Compressed Air Quality Calculator

ISO 8573-1 is the international standard that grades compressed air purity along three independent axes — particulate size/concentration, moisture (as pressure dew point), and residual oil content — each on its own numeric scale. Rather than deriving those classes from first principles, this calculator uses a lookup table of typical industry-recommended classes for six common application types, from general plant air (loosest requirements) through pharmaceutical and electronics work (tightest, essentially oil-free and bone-dry). Selecting an application pulls the matching particle, water, and oil class, then two further lookups translate the water class into a required pressure dew point in °F and the oil class into a maximum allowable oil concentration in mg/m³. From the dew point requirement, the calculator recommends dryer technology: dew points at or above 45°F may only need basic coalescing filtration, 35-44°F calls for a refrigerated dryer, and anything colder needs a desiccant or heated desiccant dryer capable of reaching sub-freezing dew points.

It also estimates how many filtration stages your particle class demands. The condensate estimate is a separate physics-based approximation — it computes how much moisture your intake air actually carries at the given temperature and humidity (using an exponential approximation of saturation humidity) and converts that to gallons of condensate per day requiring drainage and treatment. Because the class assignments come from generic industry guidance rather than your facility's own compliance requirements, always cross-check the recommended classes against your process's actual specification or client contract before finalizing equipment.