For factories, manufacturing plants, hospitals, commercial facilities and other sites that depend on diesel backup power, an RECD system for industrial generators can be an important part of an emissions-control strategy for applicable existing DG sets. A retrofit project, however, should not be approached as simply buying a device and attaching it to an exhaust pipe. The generator's engine, gross mechanical power, selected RECD model, installation arrangement, supporting documentation, maintenance requirements and current regulatory requirements all need to be considered together.

CPCB has published a specific procedure for emission-compliance testing of Retrofit Emission Control Devices (RECDs) for diesel power-generating-set engines up to 800 kW gross mechanical power. The procedure was revised on July 24, 2023. For organizations planning an industrial DG retrofit in 2026, the safest approach is to verify the exact product and application and check the latest official requirements before making compliance-related decisions.

What Is an RECD for an Industrial Generator?

A Retrofit Emission Control Device is an emission-control system designed to be fitted to an existing diesel generator installation.

The purpose of an RECD is to reduce relevant pollutants from the generator's exhaust through a defined emission-control technology and configuration.

The actual design can vary between products. Depending on the system, an RECD may incorporate technologies or components intended to address particulate matter and gaseous emissions.

The important point for an industrial buyer is that the device should be evaluated as a complete engineered retrofit, not as a generic exhaust accessory.

Why Industrial Facilities Consider RECD Systems

Industrial generators are often used when grid power is unavailable, during emergencies, for backup operations or in situations requiring additional power reliability.

Replacing an existing DG set solely because of an emissions-control requirement can be a significant capital decision.

A retrofit approach may be considered where an applicable and documented RECD solution is available for the particular generator.

Potential reasons for evaluating an RECD include:

• Emissions-control planning

• Regulatory requirements applicable to the installation

• Retaining an existing DG asset

• Reducing particulate and other emissions

• Improving environmental management

• Developing a documented retrofit strategy

The exact reason should be established for each facility rather than assuming that every industrial DG has identical obligations.

Start With the Generator

The most important information for selecting an RECD comes from the generator itself.

Prepare a technical inventory containing:

• DG-set manufacturer

• Engine manufacturer

• Exact engine model

• Engine serial number

• Gross mechanical power

• DG rating in kVA

• Rated speed

• Exhaust-pipe diameter

• Existing silencer arrangement

• Installation location

• Number of operating DG sets

Also take clear photographs of the engine and DG nameplates.

This information allows the supplier to evaluate the actual application instead of recommending a generic RECD based only on the kVA rating.

Gross Mechanical Power Matters

CPCB's published RECD procedure specifically covers diesel power-generating-set engines up to 800 kW gross mechanical power.

CPCB's published RECD manufacturer information also identifies applicability using specific engine-power ranges and Phase classifications. The list currently available on CPCB's website is dated May 9, 2025.

Therefore, buyers should not assume that:

“A 500 kVA DG needs a 500 kVA RECD.”

The actual engine information should be reviewed before selecting the equipment.

How to Select the Right RECD

A good selection process involves matching several technical points.

Engine

Identify the exact engine manufacturer and model.

Power

Verify the gross mechanical power.

RECD

Identify the exact manufacturer, type and model.

Application

Confirm that the product's documented application covers the intended engine.

Installation

Check the existing exhaust arrangement and mounting requirements.

Documentation

Request the relevant technical and certification/test information.

CPCB's published procedure describes type approval and testing in relation to RECD types/families and engine applications.

This is why product-specific verification is more reliable than a general “CPCB-approved RECD” statement.

RECD Technology and Emission Control

Different RECD designs can use different emission-control technologies.

Depending on the system, technologies may include combinations involving:

• Diesel particulate filtration

• Diesel oxidation catalysts

• Selective catalytic reduction

• Regeneration systems

• Sensors

• Controllers

The exact configuration depends on the manufacturer and application.

For an industrial facility, ask the supplier to explain:

Which technologies are included?

Which pollutants are addressed?

What documentation supports the claimed performance?

What operating conditions are required?

Avoid comparing products solely by marketing terms such as “advanced,” “premium” or “high-efficiency.”

Installation Is Part of the Engineering

An industrial RECD installation needs to be compatible with the existing exhaust system.

The supplier should examine:

• Exhaust diameter

• Flange arrangement

• Silencer

• Pipe routing

• Available installation space

• Mounting points

• Structural supports

• Maintenance access

CPCB's RECD testing documentation includes exhaust back pressure among the technical considerations.

Therefore, installation should be planned using actual measurements rather than assumptions.

For a complicated facility, a pre-installation site survey is strongly useful.

What an Industrial Installation May Include

Depending on the supplier and project scope, installation can involve:

1. DG and engine verification

2. Site inspection

3. Exhaust measurement

4. Fabrication planning

5. Mounting arrangements

6. RECD installation

7. Relevant controller or sensor connections

8. Commissioning

9. Documentation

10. Operator handover

The exact scope should be written into the quotation or purchase order.

Industrial Site Conditions Matter

An RECD installed at a manufacturing plant may face different conditions from one installed at a commercial building.

Industrial projects can involve:

• Multiple DG sets

• Long exhaust routes

• Restricted working hours

• Hot-work permits

• Limited shutdown windows

• Large fabrication requirements

• Multiple contractors

The installation provider should understand these conditions before finalizing the schedule.

A technically appropriate device can still become difficult to operate if it is installed without considering future maintenance access.

Maintenance and Long-Term Operation

An RECD should be considered over its entire operating life.

Before purchasing, ask the supplier about:

• Inspection frequency

• Cleaning requirements

• Regeneration requirements

• Sensor checks

• Controller maintenance

• Replaceable components

• Recommended service intervals

• Spare parts

The exact requirements depend on the selected product, so the manufacturer's instructions should be used as the primary reference.

For a plant operating several generators, it is useful to maintain an individual service record for every RECD.

Documentation Should Be Part of the Project

Keep a complete file for each installation.

DG Documentation

• Engine nameplate

• DG nameplate

• Engine model

• Gross mechanical power

RECD Documentation

• Manufacturer

• Model/type

• Serial number

• Technical datasheet

• Relevant supporting documents

Installation Documentation

• Site survey

• Installation report

• Fabrication details

• Commissioning report

• Photographs

Commercial Documentation

• Quotation

• Purchase order

• Invoice

• Warranty

This creates traceability for future service and internal technical audits.

How to Evaluate RECD Manufacturers in India

When comparing RECD manufacturers in India, don't rank companies solely by advertising, price or online visibility.

CPCB's published manufacturer list provides useful information about manufacturers certified for RECDs applicable to diesel genset engines up to 800 kW, including documented engine-power ranges, Phase applicability and certification agencies.

Use that information as one part of your evaluation.

Then compare:

• Exact product applicability

• Engine range

• Product documentation

• Installation support

• Warranty

• Spare parts

• Service network

• Delivery

• Total project cost

A manufacturer may have a broad product range but still require a specific model for your generator.

What Does “CPCB Approved” Actually Tell You?

This phrase should be handled carefully.

CPCB's official procedure provides the framework for emission-compliance testing and type approval of applicable RECDs.

However, a general statement such as:

“CPCB-approved RECD”

should not be treated as sufficient information.

Ask:

• Which manufacturer?

• Which exact model?

• Which engine/application?

• What documentation supports the product?

• Which certification agency is identified?

• What current requirements apply to the site?

Product certification and overall site compliance are not automatically identical.

Compliance Is Not the Same as Installation

An industrial facility should avoid assuming:

RECD purchased = compliance completed

The actual regulatory position may depend on:

• DG specifications

• Engine

• RECD model

• Installation

• Location

• Current requirements

• Applicable State/UT directions

• Site-specific conditions

Therefore, regulatory claims should be checked against current official sources.

CPCB also maintains a Generator Sets section containing Type Approval/COP information.

For a 2026 project, use the latest official CPCB publications available at the time of procurement.

How Much Does an Industrial RECD Project Cost?

There is no single price applicable to every industrial generator.

The final cost can include:

RECD equipment

Fabrication

Installation

Transportation

Commissioning

Warranty/service

Applicable taxes or other project charges

Factors affecting the quotation can include:

• Engine power

• RECD model

• Exhaust configuration

• Site location

• Number of DG sets

• Installation complexity

• Quantity ordered

• Service requirements

For this reason, industrial customers should request DG-specific quotations instead of relying on generic online pricing.

Practical Industrial RECD Checklist

Before approving the project:

Technical

• Engine model verified

• Gross mechanical power confirmed

• RECD model identified

• Application range checked

• Exhaust arrangement reviewed

Product

• Manufacturer verified

• Datasheet received

• Relevant supporting documentation reviewed

• Product-specific certification information checked

Installation

• Site survey completed

• Fabrication scope defined

• Installation responsibility defined

• Commissioning included

• Maintenance access planned

Commercial

• Complete quotation received

• Transportation confirmed

• Warranty documented

• Spare-parts support reviewed

• Service coverage confirmed

Compliance

• Current CPCB information verified

• Applicable State/UT requirements checked

• Site-specific requirements reviewed

• No unsupported compliance claims accepted

Final Thoughts

An RECD system for industrial generators should be treated as a technical retrofit project rather than simply another piece of exhaust equipment. The process should begin with the generator: identify the engine, verify gross mechanical power and understand the existing exhaust arrangement. Then select an appropriate RECD model, review its documentation and plan the installation around the actual site. CPCB's published procedure establishes the emission-compliance testing and type-approval framework for applicable RECDs for diesel power-generating-set engines up to 800 kW gross mechanical power. CPCB's published manufacturer information provides additional product-applicability information by engine-power range, Phase and certification agency. For buyers comparing RECD manufacturers in India, official manufacturer information should be used as a starting point rather than as a complete ranking. The final selection should consider the exact DG application, product documentation, installation capability, warranty, service and total project cost. The right RECD is not simply the one that fits the exhaust pipe. It is the one that is appropriately matched to the DG application, properly documented, correctly installed and supported throughout its operating life.