Placing a simple shade over an animal exposed to a hot environment and direct radiant energy from the sun, cuts the radiation heat load on that animal about 45%. Addition of one wall caused an additional 5% reduction, and each additional wall (up to three) caused an additional 2% reduction—making a total reduction in radiation heat load resulting from a three-sided shelter of about 54%, according to this report of Davis tests.

This was a cooperative investigation between the Agricultural Engineering Research Division, ARS, USDA, and the U.C. Agricultural Experiment Station.