Your service quote names R410A, but the manufacturer's current chiller page shows R454B. Or an equipment list says only “chiller refrigerant,” with no model or circuit number. Neither situation gives you enough information to approve the order. A chiller's refrigerant depends on the exact equipment and its documented service history. Match the recommendation to the installed unit, not just a series name or today's brochure. If the paperwork conflicts, ask the service provider or manufacturer to resolve it before any refrigerant is added. First, separate the chilled-water loop from the refrigerant circuit In a typical vapor-compression chiller, water carries heat back from the building or process. At the evaporator, that heat passes into a separate refrigerant circuit. The compressor, condenser and expansion device move that heat onward so the water can be cooled again. Trane's explanation of how chillers work describes these two connected heat-transfer jobs. This distinction matters when a work order says “coolant.” It could refer to the water-side fluid rather than refrigerant. Ask which circuit the work concerns. A request to correct water flow or the water-side fluid condition is not, by itself, a request for a refrigerant cylinder. The same caution applies when the building is warm. That observation does not establish low refrigerant. Ask for the actual alarm, operating observations and diagnosis. Keep water-flow problems, heat-transfer problems and refrigerant-circuit work separate in the service scope. The series name can survive a refrigerant change “CGAM” is a useful example of why a short model name is insufficient. Trane's European September 2011 CGAM manual, CG-SVX19C-E4 , describes R410A equipment. The current US CGAM product page lists R454B. Those documents describe different equipment offerings. They do not establish a universal year when every CGAM changed refrigerant, and neither authorizes converting an older unit. A current webpage is useful for identifying the present product; it cannot overwrite the records of a machine already installed. Capture the complete unit model and serial number , along with the manufacturing year if documented. Have the manufacturer or service provider match the manual's region, design version and revision to that unit. If someone sends only a brochure screenshot, request the equipment-specific reference supporting the recommendation. “Air-cooled” or “water-cooled” is not a refrigerant specification These terms describe how a chiller rejects heat. They do not uniquely identify the refrigerant inside it. For example, Carrier's 30RAP technical specifications identify R410A, while its regional 30RW/RWA AquaSnap documentation identifies R407C. These are model-specific examples, not rules for all chillers with similar names. If your asset register says only “air-cooled chiller, 60 tons,” it needs more detail. Cooling capacity is not the refrigerant designation, and it is not a refrigerant weight. Use the unit identification to request the correct equipment file. Our guide to matching refrigerant to equipment provides the broader application checks if several types of cooling equipment share the site. Keep the circuit number beside the charge information The historical CGAM manual describes single- or dual-circuit equipment, with multiple compressors possible on a circuit. It also directs readers to the product nameplate for refrigerant type and quantity per circuit. Counting compressors is therefore not a reliable way to count separate charges. Ask the service provider to identify the affected circuit on the work order. Preserve the units and circuit headings when photographing or transcribing the plate. A cropped number without its heading can leave a buyer unable to tell whether it belongs to one circuit or the entire machine. The specified full charge is not an instruction to add that amount. For a service purchase, request the quantity actually required for the documented work. Do not calculate an addition by multiplying a nameplate figure by the compressor count or by assuming the circuit is empty. Resolve conflicting records before turning them into an order If an old invoice, replacement compressor label and unit record disagree, send the discrepancy to the service company. Ask for the record explaining any previous conversion or component replacement and the manufacturer's support for the present configuration. Do not pick whichever refrigerant appears on the newest loose document. A useful service recommendation should answer three questions together: Which machine and circuit? Which refrigerant is supported for its present configuration? What diagnosed work requires the stated quantity? Our questions to ask about a refrigerant service quote can help you review that last step. Refrigerant identification and circuit service belong with qualified personnel; the checks here do not require opening panels or connecting gauges. Once those answers agree, the HVAC refrigerant options can support a matched purchase. If the records are incomplete, the next task is resolving the equipment file. A short decision path for the service order What you have What to do next A request for “coolant” or a water-flow complaint Identify whether the work concerns the water side or refrigerant side. A series name and a current product-page screenshot Obtain the installed unit's full model, serial and matching manual. A charge figure with no circuit heading Request the complete plate or equipment record and circuit identification. Different refrigerants in the unit file and service history Have the manufacturer or service company reconcile the configuration. Matching equipment records and a diagnosed service need Confirm the exact designation and required service quantity before ordering.