Vapour-pressure deficit temperature, the relative humidity and, if possible, the canopy air temperature. We must then compute the saturation pressure. Saturation pressure can be looked up in a psychrometric chart or derived from the Arrhenius equation, a way to compute it directly from temperature is where: To convert between Rankine and degrees Fahrenheit: formula_10 We compute this pressure for both the ambient and canopy temperatures. We then can compute the actual partial pressure of the water vapour in the air by multiplying by the relative humidity [%]: and finally VPD using formula_12 or formula_13 when the canopy temperature is known. Vapour-pressure deficit
Nonresidential water use in the U.S. was 15,900 mgd. The amount purchased from public systems was reported to be 4,750 mgd in 1995 (or about 40 percent of total CII use). Based on the total floor space of 11,100 million square feet in manufacturing buildings in the U.S. and assuming average use of 215 g/ksf/d, the total use of publicly-supplied water by the CII manufacturing category in the U.S. would be about 2,400 mgd or about 20 percent of the total CII use. Nonresidential water use in the U.S. Nonresidential water use refers to all uses (and users) of publicly-supplied (municipal) water other than residential use.