| Cooling Temperature Range | 15% | The unit should state a measurable operating range, such as approximately 3–15°C, with the minimum temperature clearly defined at a specified ambient temperature and water volume. | A low displayed setpoint does not prove that the water can reach or maintain that temperature under real operating conditions. | Performance test report showing ambient temperature, water volume, starting temperature, final temperature, test duration, and measurement method. | High |
| Cooling Capacity | 12% | Cooling capacity should be reported in watts or BTU/h under defined conditions. The specification should identify whether the rating applies to a complete unit or only to the compressor. | Cooling capacity determines pull-down speed and temperature stability. Capacity figures without test conditions are difficult to compare. | Factory test data, rated cooling-capacity curve, compressor specification, and test conditions for water temperature and ambient temperature. | High |
| Pull-Down Time | 10% | Require a documented time-to-temperature result for a defined water volume, for example, the time required to cool a stated volume from 20°C to 10°C. | End users experience cooling speed rather than theoretical compressor capacity. | Repeatable test video or report with calibrated temperature readings and the same water volume used for each comparison. | High |
| Temperature Control Accuracy | 8% | The controller should specify temperature display resolution and control tolerance. A practical target is stable control within approximately ±1°C, subject to system design. | Stable water temperature improves user safety, comfort, and repeatability of cold-water sessions. | Controller specifications, sensor calibration procedure, alarm settings, and a stability test conducted over several hours. | High |
| Filtration and Water Circulation | 10% | The system should provide continuous or scheduled circulation, a replaceable filter, clearly stated flow rate, and an accessible filter-maintenance procedure. | Effective circulation helps distribute temperature evenly and supports water-quality management. | Pump flow-rate data, filter specification, plumbing diagram, filter replacement instructions, and leak-test records. | High |
| Sanitation Compatibility | 7% | The manufacturer should state whether the unit is compatible with the customer’s planned sanitation method, such as ozone or approved water-treatment chemicals. | Some chemicals and treatment methods can damage seals, metals, tubing, or sensors if compatibility is not confirmed. | Material-compatibility statement, chemical-use limits, maintenance instructions, and recommended water-treatment concentrations. | High |
| Electrical Safety | 12% | The unit should be supplied for the destination voltage and frequency, with correct grounding, over-current protection, residual-current protection requirements, and a clearly identified power rating. | Cold-plunge equipment combines water and electricity, so installation and electrical protection are critical risk controls. | Electrical schematic, rated input data, insulation and leakage-current test records, grounding test, and destination-market compliance documents. | High |
| Refrigerant and Environmental Compliance | 7% | The refrigerant type and charge must be disclosed. If a flammable refrigerant is used, the design, labeling, ventilation, service procedure, and installation requirements must address the applicable safety rules. | Refrigerant selection affects service safety, regulatory compliance, operating efficiency, and shipment requirements. | Refrigerant declaration, safety data sheet, charge quantity, nameplate photograph, transport classification, and applicable conformity documents. | High |
| Ingress Protection and Outdoor Use | 6% | The manufacturer should specify whether the enclosure is suitable for indoor, sheltered outdoor, or exposed outdoor use. Any stated IP rating must apply to the complete installed enclosure. | Water splash, condensation, rain, and improper placement can cause electrical or corrosion failures. | IP-test report where applicable, installation manual, drainage design, condensation-control details, and outdoor-use limitations. | High |
| Materials and Corrosion Resistance | 5% | All wetted materials should be identified, including tubing, heat-exchanger surfaces, seals, fittings, and filter housing. Materials must be suitable for treated water and the intended environment. | Material incompatibility can result in corrosion, leaks, discoloration, or contamination. | Bill of materials, material declarations, corrosion-resistance information, seal specifications, and sample inspection. | Medium |
| Noise and Vibration | 4% | Noise should be measured at a defined distance and operating condition. Ask for a stated decibel value rather than an unqualified claim such as “silent.” | Noise and vibration directly affect residential, hospitality, and fitness-facility usability. | Noise-test method, measurement distance, operating mode, vibration-control design, and a sample unit demonstration. | Medium |
| Reliability and Factory Testing | 6% | The production process should include leak testing, electrical safety testing, functional testing, temperature testing, and serial-number traceability for each finished unit. | Documented quality control reduces the risk of field failures and inconsistent production batches. | Quality-control plan, inspection checklist, calibration certificates, failure-rate records, corrective-action procedure, and factory audit results. | High |
| Customization and Engineering Capability | 3% | The supplier should be able to document control-panel, voltage, plumbing, enclosure, packaging, and private-label changes without compromising safety or serviceability. | Customization affects certification, tooling, spare parts, production consistency, and total project cost. | Engineering drawings, change-control process, prototype approval procedure, tooling quotation, and sample revision history. | Medium |
| Minimum Order Quantity and Lead Time | 3% | Obtain written quantities and timelines for samples, pilot orders, standard production, customized production, and replacement parts. | Lead time and order constraints affect inventory planning, cash flow, and market-launch schedules. | Formal quotation, production schedule, capacity statement, packaging specification, and written assumptions for component availability. | Medium |
| Warranty and After-Sales Support | 5% | The warranty should define coverage period, compressor coverage, excluded parts, response time, spare-parts availability, and responsibility for labor and shipping. | Cooling units require ongoing maintenance, and unclear warranty terms can create significant ownership costs. | Warranty document, spare-parts list, troubleshooting guide, service-contact process, replacement-part pricing, and escalation procedure. | High |
| Total Evaluation Score | 100% | Score each dimension from 0 to 5, multiply by the stated weight, and compare suppliers using the same evidence requirements and operating conditions. | A weighted, evidence-based method is more reliable than comparing catalog price or advertised minimum temperature alone. | Use verified documents, sample testing, factory-audit findings, and signed commercial terms before approving a production supplier. | Required |