Better Understanding Cross Vent vs. Tunnel Ventilated Dairy Facilities

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Amber Sutton
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1 Better Understanding Cross Vent vs. Tunnel Ventilated Dairy Facilities Michael J. Wolf DVM Consulting Veterinarian VES Environmental Solutions Tunnel/Cross-Vent Ventilation Goals Provide Fresh Air Continually Across Ventilation Stages Create Effective Cow-side Velocity (ECV) Direct Cow Cooling by Soaker System plus ECV Ambient Temperature Drop with Supplemental High Pressure Fog (HPF) Dynamic Control System to Optimize Operational Efficiency Why Controlled Ventilation Environments are Becoming Popular Wind Shadows from Existing Facilities Hampering Natural Ventilation Variation in Ambient Wind Direction, Intensity, Duration Wider/Longer Facilities Higher Cow Numbers Under a Given Facility Higher Milk Production/Cow Requiring more Agressive Heat Abatement Manure Management During Winter in Northern Climates Air & Heat Exchange Specifications Usually designed for CFM per Adult Cow for Heat Transfer (approximately 1500 watts generated/cow/hr) Air Exchange/Hr (ACH) Usually 4X/Hr Minimum Winter 15-20X/Hr Transition Weather X/Hr Summer 1

Tunnel Ventilated Facilities Usually Designed with Inlet at the Prevailing Summer Wind Direction Local Wind

Barns Exceed 500 ft Length Air Quality Diminishes Towards the Exhaust Fans 4-8 Row Widths Common Air Speed is

Actual ECV Over Cow in Stall Bed Below Neck Rail Tunnel Ventilated Facilities Tunnel Air Flow Pattern Baffles

Circuiting (feed lanes & scrape alleys) ECV in Stall Beds Slows Quickly After Baffle Supplemental

2 Tunnel Ventilated Facilities Usually Designed with Inlet at the Prevailing Summer Wind Direction Local Wind Roses from Weather Sites Indicate Monthly Prevailing Winds Target 5-6 mph Cross Sectional Velocity As Tunnel Barns Exceed 500 ft Length Air Quality Diminishes Towards the Exhaust Fans 4-8 Row Widths Common Air Speed is a Calculated value Based on Theoretical Cross Sectional Area Usually Xsection Below a Baffle Does Not Reflect Actual ECV Over Cow in Stall Bed Below Neck Rail Tunnel Ventilated Facilities Tunnel Air Flow Pattern Baffles Help to Increase Air Speed Based on Cross Sectional Area Generally Mounted 60 ft Apart or Less Short Circuiting (feed lanes & scrape alleys) ECV in Stall Beds Slows Quickly After Baffle Supplemental Recirculation Fans May Be Needed Air Speed and Static Pressure (Sp) Must Be Balanced Short Circuiting Consequences of Short Circuiting 2

3 Retrograde Air Flow in a High Sp Barn High Speed Tunnel Flow with Panel Fan ECV Fan as Power Baffle with HPF Hybrid Tunnel Inlet End Polycarbinate side walls Hybrid Tunnel MidSection ECV72 Application Hybrid Tunnel Exhaust 3

TEMP F 2/8/2017 0:00 2/9/2017 0:00 2/10/2017 0:00 2/11/2017 0:00 2/12/2017 0:00 2/13/2017 0:00 2/14/2017 0:00

Hybrid Tunnel Arid Climate Application Temp Ambient - Barn - Cow Zone Temp Ambient Barn Temp Cow Zone

Weather Sites Indicate Monthly Prevailing Winds Common for 1000+ Cow Facilities Usually 8-16+ Row Barns (20

5-1 /12 ) Reduces Barn Volume & Construction $/Cow Target 5-6 mph at Baffle (No Baffle Designs) Designed More

Facilities Baffles Generally Located Over H-H Stalls Trapping of Foul Air Between Baffles (esp winter)

4 TEMP F 2/8/2017 0:00 2/9/2017 0:00 2/10/2017 0:00 2/11/2017 0:00 2/12/2017 0:00 2/13/2017 0:00 2/14/2017 0:00 12:00 AM 11/2/2017 Hybrid Tunnel ECV72 with HPF & Soakers Cow Level Temp Probe Hybrid Tunnel Arid Climate Application Temp Ambient - Barn - Cow Zone Temp Ambient Barn Temp Cow Zone Cross-Vent Facilities Usually Designed with Inlet at the Prevailing Summer Wind Direction Local Wind Roses from Weather Sites Indicate Monthly Prevailing Winds Common for Cow Facilities Usually Row Barns (20 row) Low Roof Pitch (0.5-1 /12 ) Reduces Barn Volume & Construction $/Cow Target 5-6 mph at Baffle (No Baffle Designs) Designed More for Air Speed at Baffle not Total ACH Short Circuiting Through Service Lanes DATE/TIME/PERIOD Cross-Vent Facilities Baffles Generally Located Over H-H Stalls Trapping of Foul Air Between Baffles (esp winter) Retractable Baffles? Headlocks & Curbs are Baffles Also! Power Baffle Designs with Recirculation Fans Must be Mechanically Ventilated 24/7/365 Adequate Backup Generator Capacity a Must Air Speed & Static Pressure (Sp) Must be balanced 4

5 Cross-Vent Without Baffles Cross-Vent Without Baffles Cross-Vent with H-H Stalls Cross-Vent with H-H Stalls Cross-Vent with H-H Stalls 5

6 Cross-Vent with Headlock Cross-Vent with Headlock Back Scrape Alley with Headlock Cross-Vent with Cows & Headlocks Cross-Vent with 72 Blast Fan Power Baffle Cross-Vent with 72 Blast Fan Power Baffle 6

Cross-Vent with ECV72 Fan Power Baffle Future Ventilation Designs Neutral Pressure Designs for cool/cold conditions Full Neutral Pressure Designs 24/7/365 Greater

7 Cross-Vent with ECV72 Fan Power Baffle Future Ventilation Designs Neutral Pressure Designs for cool/cold conditions Full Neutral Pressure Designs 24/7/365 Greater Use of Variable Frequency Drives (VFD) Higher Efficiency Motors Inclusion of Programmable Logic Controllers (PLC) Efficiency Modes for Optimal Electrical Management 7

VENTILATION PRODUCTS. For The Dairy Industry. (519)

VENTILATION PRODUCTS. For The Dairy Industry. (519) VENTILATION PRODUCTS For The Dairy Industry (519) 527-2198 www.enviranorth.com 1 TECHNICAL SPECIFICATIONS OF SAILFIN FANS Fans range from 12 ft to 24 ft (3.7 m to 7.3 m) in diameter Capable of moving nearly