Univ. Missouri instructor presented heat stress study at Professional Dairy Producers of Wisc and Univ. AZ presentation at Western States Dairy Conference.
Louisiana researchers reported that sprinkling cows prior to entering shade reduced respiration rates by 65 to 81% and body temperatures by 46 to 59% over shade alone. They also found that using sprinkling in combination with supplemental airflow resulted in a rapid change in body temperature and respiration rate was superior to either a fan or sprinkling alone. Kansas State Univ. studies have shown that soaking the hair of cattle once every 5 minutes in association with 6 to 8 mph airflow reduced respiration rates by 50% after one and a half hours of treatment.
The six blade Macro Air Technology High Volume Low Speed ceiling fans are superior to tunnel ventilation evaluated by Penn State University for heat stress relief. Tunnel air circulation design requires structure with closed side walls of limited height and width. Even in shade, mechanical ventilation is required when temperature is over 75 degrees and 20% humidity. Properly designed tunnel ventilation can provide high air exchange average of 1250 CFM at 400 FPM to increase milk production yet is not suitable year around for fresh air distribution. Univ. Vermont Ext. states fan use for fresh air will enhance animal respiratory health, and integrity of buildings due condensation control.
Study released by Iowa State Univ. Ext developed by Univ. Florida Animal Science reports fans support facility to increase loss heat stress from conduction, convection, evaporation and radiation. That Temperature Humidity Index recommend cooling be initiated at THI of 68, or about 83 degrees F dry bulb ambient temperature or below 101.3 degrees rectal temperature even in dry cows.
Low Profile cross ventilation buildings cost less to construct and improve air exchange rates. MacroAir preferred usage will avoid cross ventilation feed barn need to control static pressure demand of axis fans, inlets and design and placement of baffles thru multiple seasons that require impact, velocity plus buffer adjustment via labor intensive manual, pressure sensors or floating flaps noted by Univ. Vermont Ext. Lack of adjustment will reduce axis fan performance and lifespan.
The low profile feed barns have no natural light and usage MacroAir fans over centerline feed drive does not interfere with proper 15 to 25 foot candle illumination. Our big ceiling fans also operate at 58 dBA noise level, far lower than 65 recorded by axial fans which are even closer to herd.
Ventilation study by Univ. NE-Lincoln Ext. shows improved animal fertility when heat stress is reduced. Plus feed intake is 8-12% less and reduces risk of acidosis where milk fat is reduced. Unobstructed ceiling fans support Univ. Missouri-Columbia evaporative cooling provided thru cycling sprinkler or fogger plus reduce duration of time water functions to maintain udder cleanliness and reduce moldy feed. This cooling also supports efforts to select appropriate feed fiber nutrients and fats, minerals and feeding frequency.
The alternate axial wall mount belt drive fans would have required more than 4 times the units according to WSU Ext. study. In addition Penn State indicates axial fans generate more disruptive noise, performance affected by lack of cleaning and run the risk of overload fan shut down failure leading to fires. Axial fans must take dead air obstructions into consideration including screening that blocks 30-50% airflow and controlled inlets. University of Minn. Extension reports efficiency of Axial belt drive fans run approx. 20% lower than BESS studies from University of Illinois due to maintenance issues of fans, guards, chimneys, shutters, inlets common in environment. Belt drive designs are not recommended in corrosive spaces, such as feed barns supported by evaporative swamp cooling which is reason warranty is only 25% that of MacroAir. While high volumes of cooling water can be reduced making dairy improved steward of the land.
Kansas State Univ. also reports that the deep column of circulating air moving across floor should aid in dilution of H2S, NH3 and NO2 seasonal emissions. This will support compliance with government CERCLA and EPCRA standards.
MacroAir HVLS ceiling fans mounted under the centerline of 105' wide x 400' dairy cow feed barn required just six 20' diameter fans in central Wash. application. Three spaces identical to this. Product initial CFM/Watts study by University of CA - Davis for Edison Electric So. Calif utility. For this application Wash. State Univ. Extension with support from Cascade Energy prepared energy conservation study for Pacific Power & Light utility.
Dairy owner advises electrical inspector reports that change of model on only two lights within 800' length barn provided sufficient power to support 12 fans. With variable three speed setting micro drive we see both quantity and quality of milk production in both cooling and heat season. This provides approx. 90% reduction in energy conservation vs alternate axial fan introduced in Dairy Farmers of America facility guidebook. In conjunction with shades the larger feed barn structures will reduce the heat stress to allow for animal to lie down for normal resting behavior. Plus adequate ventilation will maintain improved feed and cool water consumption continuity while diluting airborne contaminants and agitating birds & insects to help prevent disease. Utah State Univ. confirms this will increase both volume and quality of milk plus reduce stress to animal. With reduced animal stress and improved health the employees of dairy find animals easier to manage and can focus on regular milking.
Expect Dairy Federation and Dairy Products Commission with the funding of NRCS will find other applications for energy conservation and animal health benefits.
Also represent Schwankgroup.com infrared heaters. Persuaded Home Depot & USACE to use high intensity as higher and more uniform radiant delivery, retention of 20% free convection heat in background, 17% less cost to install, more zone control. Primo model is 67% efficient vs AGA standard 35% due to unique dual wall reflector.
1.6.2015