Build a refrigerant evidence file before estimating leakage

Build the refrigerant evidence file before selecting a leakage estimate. Identify the equipment, refrigerant type and relevant service movements, then reconcile what was purchased, added, recovered or transferred. A purchase invoice alone does not establish how much refrigerant entered the atmosphere during the reporting period.

This guide helps Singapore facilities teams prepare an organisational GHG inventory. It is not instruction for handling refrigerants, repairing equipment or meeting a particular environmental permit. GHG Protocol's refrigeration tool describes several estimation approaches, including sales-based, life-cycle-stage and screening methods. The appropriate method depends on the organisation and evidence available. GHG Protocol refrigeration and air conditioning tool

Begin with the equipment and reporting boundary. Keep refrigerant identities and quantities explicit. Separate servicing evidence from stock movements. Use competent technical support for method selection, and do not turn an unexplained difference into a precise emissions claim.

Identify the units operated within the chosen organisational boundary, including relevant leased or managed arrangements. Record who owns the equipment, who operates it and who holds service records. The Corporate Standard's consolidation approach governs inventory inclusion; a contractor performing maintenance does not automatically determine who reports the emissions. GHG Protocol Corporate Standard

For each relevant unit, capture its identifier, location, refrigerant type and information needed by the selected method. Record missing or conflicting labels for clarification. Do not guess a refrigerant blend from the building age or use an emission factor merely because its name resembles the invoice description.

Link each service record to equipment, date, refrigerant and quantity. Distinguish additions, recovery, transfer, installation and disposal. Confirm the units used and whether an invoice describes a container purchased, a quantity charged to equipment or a service fee without a measured quantity.

Ask contractors to explain ambiguous descriptions and provide the relevant records through the agreed channel. Preserve the original evidence and clarification. Avoid requesting unnecessary technician personal information; the purpose is to understand the activity, not to collect an unrelated personnel file.

Compare service activity with purchases and stock records where these are relevant to the method. A refrigerant bought in one period may remain in storage. Material recovered from one unit may follow a different documented route. The evidence should support a coherent account of movements without assuming that all additions equal current-period leakage.

If records are incomplete, determine whether an appropriate screening or estimation method can be used and document why. Keep its uncertainty and limitations visible. Method selection should follow the actual tool guidance and competent review; this article does not provide a universal refrigerant mass-balance formula.

Assume an invented Singapore facilities team receives an invoice for two refrigerant cylinders and a separate note stating that several units were serviced. Neither record links a measured addition to an individual unit. No actual refrigerant, quantity or client is represented in this example.

The team cannot conclude that both cylinders were emitted. It asks the contractor to reconcile the quantities delivered, used and remaining, and to identify any recovered material. The inventory owner then chooses the method supported by the clarified evidence or records a justified estimate and its limitation.

If the team has already reported a provisional figure, it keeps a correction record rather than quietly replacing the number. The important outcome is a defensible calculation boundary, not the appearance of a complete spreadsheet.

The following fictional stock record uses kilograms of one identified refrigerant on a consistent measurement basis. It is a records exercise, not a handling procedure or a leakage calculation.

The stock balance is 5 + 20 − 12 = 13 kg. It explains where the purchased refrigerant went, assuming no other stock movements. It does not establish that 12 kg leaked in the period: additions may include charging newly installed equipment or other movements that need classification under the chosen method.

Suppose the contractor also recovered 3 kg into a separate recovery cylinder. Record that stock separately, with its destination and condition; do not add it to usable stock or subtract it from releases without checking the method and full equipment boundary. A record that combines recovered and virgin material without explanation can balance mathematically and still misstate emissions.

The inventory owner's output is therefore a reconciled service-and-stock dataset plus a method decision. Only after that decision should the calculation use the relevant refrigerant identity and warming-potential basis. Every quantity here is invented; no leakage rate, refrigerant handling competence or actual emissions result is claimed.

Preserve method version, activity sources, refrigerant identity, units, applicable warming-potential basis and review decision. Check the current reporting framework's requirements rather than copying factors from an old workbook without review. Do not confuse a reduction in purchases with proof of a reduction in leakage.

Use Singapore reporting evidence for suppliers when preparing information for a Singapore reporting request, but establish the recipient's actual boundary and method. A corporate inventory, a building service record and a customer questionnaire can ask different questions. Refrigerant work itself should remain with appropriately authorised and competent personnel.

No. Establish the activity, boundary and method. Stock purchases and releases are different events.

Only if an appropriate method permits it and the assumptions are defensible. Label estimation and assess whether better evidence is needed for material sources.

The contractor supplies technical evidence, while the inventory owner remains responsible for the chosen reporting boundary and method, supported by competent review.

GHG Protocol refrigeration and air conditioning tool — Official tool description updated 20 March 2026. Describes sales, life-cycle-stage and screening approaches; not refrigerant-handling instructions.

GHG Protocol Corporate Standard — Revised Corporate Standard 2004; use with applicable amendments and Scope 2 Guidance. Inventory method, not universal reporting legislation.

QSE Advisory is part of the QSE Advisory brand family. Preparation included AI-assisted research and drafting. Examples are hypothetical.

This article is general information. Verify current requirements and seek qualified advice for your specific circumstances.

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