FANS Makes Measuring Air Movement a
Ventilation fans are critical in animal barns for delivering fresh air and
removing heat, moisture, and dust. But measuring a fan's performance in a barn
has been difficult.
"Traditional techniques have been cumbersome, inaccurate by 8 to 10
percent, and slowtaking 30 to 45 minutes," says animal physiologist
J. David May, who is with the Agricultural
May, agricultural engineer John D. Simmons, and animal scientist Berry D.
Lott at the ARS Poultry Research Unit in Mississippi State, Mississippi,
overcame these problems. They designed and built FANS, short for fan assessment
FANS quickly and accurately measures air output of large, in-place
ventilation fans. The system consists of a portable anemometeran
instrument developed to measure windspeedplus a computer and software to
record and analyze measurements.
"FANS helps solve the thorny technical problem of measuring the output
of in-place ventilation fans in animal barns," says May. "Such
measurements had been theoretically possible but not technically feasible until
now. The anemometer can measure volumetric flow rates with 99-percent accuracy
in less than 4 minutes."
The anemometer has been used in ARS studies on fan components including
shutters, exhaust cones, belt guards, and propellers. Future studies will test
fan output on light baffles, fan belt condition, dust, and static pressure.
The scientists assembled and calibrated the anemometer in cooperation with
Thomas E. Hannigan, who is at the Aerospace Engineering Department at
Mississippi State University. A major fan manufacturer, Hired Hand
Manufacturing Co., of Bremen, Alabama, validated FANS at its flow laboratory.
While primarily a research tool, FANS has many useful applications. For
example, it saved a major egg company more than $200,000. To protect employees
from possible hand injuries, the company installed belt guards on 1,100 fans in
115 poultry houses.
FANS showed that ventilation remained adequate with the guards installed, so
the company didn't have to buy additional fans.
FANS can also pinpoint the best location for ventilation fans. It showed
that fans placed at the end of a long poultry house are more efficient than
those along the side walls at the end.By
Hank Becker, Agricultural
Research Service Information Staff.
J. David May heads the
Research Unit, P.O. Box 5367, Mississippi State, MS 39762; phone (601)
323-2230, fax (601) 323-3535.
"FANS Makes Measuring Air Movement a Breeze" was published
in the July 1999 issue of
Agricultural Research magazine.