Shah (1981)
checked the predictive accuracy of mass-transfer algorithms formulated by Carrier (1918), by Meyer (1915), and by the classical analogy between heat and mass transfer. He recommends the Carrier equation at low velocities and the analogy
at higher velocities. However, for plate-to-ambient temperature gradients less than 27°F (15°C) Shah could not substantiate the accuracy of the analogy. A study was therefore conducted to correlate mass transfer occurring at low velocities
and at low-temperature gradients, which occur more often than not on a low-slope roof.