Consider a cow's perspective when designing ventilation systems for new or existing facilities.ceramic magic cube for the medical, Approach all decisions with the cow in mind putting priority on her health regarding the design, construction, equipment selection and management.
Dr. Robert Graves, professor, Penn State Department of Agricultural and Biological Engineering and Dan McFarland, Penn State Extension engineer discussed this theme during Penn State Extension Dairy Team's last webinar session, "The Aerial Environment: Fresh Air and Plenty of It." This session is part of the cow-centered housing webinar series, which evaluates dairy cattle housing from the cow's viewpoint, especially as it relates to her comfort and well-being.
No matter what barn type she lives in, a cow's needs remain the same.A long established toolmaking and trade Injection moulds company. Providing fresh air satisfies one of these needs. "Ventilation systems, properly designed and managed to maintain desirable moisture, gas and pollutant levels during all seasons, are essential to the health performance and well-being of dairy cows," explained McFarland. Air quality impacts the cow's ability to work.Your Partner in Precision Precision injection molds. Determine goals before designing a new building or remodeling an already built structure.
"Cows need to be clean, dry and comfortable," stated Graves, "We know clean and dry. She knows comfortable." Graves quipped, "She is the expert [on cow comfort]!"
Proper ventilation creates an air exchange, distributing fresh air everywhere while removing moisture. It controls heat, enhances cooling, and protects the building. Superb ventilation exists when the air quality inside the building equals the air quality outside the building.If any food Ventilation system condition is poorer than those standards, Four key components compose ventilation systems-inlets, air distribution, a moving force and outlets.
Four types of ventilation systems exist. Cold ventilation follows the temperature outside. Mechanical ventilation utilizes fans to draw air from the inlets through the outlets. Warm ventilation or tie-stall, as it is sometimes called, keeps the temperature inside the building above freezing. Natural ventilation relies on wind bringing the air across the barn.
All share a simple goal-provide good quality air at all times to all cows. Combining different systems makes this goal more easily achieved.
Mechanical ventilation relies on a slight pressure differential to operate optimally. It needs multiple fans to minimize temperature fluctuation during all seasons. "This is key," stated McFarland. It requires accurate controls and adjustable inlets properly located to provide fresh air throughout the building. In regards to fans "you get what you pay for" said McFarland, referring to the many ranges of fan quality. Remember though, circulation fans do not exchange air. They move it around or circulate it.
Close all unplanned inlets (open doors, broken winows, etc.) and locate fans six to eight feet away from inlets to eliminate air short circuiting. "Air is lazy," said McFarland, "It will follow the easiest path."
Animal heat drives natural ventilation.Do not use cleaners with porcelain tiles , steel wool or thinners. A minimum of a one mile per hour (mph) wind speed is required to create an air exchange to keep temperatures constant and remove moisture. Utilizing predominant prevailing winds makes this system efficient. These winds tend to be very site specific. When determining a buildings orientation find these winds to make this system operate optimally.
Keep in mind the terrain surrounding the building or site and if any other obstructions are around altering wind speed or direction. An upwind obstruction can change airflow five to 10 times its height. Separate a building from another building 2.5 times its height with 75 feet preferred and 50 feet being the minimum. Remember to consider any upwind buildings "wind shadow" or distance before the wind will return to cow level. A simple equation DSD (design separation distance) = 0.4 (HGHT (total upwind building height (feet) to ridge)) X (LGTH (total length (feet) of upwind building)) helps determine this distance.
Different ridge designs exist to minimize weather penetration into the barn while allowing heat to escape. Each has their own advantages and disadvantages. A ridge opening of three inches per every 10 feet of building width with 12 inches being the bare minimum is recommended.
Higher sidewalls increase air volume in the building diluting the moisture and gases in the barn. It also allows more wind exposure. The preferred sidewall height is 14 to 16 feet with 12 feet being the bare minimum. "We want to maintain around 11 square feet per cow opening," said McFarland, "Six-row barns are challenged here." Like endwalls, sidewalls should be adjustable. "During summer we want the walls to be open at cow level allowing fresh air to her while providing shade," stated McFarland, "During winter we want to block cold winds at cow level, protect her from precipitation and provide quality air."
In winter, the temperature inside the building should be about 5 to 10 degrees warmer than outside. Anything higher than this causes gas and condensation build-up compromising air quality. Winter ventilation deals with latent heat. Latent heat is evaporated water moisture in respired air excreted from animals breathing. This moisture must be removed from the building to keep air fresh, animals dry and the building protected from rot. "We must always favor air quality over manure consistency," stated McFarland.
Winter possesses perplexities because people want to close everything. During winter we tend to think in terms of "equipment operation" and "human comfort" forgetting the cow's needs said Graves.
Dr. Robert Graves, professor, Penn State Department of Agricultural and Biological Engineering and Dan McFarland, Penn State Extension engineer discussed this theme during Penn State Extension Dairy Team's last webinar session, "The Aerial Environment: Fresh Air and Plenty of It." This session is part of the cow-centered housing webinar series, which evaluates dairy cattle housing from the cow's viewpoint, especially as it relates to her comfort and well-being.
No matter what barn type she lives in, a cow's needs remain the same.A long established toolmaking and trade Injection moulds company. Providing fresh air satisfies one of these needs. "Ventilation systems, properly designed and managed to maintain desirable moisture, gas and pollutant levels during all seasons, are essential to the health performance and well-being of dairy cows," explained McFarland. Air quality impacts the cow's ability to work.Your Partner in Precision Precision injection molds. Determine goals before designing a new building or remodeling an already built structure.
"Cows need to be clean, dry and comfortable," stated Graves, "We know clean and dry. She knows comfortable." Graves quipped, "She is the expert [on cow comfort]!"
Proper ventilation creates an air exchange, distributing fresh air everywhere while removing moisture. It controls heat, enhances cooling, and protects the building. Superb ventilation exists when the air quality inside the building equals the air quality outside the building.If any food Ventilation system condition is poorer than those standards, Four key components compose ventilation systems-inlets, air distribution, a moving force and outlets.
Four types of ventilation systems exist. Cold ventilation follows the temperature outside. Mechanical ventilation utilizes fans to draw air from the inlets through the outlets. Warm ventilation or tie-stall, as it is sometimes called, keeps the temperature inside the building above freezing. Natural ventilation relies on wind bringing the air across the barn.
All share a simple goal-provide good quality air at all times to all cows. Combining different systems makes this goal more easily achieved.
Mechanical ventilation relies on a slight pressure differential to operate optimally. It needs multiple fans to minimize temperature fluctuation during all seasons. "This is key," stated McFarland. It requires accurate controls and adjustable inlets properly located to provide fresh air throughout the building. In regards to fans "you get what you pay for" said McFarland, referring to the many ranges of fan quality. Remember though, circulation fans do not exchange air. They move it around or circulate it.
Close all unplanned inlets (open doors, broken winows, etc.) and locate fans six to eight feet away from inlets to eliminate air short circuiting. "Air is lazy," said McFarland, "It will follow the easiest path."
Animal heat drives natural ventilation.Do not use cleaners with porcelain tiles , steel wool or thinners. A minimum of a one mile per hour (mph) wind speed is required to create an air exchange to keep temperatures constant and remove moisture. Utilizing predominant prevailing winds makes this system efficient. These winds tend to be very site specific. When determining a buildings orientation find these winds to make this system operate optimally.
Keep in mind the terrain surrounding the building or site and if any other obstructions are around altering wind speed or direction. An upwind obstruction can change airflow five to 10 times its height. Separate a building from another building 2.5 times its height with 75 feet preferred and 50 feet being the minimum. Remember to consider any upwind buildings "wind shadow" or distance before the wind will return to cow level. A simple equation DSD (design separation distance) = 0.4 (HGHT (total upwind building height (feet) to ridge)) X (LGTH (total length (feet) of upwind building)) helps determine this distance.
Different ridge designs exist to minimize weather penetration into the barn while allowing heat to escape. Each has their own advantages and disadvantages. A ridge opening of three inches per every 10 feet of building width with 12 inches being the bare minimum is recommended.
Higher sidewalls increase air volume in the building diluting the moisture and gases in the barn. It also allows more wind exposure. The preferred sidewall height is 14 to 16 feet with 12 feet being the bare minimum. "We want to maintain around 11 square feet per cow opening," said McFarland, "Six-row barns are challenged here." Like endwalls, sidewalls should be adjustable. "During summer we want the walls to be open at cow level allowing fresh air to her while providing shade," stated McFarland, "During winter we want to block cold winds at cow level, protect her from precipitation and provide quality air."
In winter, the temperature inside the building should be about 5 to 10 degrees warmer than outside. Anything higher than this causes gas and condensation build-up compromising air quality. Winter ventilation deals with latent heat. Latent heat is evaporated water moisture in respired air excreted from animals breathing. This moisture must be removed from the building to keep air fresh, animals dry and the building protected from rot. "We must always favor air quality over manure consistency," stated McFarland.
Winter possesses perplexities because people want to close everything. During winter we tend to think in terms of "equipment operation" and "human comfort" forgetting the cow's needs said Graves.
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