Can You Install an RECD on a Rented Diesel Generator?

A contractor in Ghaziabad hires a 250 kVA diesel generator for a fourteen-month building project. In month three, an inspector visits the site, looks at the set and asks a simple question: “Is this generator compliant?” The site engineer says it belongs to the rental company. The inspector replies that it is running on his site.

Both statements are true, and neither one answers the question. If you hire diesel generators, you will meet this situation at some point. It leads to a very practical query: could you fit a retrofit emission control device (RECD) on the rented set yourself, and would that solve it?

This guide answers that query in a structured way. It shows how the right answer changes with the length of your hire, who really owns the problem, what the technical obstacles are, what should be in the contract if you still decide to go ahead, and which alternatives are usually smarter.

The short answer

In most cases, no: you should not fit an RECD on a rented generator that belongs to someone else. The better route is to hire a set that is already compliant, meaning one that has an approved RECD fitted or was built to current emission norms, and to ask for the paperwork that proves it. Fitting an RECD on a rented set only starts to make sense for long hires, and only with the owner’s written consent, a clear cost and ownership arrangement, and a plan for what happens when the hire ends. Everything below explains why and how to handle the exceptions.

Turn the dial: how rental length changes the answer

Think of the length of your hire as a dial with four settings. As you turn it upward, the answer changes.

Setting 1: hours to a few days

This is the world of weddings, corporate events, exhibitions and film shoots. The set arrives on a truck, runs for a day or a week and leaves. Fitting an RECD here makes no sense at all. The fabrication alone takes longer than the hire. Your protection is entirely in the choice of the set, and our articles on generator rental for weddings and events and generator rental for film shoots and productions explain how to specify what you need.

Setting 2: weeks to about six months

Short projects, seasonal demand and temporary factory support live here. An RECD is still not a practical option. The installation, commissioning and later removal would consume a large share of the hire period, and you would be paying for a device you would leave behind. The right move is to ask the rental provider for a compliant set from their fleet.

Setting 3: six months to about two years

This is the grey zone. Construction projects, plant shutdown periods and temporary power for expansion often fall here. A retrofit can be justified if a compliant set is not available or costs much more, but the economics are tight, and the contract needs care. Everything in the sections on cost sharing and contract terms below applies to this setting.

Setting 4: multi-year hire or hire with a purchase option

When a hire runs for several years, or is structured as a lease with an option to buy, the set starts to behave like your own equipment. Retrofitting is a normal decision here, and the natural questions are who pays, who owns the device at the end and how the set is maintained. Our comparison of generator rental versus purchase helps you check whether buying outright is now the smarter path.

Rental length	Fit an RECD yourself?	Better move
Days	No	Specify a compliant set in the enquiry
Weeks to about 6 months	No	Ask the provider for a fleet set that is already compliant
About 6 months to 2 years	Only if no compliant set is available, and only by agreement	Negotiate a compliant set, or a cost-shared retrofit
Multi-year or hire-purchase	Often reasonable	Structure the retrofit into the lease or buy the set

Three chairs: who actually owns the problem

Imagine a table with three chairs. In the first sits the rental company, which owns the set. In the second sits you, the hirer, who runs it. In the third sits the regulator, or the inspector acting for it, who sees the set at your location.

The rental company owns the asset, controls its history and usually holds the manufacturer’s warranty. You control how the set is used, where it runs and when. The regulator looks at what is running at your address.

The regulatory framework for diesel generators in the National Capital Region, for example, is written around the DG sets that are in use. The PIB release on CAQM’s revised schedule applies to all sectors, including industrial, commercial, residential and office establishments, and describes requirements by the capacity of each set. It also says State Pollution Control Boards monitor compliance through consent mechanisms and periodic inspections. Another PIB summary of regulated DG operations in NCR sets out which capacities may run and under what conditions, including dual fuel or emission control requirements for defined ranges.

We could not find a public rule that assigns the RECD responsibility specifically to the rental company or specifically to the hirer. That leaves two practical conclusions.

1. Do not assume that “it is rented” protects you. The set runs at your site, and your consent, your premises and your operations are what the authority sees. Non-compliance can lead to consequences described in our article on penalties for running a non-compliant DG set.
2. Settle responsibility in the agreement. State in writing that the provider supplies a set that complies with the regulations applicable at your site on the start date, and say what happens if the rules change during the hire. If a dispute about the legal position arises, take advice from a lawyer, and confirm the regulatory view with your pollution control board or consultant.

Why a rented set is a difficult candidate technically

Even with the owner’s blessing, several technical facts make retrofitting a rented generator harder than retrofitting your own.

The history is unknown to you. An RECD is sensitive to how the engine behaves, including oil consumption, smoke and exhaust temperature. On a set you own, you know its maintenance record. On a rented set, you may not. A tired engine can clog a new device quickly, which then draws blame from everyone.

Rental sets move between sites. A device sized for one engine and one exhaust layout stays with that engine. When the set returns to the fleet and goes to another customer, the RECD goes with it, which may or may not suit that next user. Our guide on whether an RECD can be transferred to another diesel generator explains the five things that must match if a device ever moves.

Rental designs are compact. Many hire sets are compact, soundproofed and built to be trucked around. Space around the exhaust is tight and back pressure margins can be modest. See our comparison of open frame and enclosed canopy generators and our explainer on portable versus fixed installation generators for how these designs differ. Adding an RECD to a compact canopy may need modifications that the owner will not accept.

The engine may not be yours to modify. Manufacturer warranties, such as the terms published on Kirloskar’s warranty service page, typically exclude damage linked to unauthorised modifications or improper installation. Since the warranty belongs to the rental company’s asset, they will be cautious about any change. Our article on whether an RECD affects your generator’s OEM warranty explains the mechanism.

Removal leaves a mark. At the end of the hire, the set has to be returned in its original condition, or agreed condition. That can mean removing the device, restoring the exhaust arrangement and repairing mounting points, all of which cost money and time.

The better route: hire a compliant set

Given all this, the most sensible approach is usually to make compliance the rental provider’s job. Here is how.

Specify compliance in the enquiry

Say in your request that the set must meet the emission requirements applicable at your site, and that you need an approved RECD fitted or a set built to current norms, with documents. Ask for the set’s capacity, engine make and model, and year of manufacture.

Ask for the paperwork

A provider who offers a compliant set should be able to give you the type approval certificate for the RECD, the test report and details of the installation. Match the device plate to the certificate, as explained in our guide on how to verify a CPCB-tested RECD. If the set carries an emission compliance label from the manufacturer, ask for its details too.

Expect a rate difference, and compare it properly

A compliant set may cost more per day or per month than a non-compliant one. Do not treat that premium as a nuisance. Compare it with the cost and risk of the alternative. Our article on diesel generator rental cost in India explains what drives quotes, and our rental tips for India give general vendor-vetting advice.

Ask about rule changes during the hire

Rules and seasonal restrictions can change. Ask what happens if a set becomes ineligible during your hire, whether the provider will swap it and how quickly. For an idea of how restrictions escalate in Delhi NCR, see our guides on GRAP rules for DG sets, what changes at each GRAP stage and how GRAP restrictions affect businesses using DG sets.

If you decide to retrofit a rented set anyway

Sometimes there is no compliant set to be had, or the hire is long enough that a retrofit is the logical step. In that case, treat it as a small project with its own agreement. Here is a term sheet you can adapt.

Retrofit terms for rented DG set [serial number]

1. Consent: The owner consents in writing to installation of an RECD of the type and approval described in Annex A.
2. Installer: Installation will be carried out by [vendor], approved by the owner.
3. Cost: [Owner / Hirer / shared in the ratio ___] bears the cost of supply, installation and commissioning.
4. Ownership of the device: [Owner / Hirer] owns the RECD. If the hirer owns it, the hirer may remove it at the end of the hire.
5. Removal and restoration: On removal, the hirer restores the exhaust arrangement to its original condition at [whose] cost.
6. Credit or buy-back: At the end of the hire, the owner will [credit / pay] ___ for the device, if it remains fitted.
7. Warranty: The owner confirms the effect on the engine warranty in writing. The RECD supplier's warranty is described in Annex B.
8. Maintenance: [Party] is responsible for RECD maintenance as per the supplier's schedule, and logs are kept by ___.
9. Engine condition: The owner confirms the engine's maintenance record and a baseline check of oil consumption and back pressure is recorded before installation.
10. Liability: Each party's responsibility for damage arising from the device, from the installation or from a pre-existing engine condition is set out as follows: ___.
11. Downtime: Downtime due to installation is [not counted / counted] as rental time.
12. Early termination: If the hire ends early, unrecovered device cost is settled as follows: ___.
13. Documents: The type approval certificate, installation record and commissioning readings are given to both parties.

A simple break-even test

Compare two routes over the length of your hire.

Route 1: retrofit. Your share of the device and installation cost, plus removal and restoration, minus any credit at the end.

Route 2: compliant set. The monthly premium for a compliant set from the provider, multiplied by the months of your hire.

If Route 1 costs more than Route 2, or costs about the same but adds risk, take the compliant set. For a hire of under a year, Route 2 usually wins comfortably. For hires beyond two years, Route 1, or simply buying a set, can start to make sense.

A checklist for hiring a compliant set

Before you sign, ask the provider:

1. What is the engine make, model, rated power and year of manufacture?
2. Is an RECD fitted, and if so, which model and which approval?
3. Can you show the certificate and the installation record?
4. Was the RECD fitted by the owner or an approved vendor, and when?
5. What is the set’s maintenance history, and who will service it during my hire?
6. What happens if the set is found non-compliant during an inspection?
7. What happens if rules change or a restriction applies during my hire?
8. Who is responsible for penalties arising from the set’s compliance status?
9. What documents will be kept on site for inspectors?
10. If the set fails, how quickly can you replace it with another compliant set?

Our environmental compliance checklist for generator owners lists other documents worth having at hand, and much of it applies to hirers as well.

What to keep on site

If an inspector visits, be ready to show:

• The rental agreement, with the set’s identification details.
• The RECD certificate and installation record, or the manufacturer’s emission label for a set built to current norms.
• Your site’s consent or registration documents for operating a DG set.
• Maintenance and run-hour logs, where you keep them.
• The provider’s contact for urgent replacement.

A folder in the site office, or a shared drive that the site team can open, is enough. The point is that the person who answers the inspector’s question has the answer in hand.

Special cases

Construction sites

Construction projects often hire sets for a year or more, which puts them in the grey zone of Setting 3. Because these sets run long hours in dusty conditions, engine health and exhaust condition matter a great deal. Insist on an inspection at the start, agree on service intervals, and include a replacement clause.

Events and productions

Events and film work sit at Setting 1, where the practical question is which set arrives on the truck. Ask the compliance question when you order, not when the set is in the car park. Noise, fuel and safe placement matter too, and they are covered in the event and production rental guides linked above.

Small portable sets

Small portable sets fall under different treatment in some regulations. The PIB summary of regulated operations mentioned earlier treats sets below 19 kW separately, with restrictions during GRAP periods. If you hire small portable sets, check the current rule for your location and season.

Hospitals and critical facilities

Where power cannot fail, the priority is reliability first and compliance with it. Ask for a set that is compliant and reliable, and make sure the replacement clause guarantees a quick swap. Modifying a critical rented set at short notice is the wrong moment to experiment.

If you are the rental company

Many readers of this article are on the other side of the counter. If you own a fleet, a compliant set is becoming a selling point in regions with active enforcement. A few practical points:

• Standardise. Group your sets by capacity band and exhaust layout so that RECD design can be repeated across similar sets.
• Document each set. Keep the certificate, installation record and readings in the set’s file and a copy in the cab or canopy.
• Label clearly. A durable label that names the RECD model and certificate reference helps inspectors and customers.
• Price the premium openly. Explain to customers why a compliant set costs what it does and what it saves them in risk.
• Match sets to sites. Send compliant sets to jurisdictions that need them and keep older sets for places where they remain permitted, if the rules allow.
• Plan for rotation. Because RECDs are matched to engines, they should stay with their sets, and when a set is sold, the device and its paperwork should go with it.

If you own a fleet and want to plan a retrofit programme, our team can look at your set list, and our article on choosing a CPCB-approved RECD vendor explains what to check in a supplier. Fleet sites with paired or multiple sets should also read why two diesel generators should not share one RECD.

Frequently asked questions

Can I install an RECD on a rented generator?

Only with the owner’s written consent, and usually only for long hires. For short hires, ask for a set that is already compliant. Fitting a device on someone else’s asset raises questions about warranty, ownership, removal and liability that need to be settled in a written agreement.

Who is responsible for emission compliance on a rented DG set?

We found no public rule that assigns it specifically to the rental company or the hirer. The regulations are framed around DG sets in use at a location, and inspectors see the set at your site. Settle the split in the contract, and confirm the regulatory position with your pollution control authority or a professional adviser.

Will an RECD void the rental company’s warranty?

Not automatically, but manufacturers’ warranty terms often exclude damage linked to unauthorised modifications or improper installation, so the owner will want to review it. Read our article on how an RECD interacts with an OEM warranty.

Who owns the RECD if the hirer pays for it?

Whatever the agreement says. Without a clause, the device becomes part of the owner’s asset in practice, because it is fixed to their equipment. Decide in advance whether the hirer can remove it, or whether the owner buys it back or gives credit.

Is it cheaper to retrofit or to hire a compliant set?

For hires of under a year, hiring a compliant set is usually cheaper and simpler. For hires of two years or more, retrofitting, or buying a set, can compete. Use the break-even test above with real quotes.

What if the rental company says the set is compliant but cannot show papers?

Treat that as a warning. Ask for the certificate and installation record, and verify that the plates match. If they are unavailable, ask for another set, or consider whether you can accept the risk.

Can a rented set be moved to my other site during the hire?

Only if the agreement allows it, and only after checking that the set’s compliance status suits the new location, because regional rules differ.

Need power that is compliant from day one?

If you are planning a long hire, comparing rental with purchase, or running a fleet, share your requirements with our team. We can help you assess whether a retrofit, a compliant set or a purchase makes the most sense. Find capacity-specific options on our retrofit emission control device page, and if you need to send engine details for a quick review, our guide on DG nameplate photos for RECD enquiries shows exactly what to include. You can also reach us through the contact page.