# How do I calculate the steam and emissions of warp sizing per kg of yarn?

Canonical: https://senseible.earth/answers/erode-sizing-unit-steam-per-kg-yarn

Sizing uses steam to cook the size and to dry the coated yarn on heated cylinders, plus some electricity. Take the boiler fuel and the sizing machine's kWh for a period, convert them to CO2, and divide by kilograms of yarn sized. Steam leaks and wet yarn can double the figure.

## What to count

- Boiler fuel: wood, coal, briquettes or PNG from invoices.
- Electricity for the sizing machine, size cooker and compressor x 0.710 kg CO2 per kWh.
- Starch and binders bought, as an upstream estimate.

## Steam per kg

If the boiler also serves other processes, split the fuel by steam flow meters or by the hours each user runs, and label the split.

## Where to save

Condensate return, insulated cylinders, controlled size pick up and better squeeze rolls cut the steam per kg of yarn.

## What Senseible does here

Senseible reads fuel, electricity and freight invoices into a dated, fingerprinted record per site, so each figure you send a buyer can be traced back to the documents behind it.

- [Powerloom vs airjet loom energy](https://senseible.earth/answers/powerloom-vs-airjet-loom-energy-per-metre)
- [Coal vs PNG vs biomass boilers](https://senseible.earth/answers/coal-vs-png-vs-biomass-boiler-emissions)
- [Spinning mill per kg yarn](https://senseible.earth/answers/spinning-mill-carbon-footprint-per-kg-yarn)

Sources: [IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults)](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [CEA CO2 Baseline Database, version 21.0](https://cea.nic.in/cdm-co2-baseline-database/?lang=en), [ISO 14067:2018, Carbon footprint of products (iso.org)](https://www.iso.org)

Last reviewed 2026-10-21.