Does heat setting on a stenter use more energy per tonne than drying on it, and where do scouring and bleaching sit?

The Bureau of Energy Efficiency (BEE) Pali manual prints stenter drying at 2.5 to 7.5 gigajoules (GJ) a tonne and stenter heat setting at 4.0 to 9.0. Scouring and bleaching run from 1.5 to 10.0 by machine. The ranges overlap from 4.0 to 7.5, so the process does not settle it.

The rows as printed

• Stenter, drying: 2.5 to 7.5 GJ a tonne. Stenter, heat setting: 4.0 to 9.0. Steam cylinders, drying: 2.5 to 4.5.
• Desizing unit: 1.0 to 3.5. Kier, scouring or bleaching: 6.0 to 7.5. J-box, scouring: 6.5 to 10.0.
• Open width range, scouring or bleaching: 3.0 to 7.0. Low energy steam purge, scouring or bleaching: 1.5 to 5.0.
• Jig or winch, scouring: 5.0 to 7.0. Jig or winch, bleaching: 3.0 to 6.5. Continuous hank, scouring: 3.0 to 5.0.
• The manual credits the table to Carbon Trust of the United Kingdom, with no year and no note on heat only or heat plus power.

Drying against heat setting

Heat setting fixes a synthetic fabric's size and shape at a high temperature, and the table puts it higher at both ends: floor 4.0 against 2.5, ceiling 9.0 against 7.5. The midpoints are 6.5 and 5.0, our arithmetic. The ranges overlap from 4.0 to 7.5, so a stenter drying cotton badly can use more per tonne than one heat setting well.

In kilowatt hours (kWh) a kilogram, drying is 0.69 to 2.08 and heat setting 1.11 to 2.50, using 1 GJ a tonne = 0.278 kWh a kilogram.

Why the same stenter varies

• The energy balance table prints evaporation 41% and air heating 39.7%; a later example calls 39.7% the evaporation efficiency. Either way, most of the heat does not dry the cloth.
• The manual's own stenter examples turn on how wet the fabric enters, how far it is dried past its natural moisture and the exhaust air, so two tonnes of different fabric are not the same task.
• On the same range, a stenter heated by coke, coal or wood has different carbon from the same GJ, so the carbon follows the fuel, not the GJ.

Using it in your records

1. Meter or estimate the stenter's share of the heater fuel, as in the page linked below.
2. Divide by tonnes dried or set, and keep drying and heat setting runs apart if you can.
3. Compare with the row for your process; above the ceiling suggests an air or insulation loss to look for.

Per metre from the manual's ranges

• Thin polyester at 80 g a metre: 12.5 metres a kilogram, so 1 tonne = 12,500 metres
• Heat setting at 6.5 GJ a tonne (midpoint): 6.5 GJ / 12,500 = 520 kilojoules a metre = 0.144 kWh a metre
• Range: 4.0 to 9.0 GJ a tonne = 0.089 to 0.200 kWh a metre

The 80 g a metre is an example weight; the Pali manual says its cluster mostly uses fabric below 100 grams a metre. The per metre figures are our own conversion of the printed range.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so heater fuel and electricity for the month are on file. The stenter's own share needs a heat meter or hours logged on the heater.

• Stenter fuel and CO2 per metre of fabric
• Stenter residual moisture control
• Pali manual: dyeing energy per tonne by machine
• Free calculators

Sources: Bureau of Energy Efficiency and Petroleum Conservation Research Association, Cluster Manual, Pali Textile Cluster (via SAMEEEKSHA)

Last reviewed 2026-11-05. The ranges are as printed in BEE's Pali manual from another publisher's table, with no year given. Check them against your own metered figures.