Improving Ventilation in Calf and Heifer Housing Brian Holmes Extension Agricultural Engineer UW Madison Biological Systems Engineering Young Stock Facilities College & Tour Calumet County December, 2010 Defining Terms Ventilation = Exchange = Bad Out & Good In Circulation = Moving within Barn = Ventilation Draft = Types Of Ventilation Systems: Natural Ventilation Mechanical Ventilation Negative Pressure Positive Pressure Types Of Ventilation Systems: Natural Ventilation Uses forces of nature for most of ventilation Barns w/o Ceilings Open Ridge and Eaves in Winter Open Sidewalls in Summer Located to Catch Can be Supplemented w Positive Pressure Tubes and Fans or Circulating Fans Natural ventilation uses the forces of nature to cause air exchange is the primary force Natural Ventilation - Winter In Out Out 1
Natural Ventilation - Summer Out Out In Silos Obstruct Natural Ventilation In Summer Summer Corn Field Trees Hill Natural Ventilation Design Ridge Opening 2 in. / 10 ft Width Eve Opening 1 in. / 10 ft Width 12 4 Summer Openable Sidewalls Width 10 ft Minimum 2
Types Of Ventilation Systems: Mechanical Ventilation-Positive Pressure Fans Cause Exchange Fans Force Into Barn s Distribute Fresh Cold/Cool Requires Outlets Barns w Ceilings Tight Construction t Required Variations: Adjustable Slot Inlet in Holes in -Single Flow Rate Fans Blow in w/o in Warm Weather Types Of Ventilation Systems: Mechanical Ventilation-Negative Pressure Fans & Inlets Cause Exchange Fans Exhaust from Barn Barns w Ceilings Tight Construction Designed Inlets Distribute Fresh Variations: Adjustable Slot Inlet Circulating Tubes Area Inlets Positive Pressure Tubes Tunnel Choosing Type Of Ventilation Barn Has Ceiling Compliments of K. rdlund, 2007 Barn Obstructed from Ceiling Can be Removed Meet Most Nat. Vent. Criteria Tight Construction Location August 2004 investigation Feb. 2005 after tube Pens, cfu/m3 177,453 42,07 Alleys, cfu/m3 26,459 16,716 Natural Ventilation Mechanical Ventilation Positive Pressure Mechanical Ventilation Negative Pressure After supplementation, respiratory disease treatments estimated to be 25% of previous years Positive Pressure Tubes = Winter Supplement Natural Ventilation to Remedy a Design Deficiency Three or four sided pens Upwind obstructions (includes lean-too s) Eave inlets too small Ridge outlet too small or non-existent Fan Intake 3
Arrangements Narrow Barns <100 Fan Unit <30 Perforations Fan Perforated Fan <200 <30 <60 <100 W/2 Arrangements Wider Barns Top Rear Panel Open 0.7 m (30 inches) WI Ideal Calf Pen Front Panel Extended Fans Perforated Lower Rear Panel Closed 0.5 m (1 inches) Solid Side Panel <200 <60 W/2 Solid Side Panel Solid Side Panel Front Bedding Retainer Front Panel t to Scale ompliments of K. rdlund, Nesting score = 3 Legs generally not visible when lying down 4
Individual Calf Pen Designs Modular Calf Barn w/ Individual Pens (1 of 2) WI Ideal Calf Pen Modular Calf Barn w/ Group Pens (2 of 2) Mechanical Ventilation for Individual Calf Pen Barns Mechanical Ventilation for Individual Pen Calf Barns This Spreadsheet will size mechanical ventilation components for 4x floor level pen barns Brian J. Holmes It uses the concept of a positive pressure ventilation tube to introduce fresh air into the pens using UW-Madison a distribution tube/duct. The barn is presumed to be adequately ventilated with a natural ventilation system. 460 Henry Mall Design criteria based on MWPS-7 and "Practical Considerations for Ventilating Calf Barns in Winter" by Madison, WI 53706 Dr. Ken rdlund, UW-Madison, School of Veterinary Medicine. 60-262-0096 bjholmes@wisc.edu Values in yellow cells are user changeable. March 22, 2009 Room Dimensions Trajectory of Width (ft) = 52 Stream Length (ft) = 120 Heigth (ft) = 10 Pen Information Design Number of pen rows = 4 Pen Ventilation Rate (CFM) = 1,00 Number of pens per row = 30 Number of s = 2 Total Number of Pens = 120 Number Fans = 4 Pen Length (ft) = Fan Capacity (CFM/Fan) = 450 Alley Width (ft) = 10 Minimum Area (sq ft) = 0.45 Number of Rows of Holes ( 1 or 2) = 2 Minimum Diameter (Inches) = 9.1 Ventilation Rate per Pen (15 CFM/pen Minimum) = 15 Number Holes/Tube = 60 Desired Hole Discharge Velocity (600-1,200 ft/min) = 700 Individual Hole Area (sq ft) = 0.02 Hole Angle Hole Diameter (Inches) = 2.0.5 degrees Height Hole Rows Orientation 9.2 Feet Height of Bottom (ft) = 9.2 Horizontal Distance to Pen Center (ft) = 9 Length of Trajectory (ft) = 12.9 Angle of Each Trajectory(degrees) = 44.2 Hole Angle (degrees) =.5 I want to put my calves in this barn. How do I ventilate it Constant K = 5.7 Constant C = 0.7 Still Velocity (50 ft/min) = 50 Throw Distance * to Still Along Diagonal (ft) = 9.77 Horizontal Distance from to Still (ft) = 6.2 Height Above Floor to Still (ft) = 2.24 Horizontal Distance Short of Target to Still (ft) = 2.1 * Select Hole Discharge Velocity (Cell D23) so Throw Distance is less than or equal to Length of Trajectory (Cell D2) Calf Pen Alley Width Pen Length 10 Feet ft Horizontal Distance 9 Feet Spreadsheet Available: Sheboygan Co. - Calf & Heifer Mgt. Hoffman - Calf & Heifer Mgt. 5
Cumulative Ventilation Rates for Warm Dairy Barns Animal Cold * Mild Hot ** Group Calves 15 50 100 (0-2 mo.) Heifers 2-12 mo. 20 60 130 12-24 mo. 30 0 10 * 4 Changes/hr-Alternative Vent. Rate ** 60 Changes/hr -Alternative Vent. Rate MWPS-7 Adjustable Slot Adjustable Slot Mow Floor Louver Transition Winter Season Fan Fall/Spring Season Fan Mow Floor Ceiling Joist Cable Slot Inlet Positive Pressure Fans Forcing Into Through Mow Wall (Optional Two Fan System) End Wall Adjustable Baffle Side Wall Across the Ceiling Inlet Delivered Through in Barn (Located at Both Walls) 6
This Spreadsheet sizes mechanical ventilation components for calf barns Brian J. Holmes It uses the concept of a positive pressure ventilation duct to introduce fresh air UW-Madison into the barn using a distribution duct with adjustable slot inlets. 460 Henry Mall Design criteria based on MWPS-7 Dairy Freestall Housing and Equipment. Madison, WI 53706 Cells with yellow background are user changeable. 60-262-0096 bjholmes@wisc.edu February 1, 2010 Width (ft) = 30 6 Aspect Ratio Too Large Total Number of Calves = 40 Total Cross Section Area (sq ft) = 3. 12 46.0 Cross Section Area (sq ft/duct) = 3. 1 30.72 Ventilation Rate (15 CFM/calf Minimum) = 15 Number of Ends of Each with Fans = 1 30 1.43 Ventilation Rate (50 CFM/calf Spring/Fall) = 50 36 15.36 Ventilation Rate (100 CFM/calf Hot) = 100 Room Volume (cu ft) = 19,200 Hot (CFM) * = 19,200 15,360 6 2560 2560 4.0 ------------------ ---------------- Miniumum Winter Continuous Four Changes/Hr (CFM) = 1,20 Hot Weather Sixty Changes/Hr (CFM) = 19,200 Ventilation Rate Minimum Winter Continuous (CFM) = 1,20 Ventilation Rate Spring/Fall (CFM) = 3,40 Ventilation Rate Hot (CFM) = 19,200 Positive Pressure Mechanical Ventilation for Calf Barns Inputs Choices Positive Pressure Mechanical Ventilation for Calf Barns Design Room Dimensions Number of Slot Inlets = 2 Length (ft) = 0 Number of s (Maximum of Two)= 1 Rectangular s That Can Work Heigth (ft) = Height (inches) Width (inches) Ventilation Rate Options 24 23.04 Condition Operating Adjustable Ventilation Rate Minimum Winter Continuous (CFM) = 600 Ventilation Fan Number Fan Fan Outlet Number Slot Inlet Ventilation Rate Spring/Fall (CFM) = 2,000 Rate Capacity of Fans Capacity Capacity Size Slot Inlets Opening Ventilation Rate Hot (CFM) = 4,000 Condition (CFM) (CFM) (CFM/Fan Location) (CFM/Fan Step) (SQ Ft) (inches) Inlet Opening Minimum Winter (CFM) = 1,20 1,20 1 120 120 3.2 2 0.14 Consider inte Spring/Fall (CFM) = 3,40 2,560 1 2560 120 9.6 2 0.41 Spring/Fall Sixteen Changes/Hr (CFM) = 3,40 * Fans located on sidewall(s) blowing in, locate about 30 ft apart. Selected Ventilation Rate Selected Cumulative Ventilation Rate Fan Information Slot Information QUESTIONS 7