# How much fuel does a three pass boiler save over a single pass boiler in a Panipat textile unit?

Canonical: https://senseible.earth/answers/panipat-single-pass-boiler-48-60-percent-efficiency

A three pass boiler with heat recovery saves 15 to 27% of fuel over a single pass one, says the Panipat energy survey by The Energy and Resources Institute (TERI). The old boilers ran at 48 to 60% efficiency. The survey prints a payback of up to 18 months.

## What a single pass boiler is, in plain words

A boiler is a big kettle. Fuel burns in a furnace, and the hot gas heats water in tubes to make steam. A pass is one trip of the hot gas through the boiler.

In a single pass boiler the gas goes through once and leaves up the chimney, still hot. In a three pass boiler it turns back twice, so the water takes more of the heat. TERI says the single pass type has higher heat losses and poor quality of steam, and that most boilers in the cluster are three pass. Only a few smaller units use single pass.

## What the survey table prints

- Existing boiler: single pass, efficiency 48 to 60%.
- Proposed: a three pass boiler with a heat recovery mechanism.
- Energy saving potential: 15 to 27%. Simple payback: up to 18 months.
- The table gives no boiler size and no cost, so the 18 months cannot be checked from the page.

## What efficiency means, and what the saving implies

Efficiency is the share of the fuel’s heat that ends up in the steam. The rest leaves through the chimney or the boiler shell. For the same steam, fuel needed = steam heat ÷ efficiency. So fuel saved = 1 − old efficiency ÷ new efficiency.

Our reading, not the survey’s: the survey prints no new efficiency. If the 48% boiler saved 27%, the new one would run at 48 ÷ 0.73 = 65.8%. If the 60% boiler saved 15%, the new one would run at 60 ÷ 0.85 = 70.6%. The table does not say which old figure goes with which saving, so treat these as a check on plausibility only.

## Before you order

- Find out which type you have. Count the passes on the maker’s drawing or plate.
- Ask for the efficiency the maker will guarantee on your fuel, wood or pet coke, at your usual steam load.
- Use 12 months of fuel invoices as the baseline, and compare the same months after the change.

## Example: a unit burning 30 tonnes of wood a month

- Saving at 15%: 30 × 0.15 = 4.5 tonnes a month, 54 tonnes a year
- Saving at 27%: 30 × 0.27 = 8.1 tonnes a month, 97.2 tonnes a year
- TERI says the few single pass boilers are in smaller units, which burn biomass such as wood or upla. The Greenhouse Gas (GHG) Protocol says direct CO2 from burning biomass shall not be included in Scope 1 (the fuel you burn yourself) but reported separately.

Example only. If you burn pet coke, a hard black fuel left over from refining oil, the Intergovernmental Panel on Climate Change (IPCC) defaults give about 3.17 tonnes of carbon dioxide (CO2) for each tonne: 32.5 gigajoules a tonne x 97.5 kilograms of CO2 a gigajoule. Your invoices give your own figure.

## What Senseible does here

Senseible reads your fuel invoices into monthly records, giving you twelve months of fuel bought to use as the baseline. It does not read a boiler, so the efficiency a maker guarantees has to be checked on your own boiler.

- [Green loan readiness check](https://senseible.earth/green-loan-check)
- [Panipat fuels and carbon](https://senseible.earth/answers/panipat-textile-cluster-fuels-and-carbon)
- [Boiler efficiency, direct and indirect method](https://senseible.earth/answers/boiler-efficiency-direct-and-indirect-method)
- [Surat boiler measured at 36%, costed from 60%](https://senseible.earth/answers/surat-boiler-measured-36-percent-costed-from-60-percent)

Sources: [TERI, Energy Profile: Panipat Textile Cluster, 2016 (SAMEEEKSHA)](https://sameeeksha.org/pdf/clusterprofile/PanipatTextileCluster.pdf), [IPCC, 2006 Guidelines for National Greenhouse Gas Inventories, Volume 2, Energy](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [Greenhouse Gas Protocol, Corporate Accounting and Reporting Standard](https://ghgprotocol.org/corporate-standard)

Last reviewed 2026-11-07. Figures are from the Panipat survey of 2014-15, published in 2016. The survey table prints each saving as a range with no boiler size, fuel tonnes or equipment cost. Check a current quote and your own fuel records before you rely on any payback.