 head pig-finishing barn with pit fans in southern, MN was monitored for approximately 6 weeks. The barn was a double-wide barn with two 1000 head side-by-side rooms. The
existing ventilating system provided about 25 cubic feet per minute per pig (CFM/pig) of airflow through the manure storage pit and biofilters. One room was supplemented with two additional pit exhaust fans that provided another 20,000 CFM for a total of 45 CFM/pig of pit airflow. Both rooms had four tunnel ventilation fans located at one end of the building that provided about 70,000 CFM of airflow (airflows for each fan were measured with an on site fans measurement system). A mobile lab capable of semi continuously measuring emission of hydrogen sulfide and ammonia was set up at the site in early August and data collection started at that time. Weekly odor samples were collected starting in late August through mid-September. Data analysis is continuing. Work continues on the environmental assessment and control of milk house wastewater from dairy facilities. The purpose of this project is to demonstrate and evaluate alternative systems for treating milk house wastewater. A
multi-agency effort is guiding and funding the project to install eight demonstration systems and monitor their performance for two years. The systems were installed on working dairy farms varying in size from 50-130 cows. All of the wastewater systems have a septic tank with at least 24 hours of detention time. The septic tanks are emptied once or twice per year. Two systems use bark beds with pressure distribution. The bark beds were sized based on both organic loading rate and hydraulic acceptance of the soil. Poor wastewater distribution at one site, which caused some surfacing and system leakage, was corrected. The bark bed systems have worked well. The irrigation system has worked well through cold weather. Good system drain back and minimal surface runoff is required. The aerobic systems reduced the biological oxygen demand (BOD) of the wastewater as expected, however wastewater BOD levels were higher than expected. The aerobic systems used were not able to treat the milk house
wastewater consistently at three sites to permit discharge. Monitoring and data analysis continues.
Impacts
Biofiltration is an effective air treatment for reducing gas and odor emissions from mechanically ventilated swine facilities. If the critical minimum concept can be demonstrated to be effective, swine producers may build smaller biofilters and still get sufficient emission control. The smaller biofilters will reduce air treatment system costs and improve profitability. Improper handling of milk house wastewater can negatively impact environmental water quality. Many small and mid-sized dairy operations in Minnesota need to upgrade their milk house wastewater handling systems to comply with Minnesota Feedlot Rules (Minnesota Rules Chapter 7020). Results from this project will provide producers and agency staff with design and performance information on options for handling milk house wastewater effluent in an environmentally sound manner in a cold climate.
Publications
- Guo, H., Jacobson, L.D., Schmidt, D.R., Nicolai, R.E. and Janni, K.A. 2004. Comparison of five models for setback distance determination from livestock sites. Canadian Biosystems Engineering 46(6):17-25.
- Christopherson, S.H., Schmidt, D.R. and Janni, K.A. 2004. Evaluation of aerobic treatment units in treating high strength waste from dairy milk houses. IN: Proc. 10th National Sym on Individual and Small Community Sewage Systems Conf., Ed. K. R. Mankin. ASAE, St. Joseph, MI. pp 172-175.
- Christopherson, S.H., Schmidt, D.R., Bilotta, J. and Janni, K.A. 2004. Dairy milk house wastewater treatment research and demonstration project: project overview. [Online] p2. Available at http://www.bae.umn.edu/extens/milkhouse/overview.pdf
- Schmidt, D.R., Christopherson, S.H., Bilotta, J. and Janni, K.A. 2004. Dairy milk house wastewater treatment research and demonstration project: irrigation system. [Online] p1. Available at http://www.bae.umn.edu/extens/milkhouse/irrigation.pdf
- Christopherson, S.H., Schmidt, D.R., Bilotta, J. and Janni, K.A. 2004. Dairy milk house wastewater treatment research and demonstration project: aerobic treatment systems. [Online] p2. Available at http://www.bae.umn.edu/extens/milkhouse/aerobic.pdf
- Christopherson, S.H., Schmidt,D.R., Bilotta, J. and Janni, K.A. 2004. Dairy milk house wastewater treatment research and demonstration project: bark bed treatment systems. [Online] p2. Available at http://www.bae.umn.edu/extens/milkhouse/barkbed.pdf
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Progress 01/01/03 to 12/31/03
Outputs
This project began working on the environmental assessment and control of milk house wastewater from dairy facilities. The purpose is to demonstrate and evaluate alternative systems for handling milk house wastewater. A multi-agency effort is guiding and funding the project to construct eight demonstration systems and monitor their performance for two years. Seven systems were installed Fall 2001 and one system was installed in 2002. The systems were installed on working dairy farms varying in size from 50-130 cows. Water flow data was collected on 11 farms for one year prior to wastewater system design and installation. Water flow rates ranged from 95 to 441 gallons per day (gpd) or from 2.9 to 6.4 gpd/cow. A biological oxygen demand (BOD5) of 1100 mg/L was used in the design to represent typical BOD5 levels leaving a septic tank based on five samples from participating farms. Preliminary analysis of effluent leaving the septic tanks in the project had an average
BOD5 of 2220 mg/L, chemical oxygen demand (COD) of 3360 mg/L, total suspended solids (TSS) of 1030 mg/L, and fats, oils and grease (FOG) of 650 mg/L. BOD5 levels ranged from 76 to 9400 mg/L with similar variability in the other parameters. Three farms had significantly higher than average values. All of the wastewater systems have a septic tank with at least 24 hours of detention time. The septic tanks are emptied once or twice per year. Two systems use bark beds with pressure distribution to treat the septic tank effluent. The beds were sized based on both organic loading rate and hydraulic acceptance of the soil. The two bark bed systems were placed in wooded areas to avoid using cropland. They have worked without a problem. Water samples from within the beds have not yielded sufficient quantities for analysis. Three types of aerobic treatment units (ATU) are being used. In the fall of 2002, four commercial ATUs, two of each type, were installed at four dairy farms. These systems
were designed with a surface discharge goal of 25 mg/L BOD5. In 2003 a third type of ATU was installed in a system to discharge through a drip irrigation field. The first two types of ATUs had removal efficiencies early in the study for BOD5, COD, TSS, and FOG ranged from 44-94%, 32-94%, 61-82%, and 71-98%, respectively. The higher than expected wastewater strength may require management changes or system redesigns to achieve the design discharge goals. The irrigation system surface applies the septic tank effluent to a filtration/infiltration area. Two types of irrigation heads were used. An impact head was used in warm weather. Four "wobbler" heads, which are more resistant to freezing, were used in cold weather. Effluent is applied at agronomic rates. The irrigation system did experience some freezing and odor issues but continued to operate through the first winter. The average equipment and installation cost was nearly $10,000 for the eight systems with a range of $6,200 -
$14,400. Cost sharing, experience, and non-research situations are expected to reduce out of pocket costs to producers.
Impacts
Improper handling of milkhouse wastewater can negatively impact environmental quality. Many small and mid-sized dairy operations in Minnesota need to upgrade their milk house wastewater handling systems to comply with Minnesota Feedlot Rules (Minnesota Rules Chapter 7020). Producers need systems that perform reliably, meet environmental regulations, fit their management practices, and are economical to install and operate. Results from this project will demonstrate and document options for handling milkhouse wastewater effluent in an environmentally sound manner in a cold climate. Outreach efforts will provide producers, engineers, Extension educators, and technical staff practical and technical information on the systems used in the study. Performance, cost, and management information gathered will be disseminated statewide.
Publications
- Christopherson, S., D.R. Schmidt, K.A. Janni and J. Zhu. 2003. Evaluation and Demonstration of Treatment Options for Dairy Parlor and Milk House Wastewater. ASAE Paper No. 034121. ASAE, St. Joseph, MI 49085.
- Lazarus, W.F., K.A. Janni and J.K. Reneau. 2003. Economics of successful stall barn modernization. IN: Proc. Fifth Int. Dairy Housing Conf., ASAE, St. Joseph, MI. pp. 117-124.
- Allen, D.M., J.G. Linn and K.A. Janni. 2003. Thermal environmental effects on feed intake in commercial dairy herds. IN: Proc. Fifth Int. Dairy Housing Conf., ASAE, St. Joseph, MI. pp. 205-212.
- Bicudo, J.R., K.A. Janni, L.D. Jacobson and D.R. Schmidt. 2003. Odor and hydrogen sulfide emission from a dairy manure storage. IN: Proc. Fifth Int. Dairy Housing Conf., ASAE, St. Joseph, MI. pp. 368-375.
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Progress 01/01/02 to 12/31/02
Outputs
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. 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 micrograms/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. Biofilters have been shown to reduce NH3 emissions from 30 to 85%. Research was conducted to determine the forms and quantity of N accumulation in a compost and wood chip media mixture. Bench-scale biofilters operated at a 5 s empty bed contact time, 15 ppmv NH3 inlet concentration, two operating temperatures (12 C and 22 C) and three media moisture contents (40%, 50%, and 60% wb) were monitored. All biofilters averaged 80.4% NH3 removal and had an elimination capacity of 7.6 g/m3/h. Total-N accumulation in the media was composed of equal parts of NH3-N, NO3-N, and organic N. Moisture content affected accumulation of NH3-N and NO3-N but not total-N. Temperature was not a significant factor for N accumulation, whereas biofilter depth and time were. Total-N accumulated in the media only accounts for 29% of the N removed by the biofilter after 1160 h. Net NO gas
exhausting accounts for a small part of the difference between removed N and media accumulated N. The fate of N remains unknown, but micro-site denitrification may explain some of the discrepancy.
Impacts
Airborne dust and gases in livestock facilities can impact both human and animal health and the ambient air quality surrounding livestock facilities. Ambient air quality is a function of the amount of dust and gases emitted from the facilities and the downwind transport and transformation of these constituents. Environmental regulatory agencies at both the state and local level are reviewing emissions of gases and dust from livestock facilities to determine whether or not these facilities 1) violate current air emission standards, or 2) have a significant impact on ambient air quality. The results of this work will help regulatory agencies make their determination. The biofilter results help document the environmental impact and our understanding of biofilters. Biofilter design and management guidelines are available. Several livestock facilities in Minnesota are using biofilters.
Publications
- Schmidt, D.R., Jacobson, L.D., Janni, K.A. 2002. Continuous monitoring of ammonia, hydrogen sulfide and dust emissions from swine, dairy and poultry barns. ASAE Paper No. 024060. ASAE, St. Joseph, MI 49085.
- Nicolai, R.E., Clanton, C.J., Janni, K.A. 2002. Ammonia removal and nitrogen accumulation in biofilter media. IN: Proc. of Fifth Int. USC - TRG Conference on Biofiltration. pp. 119-129. October 31-November 1, 2002. Newport Beach, CA.
- Janni, K. 2002. Upgrading and modernizing dairy facilities and manure handling. Minnesota Dairy Days 2002. Dept. of Animal Science, University of Minnesota, St. Paul, MN. 87 p.
- Janni, K., Jacobson, L.D., Schmidt, D.R., Norlien, K. and Rosenstein,T. 2002. Livestock and Poultry Odor Workshop. Dept. of Biosystems and Agricultural Engineering, Univ. of Minnesota, St. Paul, MN, 197 p.
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Progress 01/01/01 to 12/31/01
Outputs
Odors from livestock operations are a growing concern as residential developments encroach on traditional agricultural regions. County and other local units of government are being asked to make land use decisions to reduce the impact of odors from livestock and poultry operations, but with little or no scientific information and few tools on which to base their decisions. Setbacks between feedlots and neighboring residences are commonly used to minimize odor impacts. A geographical information system (GIS) was used to present and query the spacial data for two study areas in Minnesota. Setback distances were calculated using Odors from Feedlots Setback Estimation Tool (OFFSET). The project demonstrated the use of GIS to map setback distances from OFFSET. The GIS maps were useful for communicating setback distances. Query results provided useful information for evaluating the impact of feedlot odor emissions. The results from the two study areas indicated that total
feedlot odor emissions, location, and the percent annoyance free level required affected the number of residences and public areas impacted by one or more feedlots. GIS can also be used to identify potential feedlot sites. Biofilters are an effective technology for removing odor, hydrogen sulfide and ammonia from air from livestock facilities. Proper biofilter design is critical to provide effective and economical treatment. Based on previous work compost and wood chip media mixtures ranging from 30:70 to 50:50 percent by weight were recommended for removing odors and hydrogen sulfide from livestock wastes. To improve the biofilter design process the relation between unit flow rate through the biofilter media and the unit pressure drop across the media is needed. The purpose of this project was to develop a method for characterizing compost and wood chip mixtures and predicting the relation between flow rate and pressure drop. Two methods of characterizing compost/wood chip biofilter
media (i.e. sieve analysis and five-gallon pail water void analysis) were evaluated and found to have a high correlation coefficient. Relations to estimate the unit pressure drop given the unit flow rate and percent voids were developed for media with between 40 to 60% voids. These can be used to evaluate alternative biofilter designs and for selecting fans with adequate fan performance characteristics.
Impacts
The combining of Geographical Information Systems (GIS) and Odors from Feedlots Setback Estimation Tool (OFFSET) produced a powerful method for communicating setback distances. This method helps livestock producers make management decisions and county and other local government officials to make land use decisions. The biofilter research results helped improve the design procedure for sizing biofilters and selecting fans for the biobilters. The results are being used to design new biofilters.
Publications
- Janni, K.A., Maier, W.J., Kuehn, T.H., Yang, C.H., Bridges, B.B. and Vesley, D. 2001. Evaluation of biofiltration of air, an innovative air pollution control technology. ASHRAE Transactions, Vol 107, Part 1. pp. 198-214.
- Janni, K.A. and Allen,D.M. 2001. Thermal environmental conditions in curtain sided naturally ventilated dairy freestall barns. IN: Livestock Environment VI. Proc Sixth Int. Livestock Env. Sym. ASAE, St. Joseph, MI. pp. 367-376.
- Nicolai, R.E. and Janni, K.A. 2001. Determining pressure drop through compost-woodchip biofilter media. ASAE Paper No. 014080. ASAE, St. Joseph, MI 49085.
- Nangia, V., Janni, K.A. and Jacobson, L.D. 2001. Assessing feedlot odor impacts with OFFSET and GIS. ASAE Paper No. 014044. St. Joseph, MI 49085.
- Wood, S.L., Schmidt, D.R., Janni, K.A., Jacobson, L.D., Clanton, C.J. and Weisberg, S. 2001. Odor and air emissions from animal production systems. ASAE Paper No. 014043. ASAE, St. Joseph, MI 49085.
- Huiqing G., Jacobson, L.D., Schmidt, D.R., Nicolai, R.E. and Janni, K.A. 2001. Comparison of five models for setback distance determination. ASAE Paper No. 014045. ASAE, St. Joseph, MI 49085.
- Janni, K., Jacobson, L.D., Schmidt, D.R., Wood, S. and Koehler, R. 2001. Livestock and Poultry Odor Workshop. Dept. of Biosystems and Agricultural Engineering, Univ. of Minnesota, St. Paul, MN, 186 p.
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Progress 01/01/00 to 12/31/00
Outputs
Temperatures and relative humidity levels were measured in three representative naturally ventilated, curtain-sided, freestall dairy barns for 12 months. Data from three weeks (i.e., cold, mild, and warm) were analyzed. Inside temperatures were always kept above -18 C during the coldest week in January. Two barns had temperature differences between inside and outside that exceeded 6 C during the coldest January week for over 80% of the week. The maximum temperature difference recorded was 18 C. Relative humidity values inside the three barns exceeded 80% nearly 100% of the hours during the coldest January week. During the warmest week in July, the relative humidity levels inside exceeded 80% between 52 and 67% of the hours. Temperature-humidity index (THI) values in the three barns ranged from 64 to 83 during the warmest week in July. THI values exceeded 78, (i.e., mild stress) between 16 and 21 hours during the July week. All three barns had mixing fans and sprinkler
systems to provide cooling for the cows during warm weather. This thermal environmental data is needed to assess the performance of naturally ventilated, curtain-sided freestall barns to help builders and producers design, build, and manage these barns to economically provide an appropriate environment all year round. Biofilters are an effective technology for removing odor, hydrogen sulfide and ammonia from air from livestock facilities. Proper biofilter design is critical to provide effective and economical treatment. An improved design procedure was developed based on research and field experience. Long-term performance (pressure drop and odor reduction efficiency) monitoring of biofilters treating air from swine and dairy facilities continued. The 0.9-m deep dairy biofilter achieved odor, hydrogen sulfide and ammonia percent reductions that ranged from 57 to 100%, with many values at 90% or above. The 25-cm deep swine biofilter achieved odor and hydrogen sulfide percent reductions
that ranged from 50 to 98%. Ammonia removal ranged from 0 to 67%. Biofilter media moisture content is critical for biofilter performance. Odor and hydrogen sulfide removal efficiency decreases as the biofilters appear to dry out. Experiments were conducted to evaluate the effectiveness of different biofilter media mixtures. There were six compost:wood chip mixtures (0:100, 10:90, 20:80, 30:70, 40:60, and 50:50) and three moisture levels (30-40%, 45-55%, and 60-70%). The eighteen biofilters (24 in. x 24 in. with 12-in. deep media) were supplied with air from a swine manure pit. The airflow rates were set to provide approximately a 5-s residence time. Data collection was completed and analysis is ongoing. Preliminary results indicate that media mixtures with between 30% and 50% by weight of compost and wood chips between 70% and 50% (by weight) are equally effective reducing odor emissions. Moisture is critical to biofilter performance.
Impacts
The temperature and relative humidity data from the curtain-sided, naturally ventilated, freestall dairy barns continues to build the database that documents that ventilation management impacts the environment created in these barns. Information on thermal stress will help producer adjust rations and ventilation to improve animal health and milk production. Odor concerns are placing new restrictions on the size and location of animal facilities. This biofilter research has led to better design recommendations for livestock producers that use them for odor control.
Publications
- Nangia, V., Janni, K.A. and Martens, J.D. 2000. Thermal environmental conditions in four curtain-sided naturally ventilated freestall barns in Minnesota. ASAE Paper No. 004103. St. Joseph, MI 49085.
- Jacobson, L.D., Guo, H., Schmidt, D.R., Nicolai, R.E., Zhu, J., Janni, K.A. 2000. Development of an odor rating system to estimate setback distances from animal feedlots: Odor From Feedlots Setback Estimation Tool (OFFSET). ASAE Paper No. 004044. St. Joseph, MI 49085
- Bicudo, J.R., Jacobson, L.D., Janni, K.A., Guo, H. and Tengman, C.L. 2000. Odor and hydrogen sulfide emissions during agitation and pumping of stored dairy and swine manure in Minnesota. ASAE Paper No. 004049. St. Joseph, MI 49085.
- Kammel, D.W. and Janni, K.A. 2000. Facility design for the transition cow. IN:Dairy Housing and Equipment Systems: Managing and Planning for Profitability, NRAES-129, Ithaca, NY.pp. 340-352.
- Janni, K., Jacobson, L.D., Bicudo, J.R., Schmidt, D.R., Guo, H. and Koehler, R. 2000. Livestock and Poultry Odor Workshop I: Emissions, Measurement, Control and Regulation. 2000 Livestock Odor Workshop I, Dept. of Biosystems and Agricultural Engineering, Univ. of Minnesota, St. Paul, MN, 158 p.
- Janni, K., Jacobson, L.D., Bicudo, J.R., Schmidt, D.R. and Guo, H. 2000. Livestock and Poultry Odor Workshop II: Biofilters, Covers, OFFSET and Odor Management Plans. 2000 Livestock Odor Workshop II, Dept. of Biosystems and Agricultural Engineering, Univ. of Minnesota, St. Paul, MN, 100 p.
- Sun, Y., Clanton, C.J., Janni, K.A., and Malzer, G. 2000. Sulfur and nitrogen balances in biofilters for odorous gas emission control. Transactions of the ASAE (accepted)
- Janni, K.A., Jacobson, L.D., Bicudo, J.R. and Schmidt, D.R. 2000. Livestock and Poultry Odor Workshops. IN: Food Animal Production Systems Issues and Challenges, Proc. of 2000 NCR Extension Specialist Triennial Workshop (MWPS-TRI 1). pp. 85-90. May 10-12, 2000. Lansing, MI.
- Jacobson, L.D., Guo, H. Schmidt, D.R., Nicolai, R.E., Janni, K.A. and Zhu, J. 2000. Odor Ratings Systems: Odor from Feedlots Setback Estimation Tool (OFFSET). IN: Food Animal Production Systems Issues and Challenges, Proc. of 2000 NCR Extension Specialist Triennial Workshop (MWPS-TRI 1). pp. 91-102. May 10-12, 2000. Lansing, MI.
- Jacobson, L.D., Bicudo, J.R., Janni, K.A., Schmidt, D.R. and Tengman, C.L. 2000. Chronic odor and H2S emission rates from animal production facilities and manure storage units. AgEng 2000, Warwick, UK, July 2-7.
- Nicolai, R.E. and Janni, K.A. 2000. Designing Biofilters for Livestock Facilities. IN: Proc. 2nd Int. Conference Air Pollution from Agriculture Operations, pp. 376-383. ASAE, St. Joseph, MI 49085.
- Janni, K.A., and Nicolai, R.E. 2000. Designing Biofilters for Livestock Facilities. In Proc. of USC - TRG Conference on Biofiltration pp. 11-20. October 19-20, 2000. Los Angeles, California.
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Progress 01/01/99 to 12/31/99
Outputs
Temperatures and relative humidity levels were measured in two curtain-sided naturally ventilated freestall dairy barns to evaluate environmental conditions during summer weather. Barn A had an insulated ceiling while Barn B had a metal roof without insulation. The summer weather was warmer than historical averages but no extremely hot weather was observed. The highest hourly average outside temperature was 36 C (97 F). Environmental conditions in both barns were quite uniform based on weekly averages. Interior weekly average temperatures in Barn A were usually within 1 C of each other at both cow and near the ceiling levels. In Barn B the weekly average temperatures at cow level were within 1.5 C of each other. At ceiling level in Barn B the weekly average temperatures were within 2.5 C of each other. Hourly temperature differences between various locations in both barns were both positive and negative, which indicate that near ceiling temperatures were not
consistently warmer than cow level temperatures. The temperature differences observed during the warm weather were larger than those observed during cold weather. Weekly average temperatures near the ceiling in the Barn B were up to 2 C warmer than the corresponding temperatures in Barn A. However, weekly average cow level temperatures were within tenths of a degree of each other. Weekly average relative humidity levels inside both barns were 2 to 14% higher than the outside values. Environmental monitoring was begun in three different barns in conjunction with a nutrition study. The performance of twelve research scale biofilters with three different residence times (approximately 4, 7 and 13 s) was measured at three animal operations. Odor and hydrogen sulfide reduction improved from 56 to 94% as residence time increased from 4 to 7 s for the dairy and swine operations. Percent reduction remained above 89% as residence time increased from 7 to 13 s for the dairy and swine
operations. A 5 s residence time is recommended for designing biofilters on swine and dairy facilities to achieve 80% reduction in emissions. The biofilters on the poultry operation were installed without dust filters and dust accumulation on the fans prevented accurate airflow measurement. Biofilters on poultry facilities are recommended to have dust removal equipment. Laboratory experiments were conducted to determine nitrogen and sulfur accumulation in and emissions from biofilters with different media moisture content (30%, 40% and 50% wet basis) and retention times (5, 10 and 20 s). The media was a mixture of compost and wood chips. The media bed was 0.20 m high and 0.30 m in diameter. Percent ammonia removal ranged from 25 to 90% and hydrogen sulfide removal ranged from 47 to 94%. Removal efficiency varied with treatment. Both moisture content and retention time affected sulfur and nitrogen accumulation in the biofilter media. A literature review was conducted for the Minnesota
Generic Environmental Impact Statement on Animal Agriculture. The 1,500-page report addressed 12 topic areas affected by animal agriculture and involved more than 100 researchers. The report is available at www.mnplan.state.mn.us.
Impacts
The temperature and relative humidity data from the curtain sided naturally ventilated freestall dairy barns indicates that conditions at cow level were similar in both barns and may not impact cow comfort and performance. High humidity levels observed may lead to building deterioration and corrosion. The biofilter research has led to design recommendations used in odor workshops.
Publications
- Clanton, C. J., Schmidt, D.R., Nicolai, R.E., Goodrich, P.R., Jacobson, L.D., Janni, K.A., Weisberg, S., and Buckel, J.A. 1999. Dynamic olfactometry variability in determining odor dilutions-to-threshold. Transactions of the ASAE 42(4):1103-1112.
- Clanton, C. J., Schmidt, R.D., Jacobson, L.D., Nicolai, R.E., Goodrich, P.R., and Janni, K.A. 1999. Swine manure storage covers for odor control. Applied Engineering in Agriculture 15(5):567-572.
- Janni, K.A., Funk, T., and Holmes, B. 1999. Using All-Weather Geotextile Lanes and Pads. MidWest Plan Service, Ames, Iowa.
- Janni, K.A. 1999. Summer conditions in two freestall dairy barns in northwestern Minnesota. ASAE Paper No. 994008, St. Joseph, MI 49085.
- Janni, K.A. 1999. Lighting dairy facilities. IN: Proc. Minnesota Dairy Health Conference. University of Minnesota, St. Paul, MN. pp. 76-82.
- Nicolai, R. E., and Janni, K.A. 1999. Effect of biofilter retention time on emissions from dairy, swine, and poultry buildings. Paper No. 994149. ASAE, 2950 Niles Road, St. Joseph, MI 49085-9659 USA.
- Schmidt, D.R., Bicudo, J.R., and Janni, K.A. 1999. Determining odor emissions from manure surfaces using a wind tunnel. Paper No. 994033 ASAE, 2950 Niles Road, St. Joseph, MI 49085.
- Sun, Y., Clanton, C.J., and Janni, K.A. 1999. Nitrogen and sulfur balances in biofilters affected by media moisture content and gas retention time. Paper No. 99-4131. ASAE, St. Joseph, MI 49085.
- Jacobson, L. D., Janni, K.A., Bicudo, J.R., and Schmidt, D.R. 1999. Livestock Odors: Emissions, Measurements, Control, and Regulation. 102 pp. Odor workshop proceedings, Department of Biosystems and Agricultural Engineering, University of Minnesota.
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Progress 01/01/98 to 12/31/98
Outputs
Light is essential in greenhouses because plants require it at sufficient quality and quantity for proper growth and development. Light transmission and enhancement data in four greenhouses at different sites showed that overall transmittance efficiencies varied from 35% to 54%. Transmittance efficiency was higher under diffuse conditions than under direct sunlight, but irradiance was lower. Seasonal changes in solar altitude did not affect efficiency, but did affect seasonal exterior and interior light levels. Light enhancement was studied by measuring the effectiveness of 3M reflecting panels at increasing light levels at the plant canopy within the greenhouses. The overall percent light improvement due to the 3M Daylighting Panels was 6.3% at a Venlo double-poly house in Minnesota; -2.4% at a Venlo glass house in Canada; -3.3% at a wide-span twin-wall house #19 in Minnesota; and -8.3% at a wide-span twin-wall house #20 in Minnesota. Regression analysis confirmed
that the reflecting panels were more effective as global horizontal light levels increased. However, the panels did not increase light levels enough to cause statistical differences in plant response. Biofilters are an effective odor treatment technique for mechanically ventilated livestock buildings. Residence time is an important design factor. Four text biofilters were constructed with 8 or 4 second residence times to treat swine pit exhaust air. Odor reduction efficiency for the 8 and 4-second residence times was 91% and 87% respectively. Hydrogen sulfide reduction efficiency was 97% and 96%. Ammonia reduction efficiency was 82% and 74%. There was not significant difference between the 8 and 4-second residence time for odor, hydrogen sulfide, and ammonia removal. Curtain-sided naturally ventilated freestall barns are used widely in Minnesota. Northwestern MN has colder winter weather than other important dairy regions, which presents extra problems. Temperature and relative
humidity levels were measured in two barns over the past 14 months. Winter weather was warmer than normal for 1997-98. Weekly average temperatures indicate fairly uniform conditions. Hourly temperature differences up to 10 C were measured between inside and outside. Hourly temperature differences between different locations were both positive and negative, which indicated that relative temperature differences changed dramatically. Condensation was observed regularly on the metal roof inside the barn that did not have an insulated roof. Additional monitoring and analysis is ongoing. Odor and gas emission control strategies are needed for naturally ventilated livestock buildings. One strategy is to sprinkle a very small amount of vegetable (soybean) oil, uniformly over the entire inside floor area, daily. This was originally developed to reduce dust levels inside the buildings but since odorous compounds attach themselves to dust particles this may also reduce the odor in the
ventilation exhaust air. Preliminary results from an experiment done in a swine nursery showed a decrease in both dust and odor levels both inside the barn and in the exhaust ventilation air. Further work is planned in the upcoming year.
Impacts
(N/A)
Publications
- Lukindo, A.R., Janni, K.A. and Larson, T. 1997. Reinforcing properties of a ridge plate in a bolted flitch-plate joint for small round wood. TRANSACTIONS of the ASAE 41(1):187-192.
- Lukindo, A.R., Larson, T. and Janni, K.A. 1998. Extending the yield theory to a bolted flitch-plate connection. TRANSACTIONS of the ASAE 41(5):1483-1488.
- Nicolai, R.E. and Janni, K.A. 1998. Comparison of biofilter retention time and moisture content. ASAE Paper No. 984053, St. Joseph, MI 49085.
- Jacobson, L.D., Johnston, L.J., Hetchler, B. and Janni, K.A. 1998. Odor and gas reduction from sprinkling soybean oil in a pig nursery. ASAE Paper No. 984125, St. Joseph, MI 49085.
- Janni, K.A. 1998. Temperature and relative humidity conditions in two freestall dairy barns in northwestern Minnesota. ASAE Paper No. 984032, St. Joseph, MI 49085.
- Lukindo, A.R. 1999. Modeling performance of a bolted flitch-plate connection for small roundwood. Ph.D. Thesis. University of Minnesota, St. Paul, MN.
- Wagner, N.C. 1998. Greenhouse light transmission and enhancement. M.S. Thesis, University of Minnesota, St. Paul, MN.
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Progress 01/01/97 to 12/31/97
Outputs
Small round wood members (diameters less than 15 cm) have structural and economic merits that provide opportunities for their use in light frame construction. Structural use of small round wood is limited because of problems making simple and reliable connections. Bolted flitch-plate connections have the potential for overcoming that problem. Theoretical and experimental work was conducted. The Yield Theory was extended to the design for bolted round wood connections. Yield load was predicted within an average of 8% and deviated by no more than 15% compared to measured data. A new failure mode was introduced and appropriate Yield Theory equations derived. A ridged plate increased maximum loading capacity by 40% and initial stiffness by 70%. Bolt end restraints increase connection performance in the post-yield load regime. The greenhouse industry is growing at a rate of 12 to 25% per year in Minnesota. Greenhouse performance data is limited. Irradiation in three
commercial greenhouses was measured at plant level and compared to local global horizontal irradiation levels. Data was collected from October 1996 to March 1997. Overall transmittance efficiencies varied from 35 to 52 percent. Transmittance efficiency was higher under diffuse conditions than under direct sunlight but light levels were much lower. Light levels and plant production in greenhouses with commercial daylighting panels was monitored. Light levels on sunny days were increased by up to 47% but cloudy weather, snow or condensation on the greenhouse roof greatly reduce panel performance. Plant performance under the daylighting panels was inconsistent. Odors from animal facilities is a concern to both producers and their neighbors. A low cost biofilter was built to treat exhaust air from a continuously running minimum ventilating fan that withdrew air from the manure pit under a farrowing barn. The biofilter media was compost and kidney bean straw. Biofilter performance was
monitored for eleven months. Average odor threshold and hydrogen sulfide concentration were reduced by between 75 and 90 percent. A sprinkler system was added to add moisture during mild and warm weather.
Impacts
(N/A)
Publications
- NOLL, S.L., JANNI, K.A., HALVORSON, D.A. and CLANTON, C.J. 1997. Market turkey performance, air quality and energy consumption affected by partial slotted flooring. J. Poultry Sc. 76:271-279.
- LUKINDO, A.R., CHASTAIN, J.P. and JANNI, K.A. 1997. Review of small round wood connections. Wood Design Focus Journal. 8(1): 14-22.
- JANNI, K.A. and JACOBSON, L.D. 1997. Slot-inlet ventilation system performance as single speed fans cycle on and off. IN: Livestock Environment V. Proc, of the Fifth Int. Livestock Env. Sym. ASAE, St. Joseph, MI. Vol. 2 pp. 764-771..
- NICOLAI, R.E.and JANNI, K.A. 1997. Development of a low cost biofilter for swine production facilities. ASAE Paper No. 974040. St. Joseph, MI 49085.
- WAGNER, N.C., JANNI, K.A., ERWIN, J.E., THILL, C.M. and BLOM, T. 1997. Measured light transmissivity in three greenhouses. ASAE Paper No. 974064. St. Joseph, MI 49085.
- THILL, C.M., WAGNER, N.C., ERWIN, J.E., JANNI, K.A., BLOM, T., JASTER, P. and BOULAESKAIA, V. 1997. Using daylighting panels in commercial greenhouses to increase light levels. ASAE Paper No. 974065. St. Joseph, MI 49085.
- LUKINDO, A.R., JANNI, K.A. and LARSON, T. 1997. Reinforcing properties of a ridge plate in a bolted flitch-plate joint for small round wood. TRANSACTIONS of the ASAE (accepted).
- LUKINDO, A.R., LARSON, T. and JANNI, K.A. 1997. Extending the Yield Theory to a bolted flitch-plate connection. TRANSACTIONS of the ASAE (accepted).
- LUKINDO, A.R., LARSON, T.D. and JANNI, K.A. 1998. Structural metal plate connector for small round wood construction of agricultural buildings. 13th CIGR conference February 2-6, 1998 Morocco. (Accepted.)
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Progress 01/01/96 to 12/30/96
Outputs
A model was developed that described ventilating system performance as thermostatically controlled single speed fans cycle on and off. Results indicate that manually adjusted inlets cannot maintain acceptable performance as fans cycle on and off. Static pressures increases were large. No ideal inlet setting was found. Airborne transmission across a 1 meter distance was detected using infected pigs as the microorganism source. Bacterial and virus airborne transmission was strain dependent. These results are important when trying to clean facilities after a disease outbreak. A retrospective review of the weather during June, July and August of 1995 suggests that an extended period (2 to 3 days) of hot (air temperatures greater than 95 F) and humid (dew-point temperatures greater than 70 F) weather without relief (little night time cooling) and limited night time ventilation (periods of no wind) led to significant heat stress mortalities. The July 1995 hot and humid
period was extremely unusual in the historical record in terms of magnitude and duration. A 10 day period of cool and dry weather prior to the hot and humid weather may have also contributed to the mortalities.
Impacts
(N/A)
Publications
- KUEHN, T.H., GACEK, B., YANG, C.H., GRIMSRUD, D.T., JANNI, K.A., STREIFEL, A. J.,and PEARCE, M.
- R., 1996. Identification of Contaminants, Exposures, Effects, and Control Options for Construction/Renovation Activities, ASHRAE Transactions, 10 NOLL, S.A. and JANN, K.A. 1996. Feed and fuel use in turkey production. Gobbles,53(1):5.
- JANNI, K.A., NOLL, S. L., SEELEY, M.W. and JOHNSON, V.J. 1996. Summer 1995 heat stress and turkey loss. Gobbles, 53(5):4-7.
- JANNI, K.A. and JACOBSON, L.D. 1996. Slot-inlet ventilation system performance as single speed fans cycle on and off. IN: Livestock Environment V. Proc, of theFifth Int. Livestock Env. Sym.
- ASAE, St. Joseph, MI. (accepted).
- TORREMORELLI, M., PIJOAN, C., JANNI, K., WALKER, R., and.
- JOO, H.S. 1996. Airborne transmission of Actinobacillus pleuropneumoniae and Porcine Reproductive and Respiratory Syndrome (PRRS) virsus in nursery pigs. Am. J. Vet.Res. (submitted) LUKINDO, A.
- R., CHASTAIN, J.P. and JANNI, K.A. 1996. Review of small round wood connections. Wood Design Focus J. (submitted).
- LUKINDO, A. R., JANNI, K.A. and LARSON, T. 1996. Reinforcing properties of a ridge plate in a bolted flitch-plate joint for small round wood. TRANSACTIONS ofthe ASAE (submitted).
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Progress 01/01/95 to 12/30/95
Outputs
Environmental monitoring in two new 1,000-head pig finishing barns was completed. Monthly measurements included total, respirable and inhalable dust, ammonia, carbon dioxide, hydrogen sulfide and carbon monoxide concentrations. Gas and dust concentrations in the two barns were higher compared to data in more traditional barns. The air quality in these facilities was "poor" compared to many non-farm worker's environments. A project to evaluate partially slotted flooring for turkeys was completed. Electrical energy use was reduced using slotted flooring. Increased body weights and fuel savings observed in preliminary studies were not observed in the field study. Ventilation management strategies partially explain the differences. Seventeen fact sheets were developed on poultry production. Research to evaluate the effects of friction and end restraints on load bearing and initial stiffness properties of bolted flitch plate joints for small round wood continued. A
cooperative project to determine whether various viral and bacterial respiratory pathogens in pigs can be transmitted by air was initiated.
Impacts
(N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs
Hourly temperature and humidity (dew-point temperature) monitoring continued in two new 1,000-head pig finishing barns owned by cooperating producers. Monthly indoor air quality measurements including total and respirable dust, ammonia, carbon dioxide, hydrogen sulfide and carbon monoxide continues to be collected. The environmental and production data from the producers will be compared and used to establish baseline indoor air quality information on new facilities. A multi-disciplinary team monitored indoor temperature, relative humidity and mold spore concentrations for one year in selected homes flooded in 1993. Clean-up and drying strategies that minimize both the short and long term destructive effects of flooding were evaluated. Relative humidities decreased as drying proceeded. Structural members did not exhibit any degradation due to the flooding. Flooded homes all showed elevated mold levels. In some homes mold levels decreased as remodeling and repairs were
completed. Others continued to maintain high mold spore levels with aggressive sampling. A workshop was held and a video produced based on the results of this work. Another team completed a literature review and survey of selected architects and contractors to identify procedures developed for contaminant control during construction and renovation. A draft report was submitted to the funding agency. A model describing residential forced-air ventilation was developed. Experimental work is planned for model validat.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
Dust generation from swine feed treated with soybean oil was investigated using a cement mixer in a plywood box. Total airborne dust concentrations in the box were measured while 12-kg feed samples were mixed. Treatment variables were soybean oil concentration, (0, 1 and 3%), corn test weight (normal - 730 kg/m3 and low - 600 kg/m3), time of oil addition (before or after grinding the corn), and storage time (0, 7 and 14 d). The feed was a mixture of ground corn, soybean meal, base mix, and soybean oil. Adding soybean oil to the feed made with normal test weight corn at the 1% and 3% levels suppressed total dust generation compared to the no oil treatments (29.1 mg/m3). The 3 % oil treatment (.99 mg/m3) suppressed dust generation more than the 1% oil treatment(3.39 mg/m3). Adding soybean oil after grinding the corn suppressed dust generation more than adding the oil to the corn before grinding for every oil level. More dust was generated by feed made from the low test
weight corn than by feed made with normal test weight corn at every oil level. There was no evidence of any storage time or treatment by storage time interaction effects. Flow visualization, temperature, and velocity measurements were made in a 1/5 scale model slot-ventilated swine facility. Changing the floor heating to simulate different animal occupancies produced significantly different flow patterns. Recirculation patterns in the inlet half were mainly due to forced airflow from the inlet jet.
Impacts
(N/A)
Publications
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Progress 01/01/92 to 12/30/92
Outputs
The effects of animal occupancy and an obstruction near the inlet on the overallair flow patterns and temperature and velocity distributions in a 1/5 scale model of a growing/finishing facility were measured. Independent factors were inlet corrected Archimedes Number (Arc), floor heating arrangement and obstruction location near the inlet. Three Arc were used: 22, 75 and 113. The three floor heating arrangements simulated different animal housing situations: full floor heating, outlet half heated only, inlet half heated only. The 14.3 mm diameter aluminum rod used as the obstruction was: absent, 10 mm or 50 mm below the ceiling and 0.25 m from the inlet. Inlet air jet ceiling detachment ranged from 0.6 to 1.2 m from the inlet for Arc = 22 as the floor heating arrangement varied. Jet detachment was 0.4 m for Arc = 75 and 0.2 m for Arc = 113 and changed little as floor heating varied. The overall flow patterns were similar when the floor was fully heated and when the
outlet half was heated for all three Arc. The similar air flow patterns indicate that the recirculating patterns in the inlet half of the facility were created mainly by forced convection of the inlet jet. Airflow was unorganized in the outlet half of the chamber when the outlet half was unheated. The obstruction near the inlet had the most significant effect when the floor was fully heated, the obstruction was located 10 mm below the ceiling and Arc = 22.
Impacts
(N/A)
Publications
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Progress 01/01/91 to 12/30/91
Outputs
Total energy consumption in four commercial turkey grower barns was monitored for over a year. All four barns were managed and controlled by the owners. The purpose was to obtain baseline field data and identify potential energy savings that maintained production. Total energy included feed and fuel. Feed energy was based on the energy content on the diets fed and the amount of feed to each flock. Fuel energy included the electrical and gas used in each barn. Temperature and air quality data was collected as well as production and processing data. The temperature data indicated that the weather during the study was generally warmer than historical norms. Total energy use during the heating season increased by as much as four fold in all four barns. In three of the barns the fuel use increased between 20 to 40 times. In the remaining barn both the feed and fuel use increased significantly. Mortalities were between 0.36 annd 0.96% in all of the barns except when
a bird piling incident occurred. Air quality indicators followed expected trends. Ammonia, carbon dioxide, total dust and respirable dust concentrations increased during the heating season when ventilation was reduced. Processing plant condemnations ranged between 1.2 and 6.8% and followed typical seasonal trends. Further analysis of the data is planned. Plans for remodeling a 1/5 scale model swine unit with a heated floor, modeling animal heat production, were developed and initiated for future experiments.
Impacts
(N/A)
Publications
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Progress 01/01/90 to 12/30/90
Outputs
Three-dimensional turbulent mixed airflow was studied. An experimental 1/5 scalemodel swine unit had a heated floor to simulate animal heat production. Experimental and numerical results showed that high Archimedes Number flows formed a thermal dome near the symmetry plane of the chamber producing a three dimensional temperature distribution. The thermal dome was due to cross-stream circulation due to Benard Convection. The numerical model was based on the Lam-Bremhorst Low-Reynolds Number modified version of the fully-turbulent k-(epsilon) model. Theoretical work on compressible flows in milking vacuum systems produced a finite lump bond graph scheme for describing isothermal and isentropic compressible pipe flows. A new element was defined to model convective acceleration. A model was used to analyze milking vacuum system design. Milking vacuum systems behave as first order low-pass filters in response to disturbances. A large internal volume and/or small pump
capacity result in a slow system. Increasing pulsation frequency can reduce vacuum variation. System response speed and phase differences are mainly determined by tank and receiver jar volume. Regulators should be adjustable to be tailored to individual systems. A milking system test unit was built to identify which factors impact the occurrence and magnitude of reverse vacuum differences (RVD's). RVD's are defined as a higher vacuum at teat end than in the claw and are believed to contribute to mastitis.
Impacts
(N/A)
Publications
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Progress 01/01/89 to 12/30/89
Outputs
Temperature, pressure, wind speed and direction, and sidewall opening size were monitored around a naturally ventilated swine finishing barn. Important factors were identified. A model using conventional thermal bouyancy and wind pressure coefficient methods was evaluted. A well designed and managed naturally ventilated buildings can maintain satisfactory environmental conditions. Wind speed begins to dominate natural ventilation around 2 m/s in cold weather and 1.5 m/s in warm weather. The uniform internal pressure assumption is valid if sidewall openings are small regardless of wind speed. Temperature flucuations in a mechanically ventilated swine nursery were monitored. Temperature differences greater than 40 C were found between ceiling and floor when the heater is on. Thermostat deadband, time constant, and sensor location affect temperature flucuation. Vacuum levels, air flow rates, and temperature in a vacuum milking system were measured and modeled. Pulsation
was the main source of periodic vacuum variation. Vacuum variation from 2 to 20 kPa peak-to-peak occur in liners, claws, and pulsation lines. Air temperature variation was negligible. Mach numbers for air flow in the vacuum lines were less that 0.3. The bond graph technique was used to develop a model that matched measured vacuum level data very well.
Impacts
(N/A)
Publications
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Progress 01/01/88 to 12/30/88
Outputs
A general Monte Carlo based technique for estimating shape factors for radiant heat transfer calculations was developed. The technique can be used to determine radiation shape factors for complex geometric situations typically found in livestock housing. This information is essential for calculating radiant heat transfer to and from animals in various environments. The technique was used along with other research to define and develop a method for calculating an effective environmental temperature (EET) for newborn pigs. The EET is an index that describes the radiative and convective environment that a newborn pig is exposed to and incorporates the effects of dry bulb temperature, radiant heat transfer and air velocity. Two steady state natural ventilation models using different methods for estimating the thermal buoyancy were developed. A microcomputer based data acquisition system was calibrated and installed in a commercial naturally ventilated swine finishing
barn. Data were collected to evaluate the building's performance and to validate the two models. The building was well managed and performed very well based on the facts that the inside temperature never dropped below 6 C, the inside temperature varied less that 10 C each day, and the relative humidity was consistently less than 35%. Both models estimated inside temperatures and humidity ratios very well. Research has been begun on the dynamics of a swine nursery ventilation system.
Impacts
(N/A)
Publications
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Progress 01/01/87 to 12/30/87
Outputs
A model describing the convective and radiative heat loss from a 1.6 kg new-bornpiglet with different hover treatments was completed. Temperature, air velocity and heat loss data from a cylinder representing a piglet was collected to validate the model. The results showed that a 0.315 m/s reduction in draft velocity and a 45% reduction in the shape factor between the piglet and enclosure walls produced a 4.84 W (19.2%) reduction in heat loss compared to the no hover control. In this study heat loss was independent of hover surface emissivity. The mathematical model matched the experimental results very well. As a part of this project a technique for finding shape factors and a definition of an effective environmental temperature were developed. A model of natural ventilation including both wind induced and thermal buoyancy effects was developed. Temperature data from a commercial naturally ventiallated swine barn compared very well with the model results.
Comparing model results and measured data over a three day period resulted in a determination coefficient of 0.83 and an estimated standard error of 2.2C. Nursery age pigs were stressed by imposing fluctuating temperatures and intermittent drafts. A slight depression in humoral immune response was observed in the pigs in the fluctuating temperature treatment. No significant performance or discernable clinical health differences were found.
Impacts
(N/A)
Publications
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Progress 01/01/86 to 12/30/86
Outputs
Research on reduced ventilation rates and drafts on nursery age pigs indicated that neither affected piglet performance. No clinical health differences were observed although antibody response suppression was found in the piglets stressed by a draft. This indicated that even though the pigs appeared healthy and showed no decrease in production they were stressed and more susceptible to disease. Air quality in five commercial turkey barns was monitored to determine the effects on the incidence of aspergillosis in the turkeys, mortalities and processing plant condemnations. The results indicate that feed and litter were important sources of Aspergillus spores while airborne levels were below 1.0 CFU/cu m. Different ventilation systems had different total dust concentrations. Aerosol concentrations of particles less than 10 microns were not correspondingly higher in the barns with high total dust concentrations. A computer model describing turkey grower barn
ventilation was developed. The model was based on sensible heat and moisture balances. It includes a description of moisture movement into and out of the litter, an important ventilation management parameter. A computer model was also developed to describe the convective and radiative heat loss from a 1.6 kg piglet. The model includes a hover, which some producers use in farrowing and nursery rooms to create a warm microenvironment for the piglet.
Impacts
(N/A)
Publications
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Progress 01/01/85 to 12/30/85
Outputs
A full scale model of an eave inlet, slot inlet and attic cross-section was built to determine loss coefficients and flow rates under various pressure drop situations between the attic, room and eave. With the attic area sealed shut, the loss coefficient was linearly related to slot inlet width. With various sizes of attic opening, loss coefficients were dependent on slot inlet width and attic to eave pressure differences. Below normal minimum ventilation research on early weaned piglets showed that average daily gain, feed intake and gain to feed ratios were not statistically different between units ventilated at 14 and 56 L/min/piglet. There also was no piglet "health" advantage, as measured by pneumonic lung lesions. Ammonia and carbon dioxide concentrations were from 2 to 5 times higher in the lower ventilated units while dust levels were the same or lower. Environment was monitored in a commercial turkey grower barn for one year to determine which factors
correlated with the incidence of air sacculitus. Mortality and condemnations were over 4 times higher in the winter flock compared to the summer flock. Aspergillus levels were below ambient levels reported in the literature. Aerosol, dust and ammonia concentrations were 4, 2, and 3 times higher, respectively, in the winter than the summer. A turkey ventilation model was developed to incorporate the air quality monitoring results.
Impacts
(N/A)
Publications
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Progress 01/01/84 to 12/30/84
Outputs
The wintertime natural ventilation model developed previously under this projectwas modified to use wind load data to estimate the pressure distribution at the inlet and the ridge. The results indicate the importance of wind and the wind pressure coefficients used on natural ventilation. Modification of the summertime model will be carried out. Progress has been made on the microcomputer based data acquisition system to monitor naturally ventilated buildings. Results of monitoring dry bulb and dewpoint temperatures in a unique naturally ventilated tie-stall dairy barn with slot inlets showed that it could operate well. Management was very important. With careful adjustment of the inlets, inside temperatures could be kept above freezing even when outside temperatures reached -30C. Excessively, high temperatures were avoided inside in the summer because the cows were kept on pasture except for milking. The unique uninsulated continuous open ridge flue appeared to
help control the ventilation rate by heating or cooling the exhausting air.
Impacts
(N/A)
Publications
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Progress 01/01/83 to 12/30/83
Outputs
Two natural ventilation models developed in previous years under this project were expanded to include a mechanical energy balance equation. Models now include mass, momentum, mechanical energy, and heat energy balance equations. Data is needed to check the model results. A recycled microcomputer based data acquisition system previously used in a solar energy project was installed in a unique naturally ventilated stall dairy barn. Temperature measurements at 15 different locations in the building have been monitored for a year. Data will be used in conjunction with the models. Another microprocessor based data acquisition system is being designed and constructed to obtain all the necessary data to check the models developed. Data requirements of the models have required the development of some unique capabilities. It is being designed to measure up to 32 temperature differences with an accuracy of + 0.5. Equipment and software to measure pressure differences with
an accuracy of + 10 Pa are being developed. Sidewall opening size, wind speed, wind direction and dew point temperatures will be measured. The model was used to determine the sensor accuracies required. Development of a computer program using finite element analysis to solve the differential form of the transport phenomena equations used in the natural ventilation models was also started this year. This will provide a more detailed description of the air movement in naturally and mechanically ventilated buildings.
Impacts
(N/A)
Publications
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Progress 01/01/82 to 12/30/82
Outputs
Two mathematical descriptions of the air movement through naturally ventilated livestock buildings were developed. One models the ventilation of gable roofed buildings with an open ridge and openings in only one sidewall. The second model describes natural ventilation in gable roofed buildings with an open ridge and sidewall openings in both sidewalls. The models were developed using principles of transport phenomena. The models include both wind induced forces and bouyant forces in a single system of equations. Buoyant forces due to temperature, pressure and humidity ratio gradients were included. Building dimensions and environmental values are included as physical parameters. The models can be used to evaluate different building designs and management schemes under varying weather conditions. The model results compare well with the limited published data available, but further data is needed to thoroughly check the models. Work on the procedures for sampling
livestock environments to quantity noxious gases has also been started.
Impacts
(N/A)
Publications
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Progress 01/01/81 to 12/30/81
Outputs
The dispersion of odors from agricultural production facilities was studied using an Environmental Protection Agency air pollution model. The results indicated that wind speed and local climatic conditions have a significant effect on dispersion. Identifying conditions favorable for rapid dispersion when short-term potentially odorous jobs are being done would help reduce odor complaints. Adequate separation distance between odor sources and neighbors is considered important in farmstead planning and its importance was verified by the model. Reducing production and release of odorous compounds into the atmosphere in turn reduces the atmospheric concentration. This provides an approach for long-term control of odors under varying weather conditions. For agricultural problems, the use of stacks to increase the height that odorous compounds are released produced very little long-range reduction in atmospheric concentrations. Lack of field data prevented
quantification of the results of the model. An analysis of natural ventilation of confinement livestock buildings using transport phenomena theory was started. The mathematical description developed includes different building designs, management practices and to understand the physical processes involved in natural ventilation.
Impacts
(N/A)
Publications
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