How do I calculate the steam and emissions of warp sizing per kg of 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.
Sources: IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0, ISO 14067:2018, Carbon footprint of products (iso.org)
Last reviewed 2026-10-21.