Dairy Farm Energy Management Handbook - Wisconsin Department ...

Lighting professionals in the field report that red is not clearly
distinguishable from brown under low CRI high-pressure sodium lights.
This means that bloody discharges may not be recognizable under highpressure
sodium lights.
Mercury vapor lights give off a bluish light and have been commonly
used as yard lights; however, they are not recommended for dairy
facilities because of low efficiency, and the CRI values range from 15 to
50%. The bottom line is that you have other and more efficient options
than mercury vapor lights.
• Compact fluorescents: Compact fluorescent lights (CFL) can be used
to replace incandescent lights when the existing fixture meets the
National Electric Code safety requirements for livestock buildings. CFLs
are not very tolerant of high moisture conditions and should be housed
in a water resistant enclosure if used in a farm building. T8 Linear
fluorescent lights provide the best life cycle cost option for new
construction because of higher efficiency and longer bulb life.
In the Recommended Illumination chart, you’ll find a more detailed
breakdown of suggested lighting levels for various areas in a dairy
facility.
• Keep Lights Clean: It usually doesn’t take too long before the normal
airborne dust and dirt in dairy facilities begin clinging to lamp fixtures
and robbing the original intensity of your lighting.
Like a magnet, electrostatic forces within a
light fixture are also at work in attracting
those dirt particles and causing significant
dirt build-up over time.
There’s a fancy term for this dirt build-up on
lights, and some researchers are beginning
to look at ways to put a number on it for
dairy facilities. It’s called Luminaire Dirt Depreciation (LDD). The impact
of flies on lights is also being examined.
While some light manufacturers have data on LDDs for residential,
commercial, and industrial settings, no similar information exists for
dairy facilities. Presently, designers must use data from these
applications and try to match it as best as possible with the environment
in dairy barns.
Researchers at Cornell University and DL Tech, of New York, are doing
field studies at dairy facilities to calculate the specific impact of dust, dirt
and flies on light illumination.