1. Per ASHRAE 1993 Fundamantals @68 Degf
2. Adapted from ASHRAE 1993 Fundamantals
Method for calculating the volume of fluid required to combine with water when the mixture is defined by weight:
V2 = V1/(1+(SG(100%-P))/P)
Where:
V1 = System Volume
V2 = Required Volume of Pure Additive
P = Percent of system that is Additive (by weight)
SG = Specific Gravity of Additive
Example:
How many gallons of Ethylene Glycol are required for a 1,000gallon system to be 30% ethylene glycol by weight? (Note: The Specific Gravity of Ethylene Glycol is 1.116)
Solution: Gallons(E.G.) = 1,000/(1+(1.1155(100%-30%)/30 %)) = 277.6
Note: Had this been Propylene Glycol, the value for Specific Gravity would have been 1.038
