# How do we measure steam for CBAM when part of the heat comes back as condensate?

Canonical: https://senseible.earth/answers/cbam-measurable-heat-net-of-return-flow

CBAM counts net measurable heat: the heat going into a process minus the heat that comes back, for example as condensate. Record the flow, temperature and pressure of the steam in and the state of what leaves. If the return flow differs or is unknown, you need a reasoned assumption for its enthalpy.

## What counts as measurable heat

Heat carried in a medium such as hot water, steam, heated oil or hot air, through pipes or ducts, where a heat meter is or could be installed. Anything else is non-measurable heat. Cooling made with an absorption chiller counts as a heat consumer too.

## What to record for each consuming process

You then work out enthalpy from steam tables or engineering software.

- Flow rate of the heat carrier, by volume or mass.
- State of the carrier going in: temperature, pressure, type, and for steam whether it is saturated or superheated.
- State of the carrier leaving the process.
- If the returned flow, such as condensate, differs from the forward flow or is unknown, a suitable assumption for its enthalpy.

## What else gets counted

- Heat used by the plant's own distribution network, such as deaerators, make-up water preparation and boiler blowdown, plus pipe losses.
- Heat imported from or exported to another process or installation, including a district network.
- Each consuming process separately, unless they belong to the same overall production process of the same good.

## Three methods, ranked

The Methodology Act gives three methods for heat made inside the installation. They run from best to weakest data quality, and method 1 is preferred over method 2, and method 2 over method 3. Pick the best one your instruments support and write it into the monitoring plan, with a regular check for added or removed heat users.

## What Senseible does here

Senseible reads your fuel, power and steam bills into verified emission records, so the monthly figures a monitoring plan needs are ready to hand to your verifier. Verified here means rule checks passed against the evidence. It is not third-party assurance, and a CBAM verifier still signs the report.

- [Steam from two boilers: what a verifier needs](https://senseible.earth/answers/cbam-steam-from-two-boilers-verifier-evidence)
- [Imported heat from a neighbouring plant](https://senseible.earth/answers/cbam-imported-heat-from-neighbouring-plant)
- [CBAM Suite](https://senseible.earth/cbam-suite)

Sources: [European Commission, CBAM Guidance No. 3, calculation of embedded emissions](https://taxation-customs.ec.europa.eu/document/download/29b9eec7-1a4b-4eb6-ab85-96a0c9e35fd0_en?filename=Guidance%20No.%203%20-%20CBAM%20methods%20for%20the%20calculation%20of%20emissions%20embedded%20in%20goods.pdf)

Last reviewed 2026-11-04.