Calculate Air Consumption

Medical Air Compressors Consumption Calculation p1.1

The demand on healthcare facility medical air compressors has been increased by the number of ventilators put in service. Here we look at an easy way to measure the current demand on the compressors by measuring consumption.

Calculating Air Consumption in SCFM:

This is done during the off cycle of the compressor and you record the pressure of when the system went off say (105 psig) on at (85 psig) and the (time sec) it took to go from 105 to 85. This will provide the consumption at the time of the recorded data. Consumption can vary in the system based on the demands throughout the day for OR’s and patient capacity and the use of ventilators.

Consumption (SCFM) = (.55 x G x  ΔP) /  t (sec)

SCFM = Standard Cubic Ft / Second

G = Gallon Size of Receiver (typically 120,200,240)

ΔP = PSIG Off to PSIG On (typically 20 psig most systems)

t (sec) = time it takes for the pressure to drop from it’s fully pumped up pressure (compressor cut out) to the when the compressors starts again ( compressor cut in)

Example:

SCFM = (.55 x 200 x 20)  / 60

SCFM = 36.6