# How much electricity does a VFD on a thermic fluid pump save in a textile processing house?

Canonical: https://senseible.earth/answers/thermopac-pump-vfd-electricity-saving

About 77,600 kWh a year, close to half the pump's power, in BEE's Pali report: a VFD trims a 23 kW thermic fluid pump from 120 to 96 m3 an hour. Cost Rs 1.75 lakh, saving Rs 3.57 lakh at Rs 4.60 a kWh, payback about 6 months (2010). CO2 falls about 52 t on today's grid.

## Why the pump is oversized

- The pump runs 24 hours to keep the fluid moving, so it is often the biggest single motor in a Pali process house: rated 20 or 30 kW, drawing 16 or 23 kW.
- Stenters (rated 4 lakh kcal an hour, running near 3) and printing dryers take less heat than the thermopac can give, and their valves bypass hot fluid when a chamber is hot enough.
- So the pump pushes more fluid than the load needs, all day. BEE found no VFD on any thermic fluid pump in Pali.

## The saving, step by step

- Now: 23 kW x 24 hours x 300 days = 165,600 kWh.
- With the VFD and PLC: flow 120 to 96 m3 an hour, 80%. Pump power falls with the cube of flow, 0.8 x 0.8 x 0.8 = 0.51, so 84,787 kWh.
- The drive itself uses about 3,232 kWh. Net saving 77,578 kWh, Rs 3.57 lakh.
- Cost: Rs 1.5 lakh drive and controls, Rs 0.25 lakh fitting. One to two days of downtime.

## Two checks before you fit it

- Minimum flow: the heater coils need a minimum fluid velocity or the oil cracks and cokes. Get that figure from the thermopac maker and set it as the drive's floor.
- The cube rule works when pipe friction is most of the pump's head. Where valves hold a fixed pressure, savings are lower. Meter the pump for a week after fitting.

## One thermopac pump, one year

- Saving: 165,600 less 84,787 less 3,232 = 77,581 kWh; the report prints 77,578
- Money: 77,578 x Rs 4.60 = Rs 3.57 lakh; payback 1.75 / 3.57 = 0.49 years
- CO2: 77,578 x 0.675 = 52.4 t a year
- The report's 65 t used an older grid factor

Grid at CEA's FY 2025-26 factor of 0.675 kg CO2 a kWh, an estimate.

## What Senseible does here

Senseible reads electricity bills into monthly records with CO2, so a 77,000 kWh drop shows in the months after the drive goes in. The green loan check shows what a lender asks for on a VFD loan.

- [Green loan readiness check](https://senseible.earth/green-loan-check)
- [Green loans for VFDs on pumps and fans](https://senseible.earth/answers/green-loan-vfd-on-pumps-and-fans)
- [VFD savings on pumps and fans](https://senseible.earth/answers/vfd-pump-fan-energy-co2-savings)
- [Thermopac air preheater: pet coke saved](https://senseible.earth/answers/thermopac-air-preheater-petcoke-saving)

Sources: [BEE, Detailed project report: VFD in thermic fluid pump of thermopac, Pali textile cluster (2010, SAMEEEKSHA)](https://sameeeksha.org/pdf/dpr/pali_thermopac.pdf), [CEA CO2 Baseline Database, version 22.0](https://cea.nic.in/cdm-co2-baseline-view?mappingId=234&lang=en)

Last reviewed 2026-10-31. Report figures are from a BEE SME programme project report; costs and tariffs are at 2010 prices. Check your tariff and a current quote.