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Electric Power Saving Fan Options For Cow Cooling
Thomas A. Shultz and Paul Williams
Summer heat stress lowers dairy cow feed intake and productive performance. Unless measures are taken to improve cow
comfort this stress can also lead to animal health problems. Various cooling methods have been used successfully to
alleviate this problem (Shultz 1986 and Armstrong 1993). These methods focus on increasing feed intake, while cooling
the cow and the immediate environment around her. Commonly fans are used together with water misting or drenching
of cows in the milking barn cow wash/holding pens and in the rest and feeding facilities. A popular practice is to use a
low volume high speed (LVHS) fan, having a 36 inch diameter with 825 rpm, for this purpose. This type of fan is effective
when placed in rows for directional air movement. The LVHS fans are usually placed a few feet above the cows and have
a safety cage.
The relatively high rpm and safety cage of the LVHS fan results in a large electrical power demand. This adds to milk
production costs that could eventually be passed onto the consumer. Fan options exist that could move an equal amount
of air with less power. One example is the ceiling fan used in homes and warehouses that cost effectively reduces heat
load. However, little comparative information exists as to how effective they would be in helping the cow overcome
summer heat stress in an acceptably economic manner. The objective of this report was to show comparisons of ceiling
fans to the traditional LVHS fan during the summer on commercial dairies. This research was requested and supported
by Southern California Edison utility company and the California Energy Commission to help reduce summer peak energy
load and potential electrical shortage to the general public.
Three experiments were made over two summers on Tulare County dairies in the southern region of the San Joaquin
Valley, in central California. These farms were typical of the area and averaged 2,000 corraled Holstein cows ea