How to Write a Technical RFQ for an RECD Project

Most RECD purchases go wrong long before anyone touches a spanner. They go wrong on the day a facility manager sends three vendors a WhatsApp message that says “Need RECD for 500 kVA DG, send best rate.” Three quotations come back. One is for a device sized on kVA alone, one quietly excludes exhaust modification, and one assumes the generator runs at full load all day. None of them can be compared, and the cheapest one is cheap for reasons nobody can see.

A technical Request for Quotation (RFQ) fixes that. It forces every bidder to price the same job, answer the same questions and commit to the same outcomes in writing. This guide walks you through building an RFQ for a Retrofit Emission Control Device project from a blank page, section by section, with sample wording you can adapt for your own site.

If you are still getting familiar with the device itself, start with our explainer on what an RECD is and how it works and come back here when you are ready to buy.

Why a Technical RFQ Matters More for RECDs Than for Most Equipment

An RECD is not a catalogue item you can pick off a shelf. It bolts into the exhaust path of a running engine, so its suitability depends on the engine’s exhaust flow, temperature, permissible back pressure, duty cycle and the physical space around the generator. Two DG sets with the same kVA rating can need different devices, a point we explore in why same-kVA DG sets may need a different RECD.

That has three consequences for procurement:

• Price alone tells you very little. A lower quote may reflect a smaller device, less site work or a weaker warranty, not a better deal.
• The compliance outcome is what you are really buying. Regulators care that particulate emissions fall by the required margin and that the engine is not harmed. Your RFQ should make bidders promise that outcome, not just deliver a box.
• Risk sits at the joints. Exhaust modification, structural support, testing and paperwork are where scope gaps hide. An RFQ is the cheapest place to close them.

A well-written RFQ also protects you later. If a pollution control officer asks how the device was selected, the RFQ and the bidder’s signed technical responses form a clean audit trail.

Step Zero: Assemble Your Pre-RFQ Data Pack

Bidders can only quote accurately on what they can see. Before drafting anything, collect the following for every generator in scope. Treat this pack as an annexure that travels with the RFQ.

Generator identity

• Clear photographs of the DG nameplate and the engine nameplate (they are often different plates). Our guide on which nameplate photos to share for an RECD enquiry shows exactly what bidders need.
• Make, model, kVA/kW rating, engine serial number and year of manufacture.
• Emission norm the set was built to (CPCB-I, CPCB-II and so on), if known.
• Whether the engine is turbocharged or naturally aspirated, and mechanically or electronically governed.

If original documents are missing, say so plainly rather than guessing. There is a practical route for that situation, covered in specifying an RECD when DG set documents are missing.

Operating profile

• Typical and peak load as a percentage of rating.
• Average running hours per month and the longest continuous run.
• Standby, prime or continuous duty.
• Any planned load additions over the next five years.

Real data beats estimates. Even a month of readings helps, and our article on using DG load logs to assess RECD suitability explains what to record.

Exhaust and site layout

• A sketch or drawing of the existing exhaust route from the manifold to the stack outlet, with pipe diameters, bends and lengths.
• Location of the silencer, flexible bellows and any rain cap.
• Photographs of the DG room, canopy or rooftop, with access routes for lifting equipment.
• Ceiling heights, wall construction and floor loading where the device may be mounted.

Engine data from the OEM

• Exhaust gas flow rate and temperature at rated load.
• Maximum permissible exhaust back pressure.

These two numbers drive device sizing more than anything else. If you do not have them, ask the generator dealer before issuing the RFQ, or require bidders to obtain them. See why OEM exhaust flow data matters when specifying an RECD.

The Anatomy of a Strong RECD RFQ: Ten Sections

The structure below works for a single housing society generator and scales up to a multi-site corporate tender. Each section includes what it must achieve and an example clause written in plain language.

Section 1: Purpose and Background

Explain why you are buying. State the site, the number of generators and the regulatory driver, such as a directive from the State Pollution Control Board or air quality restrictions in your region. This helps bidders flag issues you may not have considered.

Sample clause: “The Purchaser operates two diesel generator sets at its premises in Noida and intends to retrofit each with an emission control device that achieves the particulate reduction required by CPCB for in-use gensets, without adverse effect on engine performance, so that the sets remain usable during periods of air-quality-linked restrictions.”

Section 2: Scope of Supply and Services

Spell out whether you want the device only, the device plus supervision, or a full supply-installation-testing-commissioning (SITC) package. Ambiguity here causes more disputes than any other clause. If you are unsure which model suits you, read our comparison of supply-only vs turnkey RECD orders.

List included activities explicitly: site survey, design, fabrication of adapters, removal and reinstatement of existing pipework, structural supports, lifting, insulation, testing, documentation and training. Then list exclusions you know about, and invite bidders to declare their own.

Sample clause: “Any activity, material or service not expressly listed as excluded in the Bidder’s offer shall be deemed included in the quoted price.”

Section 3: Site and Equipment Data

Attach the pre-RFQ data pack. Reference each annexure by number so bidders cannot claim they did not receive it. Offer a site visit window and make attendance either mandatory or strongly recommended. Physical inspection reveals obstructions that drawings miss.

Section 4: Technical Performance Requirements

This is the heart of the RFQ. State outcomes in measurable terms: particulate matter reduction percentage, the effect on other regulated pollutants, maximum allowable added back pressure, noise impact and operating temperature range. Do not write “high efficiency device” or “minimal back pressure”. Write numbers, conditions and test methods.

Because this section deserves its own detailed treatment, we have written a separate guide to defining measurable RECD tender specifications. At a minimum, require:

• Minimum particulate matter reduction consistent with the CPCB requirement for retrofit devices (currently a minimum of 70%), demonstrated by a recognised testing agency.
• No adverse increase in other regulated emissions.
• Added back pressure that keeps total exhaust back pressure within the engine OEM’s declared limit at rated load.
• Suitability for the declared load profile, including low-load operation where relevant.

Section 5: Certification and Compliance Documents

Ask for documents that prove the device is legitimately approved for the engine power band you are buying for. Typically this means a type approval or certificate of conformity issued by a CPCB-recognised agency such as ICAT or ARAI, along with the test report.

Do not accept a certificate at face value. Check that the power range, model reference and manufacturer name match the offered product. Our walkthrough on how to read an RECD test certificate and the companion guide on verifying a CPCB-tested RECD cover the common traps.

Sample clause: “The Bidder shall submit a valid type approval certificate covering the power rating of each generator listed in Annexure A. Offers for devices whose certified range does not include the listed rating will be treated as non-responsive.”

Section 6: Installation Requirements

Describe constraints the installer must respect: permitted working hours, shutdown windows, hot work permits, housekeeping, safety equipment and the maximum duration the generator may be offline. Hospitals, data centres and hotels may need phased work around critical backup cover.

Specify the mounting approach if you have a preference (floor-supported, wall-mounted, rooftop) and require the bidder to confirm service access around the device. Practical considerations are covered in our guides on service clearance around an RECD and horizontal vs vertical mounting.

Section 7: Testing, Commissioning and Acceptance

State how you will decide the job is finished. A good acceptance regime includes:

• Back pressure measurement before and after installation at a defined load.
• A functional run at specified load points for a specified duration.
• Visual inspection of welds, flanges, supports and insulation.
• Any emission measurement required by your pollution control board, and who arranges and pays for it.

Sample clause: “Acceptance shall be granted only after the generator has run at not less than 50% of rated load for a continuous period of two hours with the device installed, and the measured exhaust back pressure remains within the OEM limit stated in Annexure C.”

Section 8: Warranty, Maintenance and Support

Ask for the warranty period, what it covers, what voids it, recommended maintenance intervals and the cost of consumables or cleaning. Treat claims like “zero maintenance” with care. Our article on what a maintenance-free RECD claim actually means explains what to ask.

Request response times for breakdown calls and the location of the nearest service team. Ask whether an annual maintenance contract is offered and at what rate.

Also ask the bidder to state in writing whether fitting the device affects the generator’s OEM warranty. Background on this is in will installing an RECD affect your generator’s OEM warranty.

Section 9: Commercial Terms

Keep commercial and technical bids separate if you can, so technical evaluation is not influenced by price. Specify:

• Price basis (ex-works, delivered, installed) and tax treatment.
• Payment milestones linked to delivery, installation and acceptance rather than order placement alone.
• Validity of the offer.
• Delivery and completion timelines from purchase order.
• Liquidated damages for delay, if appropriate.
• Retention or performance guarantee during the warranty period.

Ask bidders to fill your format of Bill of Quantities instead of their own, so line items match across offers. We explain how to build one in preparing a Bill of Quantities for an RECD retrofit.

Section 10: Submission Instructions and Evaluation Method

Tell bidders what to submit, in what format, by what date and to whom. Publish your evaluation method in advance. A simple approach is technical qualification first (pass or fail against mandatory requirements), then commercial comparison among qualified bidders only. For larger projects, a weighted score combining technical merit and price may suit better.

Public sector buyers will usually route this through GeM or the Central Public Procurement Portal and follow their organisation’s procurement rules. Private buyers have more freedom, but publishing the method still improves bid quality.

The Technical Questionnaire: Questions Every Bidder Must Answer in Writing

A questionnaire turns marketing claims into commitments. Include it as a mandatory form and treat a blank answer as non-compliance.

Question	Why it matters
What is the device model, and what certified power range does it cover?	Confirms the device is approved for your generator size.
What exhaust flow and temperature did you use to size the device?	Shows whether the bidder used your engine data or guessed.
What added back pressure do you predict at rated load, and how was it calculated?	Excess back pressure can raise fuel use and engine temperatures.
What is the minimum exhaust temperature or load needed for the device to perform as intended?	Critical for standby sets that run lightly loaded.
What maintenance does the device need, at what interval, and at what cost?	Reveals true ownership cost beyond the purchase price.
What exhaust modifications are required, and are they included in your price?	Exposes hidden scope.
How will the device be supported, and what loads will it place on the structure?	Prevents stress on the turbocharger, manifold or building.
How long will the generator be offline during installation?	Helps you plan backup cover.
What documents will you hand over at completion?	Ensures you can satisfy an inspection.
List three comparable installations with contact details.	Allows reference checks.

For low-load generators, the minimum temperature question is especially important. See choosing an RECD for a generator running at low load.

Writing Style Rules That Make an RFQ Enforceable

How you write matters as much as what you write. A few habits keep the document tight:

• Use “shall” for mandatory requirements and “should” for preferences. Then explain which words carry which weight in a definitions clause.
• Number every clause. Bidders can then reference specific clauses in their deviations list.
• Ask for a deviations schedule. Every bidder lists where their offer departs from your RFQ. Anything not listed is treated as compliant.
• Avoid brand names unless you will accept equivalents. Name a technology or outcome, not a manufacturer, unless there is a genuine compatibility reason.
• Put numbers in tables. Performance limits buried in paragraphs get missed.
• Keep one source of truth. If you issue clarifications, number them and state that they form part of the RFQ.

Comparing Quotations Like-for-Like

Once offers arrive, normalise them before comparing price. Build a comparison sheet with one column per bidder and rows for each mandatory requirement, each BoQ line and each questionnaire answer.

Look for these mismatches

• Different device sizes. If one bidder offers a device rated for a higher exhaust flow, it may cost more but run with lower back pressure.
• Excluded items. Add an estimated cost for anything one bidder excludes and others include.
• Different warranty terms. A two-year comprehensive warranty is worth more than a one-year parts-only warranty.
• Different maintenance costs. Calculate a five-year cost of ownership, not just the purchase price. Our guide on RECD cost in India gives realistic ranges.
• Unclear testing responsibility. If one bidder includes emission testing coordination and another does not, adjust accordingly.

A simple scoring approach

For a private site, a practical weighting might be 50% technical compliance and engineering quality, 30% five-year cost of ownership, and 20% service capability and references. Adjust to suit your priorities. A hospital may weight service capability higher; a cost-sensitive warehouse may weight price higher.

Guidance on assessing the vendor behind the device is in our article on choosing among CPCB-approved RECD vendors.

Red Flags in RFQ Responses

Some responses should prompt a follow-up call or disqualification:

• A certificate that covers a different power range or a different manufacturer.
• Refusal to state predicted back pressure in numbers.
• A price far below the others with no explanation.
• “Installation charges extra as per actuals” with no rate schedule.
• No site visit despite a complex exhaust route.
• Claims of fuel savings or power gains that the device cannot plausibly deliver. Our article on whether an RECD changes a generator’s usable power output explains what to expect.
• Vague answers on who arranges post-installation emission testing.

A Realistic RFQ Timeline

Rushing an RFQ usually costs more time later. A typical sequence for a single site looks like this:

1. Week 1: Collect the data pack, including OEM exhaust data.
2. Week 2: Draft and internally review the RFQ.
3. Week 3: Issue the RFQ and hold site visits.
4. Week 4: Answer clarification questions in a single consolidated note.
5. Week 5: Receive offers and run technical evaluation.
6. Week 6: Commercial negotiation and purchase order.

Installation then follows the vendor’s lead time. For what happens after the order, see our RECD installation timeline and the step-by-step installation guide.

If you are in Delhi NCR and working against seasonal restrictions, start earlier. Our summary of GRAP rules for DG sets explains why the autumn window matters.

Special Situations Your RFQ Should Address

Multiple generators

Provide one data sheet per generator and ask for prices per set. Do not let bidders lump everything into one figure. Generators of different ages or load profiles may need different devices.

Generators with existing aftertreatment

If a set already has a DPF or SCR, say so. The approach changes. Read adding an RECD to a generator with existing DPF or SCR.

Old or heavily used engines

High oil consumption or poor combustion can affect device performance. Ask bidders whether they recommend an engine health check first. Related reading: should you complete an engine overhaul before fitting an RECD.

Space-constrained sites

Basements, rooftops and acoustic canopies each create specific challenges. Mention them in Section 3 and ask bidders to explain their solution. See our notes on basement installations and whether an RECD can fit inside an existing canopy.

A Short RFQ Checklist Before You Hit Send

• Every generator has a complete data sheet with nameplate photos.
• OEM exhaust flow, temperature and back pressure limits are attached or requested.
• Scope states included and excluded items, with a deemed-inclusion clause.
• Performance requirements are numeric and testable.
• Certification requirements name the document type and coverage.
• Acceptance tests are defined with load, duration and pass criteria.
• Warranty, maintenance and response times are requested in writing.
• The BoQ format is fixed and mandatory.
• The evaluation method is published.
• Submission deadline, format and contact person are clear.

Frequently Asked Questions

Is an RFQ necessary for a single small generator?

For a single small set, a short RFQ of two or three pages is still worth it. Even a one-page data sheet plus a list of mandatory requirements gives you comparable quotes and a record for compliance purposes.

Should I name a specific RECD technology in the RFQ?

Generally no. Specify outcomes such as particulate reduction, back pressure limits and maintenance requirements, and let bidders propose the technology that meets them. Name a technology only if your site has a genuine constraint that rules others out.

How many vendors should receive the RFQ?

Three to five qualified vendors is usually enough for a private buyer. Too few limits competition; too many creates evaluation work without improving outcomes. Pre-screen vendors for valid certification before sending.

Who should obtain the OEM exhaust data?

Ideally the buyer, because the generator dealer has a relationship with you. If that is not practical, make obtaining it a bidder responsibility and require them to state the source in their technical response.

Can I negotiate after receiving quotes?

Yes, but negotiate on an equal basis. If you clarify scope with one bidder, share the clarification with all. Otherwise you lose the like-for-like comparison the RFQ was built to create.

Final Thoughts

A technical RFQ is a few days of work that saves months of argument. It turns a vague purchase into a defined engineering job with measurable results, and it gives every bidder the same chance to compete on substance rather than on how cleverly they can hide exclusions.

If you would like a vendor to review your data pack or respond to your RFQ, explore Aceget’s retrofit emission control devices, check our certifications, or contact our team for a site-specific proposal.