How to Evaluate a Vendor’s RECD Reference Installation

Every RECD vendor has a list of satisfied customers. The list usually arrives as a slide with a dozen logos, a few kVA ratings and the words “successfully installed and running.” It looks reassuring. It tells you almost nothing.

A reference installation is only useful when it answers the question you actually have: will this vendor’s device, fitted by this vendor’s team, keep working on a generator like mine, in conditions like mine, for as long as I need it to? A logo cannot answer that. A properly examined site can.

This guide walks through how to evaluate a vendor’s RECD reference installation in a structured way, from screening the reference list at your desk, to speaking with the site owner, to standing in front of the device with a torch. It also covers how to score what you find, how to handle references that do not perfectly match your generator, and how to record the result so your procurement file holds up when someone asks why you chose this vendor.

Why a Reference Installation Carries More Weight Than a Brochure

A Retrofit Emission Control Device is not a shelf product. Its performance depends on the engine it sits behind, the load profile of the generator, the exhaust layout and the quality of the fitment. If you are new to the technology, our explainer on what an RECD is and how it works covers the fundamentals.

Two documents are normally offered as proof of quality: the type approval or test certificate, and the reference list. They prove different things.

• The certificate proves that a device model met the particulate matter capture requirement under controlled test conditions at an approved agency such as ARAI or ICAT. Our guide on how to read an RECD test certificate explains what each field means.
• The reference installation proves (or fails to prove) that the vendor can turn that certified model into a working system on a real generator, and keep it working after the installation team has left.

Most RECD problems buyers face in the first two years are not certification problems. They are fitment, backpressure, support, access and service problems. Those only show up in the field. That is exactly why the reference visit matters.

The Three-Gate Method for Reference Evaluation

Treat reference evaluation as three gates. A reference that fails an early gate does not need the effort of a later one.

1. Gate 1, desk screening: Is this reference relevant to my generator and site at all?
2. Gate 2, owner conversation: What does the person living with the device say about it?
3. Gate 3, site inspection: Does what I see on the ground match what I was told?

The rest of this guide takes each gate in turn.

Gate 1: Screening the Reference List at Your Desk

Ask the vendor for a reference list in a structured format rather than a slide. You want one row per installation with the information below. A vendor that cannot produce this for its own installations is telling you something about its record-keeping, and record-keeping is what you will depend on when you need spares or a compliance document three years from now.

Field to request	Why it matters
DG set rating (kVA / kW) and engine make	Device sizing and exhaust flow are engine-specific
Engine model and aspiration type	Turbocharged and naturally aspirated engines behave differently
Application (standby, prime, continuous)	Running hours and load drive soot loading
Date of commissioning	Tells you how long the device has been in service
Approximate annual running hours	A device that ran 40 hours a year has not been tested
Installation location (basement, rooftop, open yard, canopy)	Access and environmental exposure
Site contact name and role	You need someone who operates it, not just someone who signed the PO
Whether the vendor still services the site	Indicates whether the relationship survived installation

How to Match a Reference to Your Own Generator

Filter the list for installations that resemble yours on the factors that actually change RECD behaviour. Rating alone is not enough; two sets of identical kVA can need very different devices, a point covered in detail in our article on why same-kVA DG sets can need different RECDs.

In order of importance, look for similarity in:

• Engine family and displacement band. This drives exhaust volume and temperature. See how engine displacement affects RECD selection.
• Load profile. A set that idles at 20 to 30 percent load for most of its life produces cooler, wetter exhaust and more soot than one running at 70 percent. If your set runs light, read choosing an RECD for a generator running at low load before you compare.
• Duty pattern. Frequent short starts are harder on a device than long steady runs.
• Environment. Dust, salt air and high ambient heat each create distinct failure modes.
• Age of the reference. Prefer installations that have been in service for at least one full year, ideally through a full winter season of heavy use.

The Shortlist Rule

You need two or three relevant references, not ten. Pick at least one that is close to your setup and at least one that has been running the longest. If the vendor has nothing close to your engine family, that is not automatically disqualifying, but it shifts weight onto technical evidence such as backpressure calculations and the type approval coverage of your engine.

Gate 2: Talking to the Reference Owner

Vendors often offer to “arrange” a reference conversation. Accept the introduction, then speak to the site contact privately. The most useful person is the one who operates or maintains the generator day to day: a facility engineer, a maintenance supervisor or the DG operator. The person who approved the purchase knows the price; the person in the plant room knows the truth.

Keep the call to fifteen or twenty minutes. Busy engineers will give you their time if you are specific. Group your questions around five themes.

Theme 1: The Installation Experience

• How long did the installation take compared with what was promised?
• Was the generator unavailable for longer than planned?
• Did the vendor’s team bring everything, or were there repeat visits for missing parts?
• Were any modifications to the existing exhaust, supports or canopy needed that were not in the original quote?

The last question is important. Unplanned scope is the most common source of RECD cost overruns. If several references describe surprise modifications, expect the same at your site and ask for a site survey before price is finalised.

Theme 2: Performance After Commissioning

• Has visible smoke reduced, and has it stayed reduced?
• Has the generator shown any change in behaviour: harder starting, power drop under load, higher exhaust temperature, alarms?
• Has backpressure ever been measured since commissioning? What was the value?

Backpressure is the single most important engine-side number. If a reference has never had it measured, that is a gap in the vendor’s service model. Our article on how exhaust backpressure affects a DG set explains why this matters for engine health and warranty.

Theme 3: Maintenance Reality

• What maintenance has the device needed so far, and who did it?
• How often is cleaning or regeneration required at your running hours?
• Did the vendor explain this clearly before purchase, or did you learn it later?

Compare the answer with what the vendor told you in its proposal. If the proposal says “minimal maintenance” and the reference describes quarterly cleaning, the difference is not necessarily bad, but you now know which version to budget for. We have unpacked this exact gap in what a “maintenance-free” RECD claim actually means.

Theme 4: Service Responsiveness

• Have you raised a complaint or service call? How long did it take for someone to respond and to arrive?
• Did the issue get fixed on the first visit?
• Do you have a named contact at the vendor today?

Theme 5: Compliance Support

• Did the vendor provide the documents you needed for your pollution control board or for GRAP-period operation?
• Has the installation been inspected by an authority, and were there any observations?

If you operate in Delhi NCR, this theme is especially relevant. The documentation trail matters as much as the hardware when an inspector visits; our guide on what happens during a pollution control board inspection shows what inspectors typically ask for.

Closing Question

End every reference call with one open question: “Knowing what you know now, would you buy from them again, and what would you do differently?” The second half of that question often produces the most useful information of the entire conversation.

Gate 3: Inspecting the Reference Site in Person

A site visit takes half a day. It is worth it for any purchase large enough to need a formal approval. Ask the vendor to arrange access, but request that the visit happens when the generator can be run, even briefly. A device viewed cold tells you about fabrication. A device viewed under load tells you about the system.

Bring your own maintenance supervisor if possible. They will notice things a procurement or admin person will not.

What to Look at: The Physical Checklist

Walk the exhaust path from the engine outlet to the stack exit. Look for evidence rather than impressions.

• Nameplate and identification. Is the device tagged with model, serial number and manufacturer details? Does the model match a certified model on the vendor’s approval documents? Our guide on verifying a CPCB-tested RECD on a DG set lists what should be visible.
• Supports and mounting. Is the device carried by its own structure, or is it hanging off the engine manifold or turbocharger? Load on the turbo outlet is a classic fitment fault.
• Flexible connection. Is there a bellows between the engine and the rigid exhaust? Is it straight, or has it been forced into an offset?
• Welds and flanges. Look for soot streaks at joints. Black streaks around a flange mean exhaust is leaking before it reaches the device.
• Insulation and heat protection. Are hot surfaces lagged or guarded where people walk? Is there scorching on nearby cables or walls?
• Access for maintenance. Can someone reach the service points without dismantling ducting or climbing on the canopy? See our article on service clearance around an RECD for what good access looks like.
• Sampling port. Is there a usable port for stack monitoring, and can it be reached safely?
• Rain and condensate protection. Is the stack capped or designed to keep rain out? Is there any rust trail below the device?
• Instrumentation. Is there a backpressure gauge or tapping point? Is it readable and working?

What to Watch While the Generator Runs

• At start-up: a short puff is normal. Persistent smoke at the stack after the first minute is not.
• Under load: the stack should remain visibly clean. Ask the site operator to apply whatever load is safely available.
• Engine behaviour: listen for hunting, look at the exhaust temperature reading if the controller shows it, and ask whether alarms have appeared since the device was fitted.
• Backpressure reading: if a gauge exists, note the value and compare it with the engine manufacturer’s limit.

Records to Ask for On Site

Ask the facility to show (not hand over) the RECD-related records they hold: the commissioning report, the service log, any backpressure readings and any inspection notes. You are not auditing them. You are checking that the vendor creates documents and the site has received them. A vendor that leaves a clean paper trail at reference sites will likely leave one at yours.

How to Score a Reference Installation

Impressions fade quickly, and different evaluators remember different things. A simple scoring sheet keeps the comparison honest, especially when two or three vendors are being evaluated in parallel. Use a 1 to 5 scale and weight the factors to match your priorities.

Evaluation factor	Suggested weight	What a score of 5 looks like
Relevance to your generator and duty	20%	Same engine family, similar load and running hours
Time in service	10%	Over 12 months including a heavy-use season
Visible performance under load	15%	Clean stack after warm-up, no engine complaints
Fitment quality	15%	Independent support, correct bellows, no leaks, good welds
Maintenance access and safety	10%	Service points reachable without dismantling
Measured backpressure evidence	10%	Recorded readings within engine limits
Service responsiveness reported by owner	10%	Fast response, first-visit fixes, named contact
Documentation provided to owner	10%	Commissioning report, manuals, compliance papers on file

A vendor scoring below 3 on fitment quality or backpressure evidence deserves a second look regardless of its total. Those two factors protect your engine.

Combining Reference Scores With Other Evaluation Inputs

The reference score is one input, not the whole decision. Most organisations combine it with a technical compliance check against their specification, a commercial comparison and a review of certifications. If you are still building your vendor shortlist, our guide on how to choose between CPCB-approved RECD vendors covers the wider evaluation. For tender-based buying, set out the reference requirement explicitly in the tender, as discussed in writing RECD tender specifications with measurable performance requirements.

Reading a Reference That Does Not Match Your Site

Perfect matches are rare. What matters is whether the difference affects the risks you care about.

When the Reference Engine Is Smaller or Larger

A vendor that has fitted a 125 kVA set well has demonstrated workmanship, but not necessarily the structural and lifting planning needed for a 1000 kVA rooftop installation. For larger sets, the questions shift toward structural support, lifting method and thermal expansion. Ask for at least one reference within the same broad size class.

When the Reference Runs Under Easier Conditions

A device in an air-conditioned commercial plant room has had an easy life compared with one in a foundry yard. If your site is dusty, coastal or very hot, look for a reference that shares that challenge. Our guides on RECD selection in dusty industrial locations and RECD choice in coastal, salt-laden environments explain what tends to go wrong in each case.

When the Reference Is Too New

An installation commissioned two months ago proves the device was fitted. It does not prove the device can live with your load pattern for years. Weigh a young reference lightly unless it is backed by an older one.

When the Reference Barely Runs

Many standby sets in grid-reliable areas run only a few dozen hours a year. Such a reference is fine for checking fitment, but says little about soot loading, cleaning intervals or long-term backpressure. If your set runs daily, this is a real gap. Ask for load logs from the reference, the same way you would review your own; our article on using DG load logs to assess RECD suitability shows what to look for.

Red Flags That Should Pause a Purchase

Some findings justify slowing down, asking for more evidence or moving to another vendor.

• The vendor will not give direct contact with the site operator. It may have a reason, but persistent refusal is a warning.
• Every reference is less than six months old. You would be one of the vendor’s early long-term test cases.
• Reference sites report repeat visits for the same fault. That suggests a design or fitment issue, not bad luck.
• The device on site does not match the certified model or has no identification plate at all.
• The device hangs from the engine without independent support.
• No reference site has ever had backpressure measured.
• References describe the vendor going quiet after the final payment.
• The reference site owner says the vendor’s documents were incomplete when an authority asked for them.

A single red flag is a question. Two or three together are an answer.

How Many References Are Enough?

The right number depends on purchase value and risk.

Purchase situation	Suggested reference effort
Single small standby set, low running hours	Two phone references, one close match
Multiple sets or a critical facility	Two phone references plus one site visit
Large sets (above roughly 500 kVA), rooftop or basement	At least one site visit at a comparable size and layout
Hospital, data centre or continuous-process plant	Site visit plus written confirmation from the reference on service response

For critical facilities, the reference check becomes part of your risk control. Hospitals and data centres have specific concerns around testing windows and redundancy, covered in our guides for hospitals and data centres.

Documenting the Reference Evaluation for Your Procurement File

A reference check that lives only in someone’s memory is useless when an auditor, a new manager or a regulator asks how the vendor was chosen. Write a short reference evaluation record for each vendor. One page per reference is enough.

Include:

• Reference site name, contact name and role, and date of conversation or visit
• Generator details at the reference site and how they compare with yours
• Summary of answers under each of the five themes
• Physical inspection observations, with photographs where the site permits
• Score sheet with weights
• Any red flags and how the vendor responded when asked about them
• Name of the evaluator and anyone who accompanied them

This record also becomes an attachment to your purchase approval. If you are preparing that document next, our companion guide on how to prepare an internal approval note for an RECD purchase shows where the reference evidence fits.

Using Reference Findings in Negotiation

What you learn at reference sites should shape the contract, not just the vendor choice.

• If references describe unplanned exhaust modifications, require a pre-order site survey and a fixed scope.
• If references describe slow service, negotiate written response commitments. See RECD service response commitments buyers should agree upfront.
• If references say operators were never shown how to check the device, specify training clearly in the purchase order. Our guide on how to specify operator training in an RECD purchase order includes sample clauses.
• If references describe a messy final stage, agree a punch list process before installation starts. We cover this in how to close an RECD project punch list before final handover.

Vendors respond well to specific, evidence-based requests. “Your customer in the industrial area told us the bellows had to be replaced after three months, so we want bellows replacement covered under warranty for the first year” is a much stronger position than a general request for “better warranty.”

A Short Worked Example

Consider a manufacturing unit with two 320 kVA turbocharged sets that run four to six hours a day in winter, located in an open yard with significant road dust.

The vendor’s list includes 14 installations. Desk screening removes nine: four are below 125 kVA, three are commercial basements with low running hours, and two were commissioned in the last three months. Of the remaining five, the buyer picks two: a 380 kVA set at a plastics unit in service for 18 months, and a 320 kVA set at a warehouse in service for 11 months.

The phone calls go well, but the plastics unit mentions that the first cleaning was needed earlier than the vendor said. The site visit to the plastics unit shows clean fitment, independent supports and a working backpressure gauge, but the sampling port is only reachable from a ladder resting on the canopy.

The buyer’s conclusion: workmanship is good, cleaning intervals should be budgeted more conservatively than the proposal suggests, and the purchase order must specify a safely accessible sampling point. The vendor is retained on the shortlist, with three specific contract changes. That is what a good reference evaluation produces: not just a yes or no, but a better contract.

Frequently Asked Questions

Can I rely on a video or photographs instead of a site visit?

Photos and video are useful for screening, but they are curated. They rarely show supports, flange joints or access constraints clearly, and they never show what the stack looks like under load on an ordinary day. Use them for Gate 1, not as a replacement for Gate 3 on significant purchases.

Is it acceptable for the vendor’s representative to join the site visit?

Yes, and it is often necessary for access. But ask for a few minutes alone with the site operator during or after the visit. Most vendors understand this request.

What if the vendor is new and has very few references?

A new vendor can still be a sound choice if its device is properly certified and its team has relevant experience. Compensate with stronger contract protections: longer warranty, retention money, a detailed acceptance test and clearly written service commitments.

Should references come from my own city?

Local references are valuable because they demonstrate service reach in your area. A vendor with excellent references in another region but none near you should explain how it will service your site. Ask where its nearest service engineer is based.

How do I check whether a reference device is a certified model?

Compare the model and family details on the device plate with the vendor’s type approval documents. Our guide on verifying a CPCB-tested RECD explains the cross-check, and you can review a manufacturer’s published approvals on its certifications page.

Does a good reference guarantee my installation will go well?

No. It reduces uncertainty. Your own installation still depends on an accurate site survey, a clear specification and disciplined commissioning. The reference check simply makes sure you are starting with a vendor that has done this well before.

Final Thoughts

A reference installation is the closest thing a buyer has to a test drive. Used properly, it shows you how a vendor’s promises survive contact with real generators, real operators and real weather. Screen references for relevance, speak to the people who live with the device, stand in front of it while it runs, score what you see, and carry what you learn into the contract.

If you would like to see Aceget installations on generators similar to yours, or need help structuring a reference evaluation for your shortlist, contact our team or explore our retrofit emission control device range.