CAGI's Performance Verification Program is a third-party testing program that validates manufacturers' claims of rotary compressor and refrigerated dryer performance. The program provides you with reliable and verified performance data for rotary air compressors (5-200HP) and refrigerated air dryers (50-1000 scfm).
The most expensive component in the total cost of compressed air is energy. Over the life span of a typical compressor or dryer, energy typically costs several times more than the purchase price of the compressor.
The members of the Compressed Air & Gas Institute (CAGI) have long been involved in standards for the compressed air systems industry. CAGI has worked closely with the European Committee of Compressors, Vacuum Pumps, and Pneumatic Tools (Pneurop), the International Organization for Standardization (ISO), and other standards development bodies to develop appropriate standards for compressed air and gas systems equipment.
For displacement type compressors, including rotary screw compressors, ISO 1217, Displacement Compressors – Acceptance Tests is the recognized performance standard, but it is too complex for performance testing in volume production. CAGI and Pneurop developed Simplified Test Codes which have been incorporated as appendices to ISO 1217. CAGI members agreed that published performance of their products would be based on the Simplified Test Codes and data sheets were developed to provide a standardized method of presenting the performance data. The compressor data sheets allow a common basis for comparison of some relevant items. There have been minor modifications to align appropriate sheets with the DOE procedures for some rotary compressors. In addition to reporting Package Specific Power, the data sheets have been revised to include Isentropic Efficiency for some types of rotary compressors. To learn more about isentropic efficiency, see our explanatory video.
For compressors, a useful tool to calculate energy consumption is the power cost formula. Power cost equals the brake horsepower that the compressor is using, times the conversion factor of 0.746, times the hours of operation, times the local cost of electricity per kilowatt hour. The result is all divided by the motor efficiency rating. Here's an example:
The yearly electrical cost of operating a 100 hp compressor that uses 109 brake horsepower consistently over 8000 hours, with a local electrical cost of 6 cents per kilowatt hour and a 93% efficient motor is $41,968.
The information necessary to insert into the power cost formula can be found on the data sheets, which are sources of basic information about compressor performance. This information will help you make comparisons and select the compressor that best meets your needs.
Data sheets were developed as a standard format for manufacturers to report performance so users can compare performance to aid in the selection of compressed air equipment. The data sheets are available on participants’ websites.
The following Sections have developed data sheets:
Who can participate?
Participation is voluntary and is open to all manufacturers of rotary compressors from 5-200 HP, and standalone refrigerated compressed air dryers from 50-1000 SCFM, whether they are a CAGI member or not.
How is a Participating Manufacturer recognized for participation?
Participating manufacturers and the results of the verification tests are posted on this website. Participating manufacturers that pass the verification program test procedures are allowed to utilize the CAGI Program Verification Seal on the specification sheets of their models and on their product literature. This is the Participant's public representation that the stated air flow capacities and efficiencies have been verified by an independent laboratory.
What is being verified?
The Program verifies the information that participating manufacturers publish on the standard CAGI Data Sheets, which are published on the Participants' websites and in their product literature. The data sheets define operational and performance information used during the specification and application decision making process.
How does the Independent Verification process work?
On a regular and random basis the administrator selects and tests samples of the equipment to verify that they meet the manufacturers' certified published performance ratings. Two units will be tested annually per participant. The units will be selected at random by the program administrator from manufacturer or distributor available stock. If a tested unit does not pass, the manufacturer has the option to have a second unit tested, which was previously chosen by the administrator. If this unit also fails, the manufacturer must re-rate the unit based on the test results within 30 days or be ejected from the Verification program.
What test methods are being used?
Similar to the “miles per gallon” fuel economy rating sticker on the window of a new car in the showroom, the “power per flow” energy consumption rating of an air compressor is an important piece of information when comparing compressors.
The members of the Air Drying & Filtration, Blower & Vacuum, Centrifugal Compressor, and Rotary Positive Compressor Sections have developed standard formats for reporting performance, referred to as data sheets, as a service to end users of compressed air system equipment. The industry has been utilizing CAGI’s standardized data sheets for communicating the efficiency and performance of air compressors.
The power per flow consumption metric of an air compressor has historically been stated as its “Specific Power” which is the ratio of the input electrical energy required to deliver an output flow of 100 cfm at a given discharge air pressure. In an effort to eliminate the confusion created when trying to compare the specific power, which is an energy consumption metric between two similar-sized compressors with slightly different rated discharge pressures, CAGI has introduced an efficiency rating value on its Rotary Compressor Data Sheets - Isentropic Efficiency.
Isentropic efficiency incorporates operating pressure and greatly simplifies the process of comparing the efficiencies among several like-sized compressors each having slightly different full load operating pressures. As state and federal governments mandate rules for air compressor efficiency standards, isentropic efficiency will be the metric for these standards. To ensure a better understanding of isentropic efficiency, click to watch the video on isentropic efficiency.
Data Sheet Samples
All participating members of the Air Drying & Filtration and Rotary Positive Compressor Sections have agreed to use the CAGI Data Sheets and post them on their websites.