| Oil-Free Air Quality | Whether the compressor produces air without intentional oil added to the compression chamber and whether the complete system maintains the required air purity. | ISO 8573-1 Oil concentration should be verified against the required purity class, especially for Class 0 applications. | Independent test report, certification scope, sampling method, operating conditions, and a clearly stated oil-concentration limit. | Food, pharmaceutical, electronics, medical, and textile processes can be damaged or contaminated by oil aerosols or vapors. | 20% |
| Rated Flow and Pressure | Actual delivered air capacity at the buyer’s required discharge pressure, rather than nominal motor size or free-air displacement alone. | ISO 1217 Compare declared FAD, inlet conditions, discharge pressure, and tolerance using the same test basis. | Performance test curve, guaranteed FAD, pressure range, turndown data, and test conditions. | Incorrect comparison can cause undersizing, unstable plant pressure, or unnecessary energy consumption. | 15% |
| Energy Efficiency | Specific power across the expected load profile, including full-load, part-load, unloaded, standby, cooling, and auxiliary consumption. | Specific power is normally expressed as kW per m³/min or kW per 100 cfm. Evaluate against the complete operating profile rather than peak efficiency only. | Measured specific-power data, part-load curves, control logic, motor efficiency class, and annual energy model. | Electricity is commonly the largest operating cost over the compressor’s service life. | 20% |
| Compressor Technology Fit | Suitability of oil-free scroll, oil-free screw, centrifugal, or reciprocating technology for the required flow, pressure, duty cycle, and air-quality risk. | Scroll systems are commonly suited to smaller modular flows; screw systems to variable industrial demand; centrifugal systems to high, relatively stable flow; reciprocating systems to specialized pressure duties. | Technology selection rationale, operating envelope, minimum stable flow, maximum starts per hour, and application references without relying only on marketing claims. | Technology mismatch can reduce efficiency, increase maintenance, or create unstable operation. | 10% |
| Reliability and Duty Cycle | Continuous-duty suitability, operating hours, redundancy options, allowable ambient temperature, altitude, and cooling requirements. | Review design duty, rated service conditions, restart limitations, vibration limits, and expected availability. Do not treat a warranty period as a reliability rating. | Reliability data, failure-rate information where available, maintenance history, operating envelope, and reference installations with comparable duty. | Production interruptions can cost considerably more than the initial equipment price. | 10% |
| Lifecycle Cost | Purchase price plus installation, electricity, consumables, planned maintenance, unplanned repairs, replacement parts, and end-of-life costs. | Use a multi-year total-cost-of-ownership model. Include dryers, filters, drains, cooling systems, controls, and air leaks where applicable. | Itemized quotation, five- to ten-year operating-cost estimate, recommended spare-parts schedule, and clearly identified exclusions. | A lower purchase price may result in a higher total cost if energy use or service costs are not controlled. | 15% |
| Maintenance Requirements | Service intervals, replacement components, access to wear parts, cleaning requirements, lubrication of auxiliary components, and technician skill requirements. | Compare planned maintenance by operating hours and calendar time. Identify whether specialist tools or factory-trained technicians are required. | Maintenance schedule, service manuals, parts list, consumables list, labor-hour estimate, and preventive-maintenance checklist. | Predictable maintenance supports uptime and makes budgets easier to control. | 8% |
| Controls and Connectivity | Pressure control, sequencing of multiple compressors, remote monitoring, alarms, data logging, and compatibility with plant-management systems. | Check available communication protocols, cybersecurity controls, sensor accuracy, alarm history, and compatibility with the buyer’s control architecture. | Control-system specification, communication protocol list, sample dashboards, data-retention policy, and integration requirements. | Better visibility helps reduce leaks, detect performance degradation, and coordinate variable demand. | 5% |
| Noise and Installation Footprint | Sound-pressure level, heat rejection, ventilation needs, dimensions, service clearances, foundation requirements, and indoor or outdoor suitability. | Sound data should state the measurement method, distance, environment, and operating condition. Verify dimensions with all service access panels considered. | Acoustic data sheet, layout drawing, ventilation calculation, lifting points, connection sizes, and installation requirements. | Noise, heat, and limited space can affect worker comfort, compliance, and installation cost. | 4% |
| Global Service Coverage | Local technical support, spare-parts availability, response time, commissioning resources, training, and warranty administration in the target market. | Evaluate service coverage by country or region, not merely the existence of an international sales office. | Local service contacts, response-time commitment, parts lead times, technician qualifications, warranty terms, and escalation process. | Regional support reduces downtime and import-related delays for international buyers. | 8% |
| Regulatory and Documentation Compliance | Conformity with applicable electrical, pressure-equipment, safety, environmental, and import requirements in the destination country. | Typical documentation may include declarations of conformity, pressure-vessel records, electrical test reports, material certificates, manuals, and risk assessments. | Complete technical file, certificates applicable to the destination market, multilingual manuals, and documented change-control process. | Missing documentation can delay customs clearance, installation approval, or customer qualification. | 5% |