Why this guide exists (and who wrote it)
We are a lighting manufacturer. We have been designing and building LED fixtures in Schaumburg, Illinois since 2002. So yes, we have an obvious interest in this topic. But we also know that the fastest way to lose a customer is to sell them the wrong fixture, have the warranty claim take six weeks, or watch them lose a rebate because the product was not actually DLC listed. This guide teaches you how to verify the things that matter before you commit to any manufacturer, including us. Every claim in here is independently checkable.
The first question: manufacturer or assembler?
Not every company that sells LED fixtures makes them. The commercial lighting market has two types of companies, and the distinction matters for long-term reliability.
| Characteristic | Manufacturer | Assembler / Reseller |
|---|---|---|
| Designs the optical, thermal, and electrical system | Yes. Controls the engineering from LED module selection through housing design. | No. Purchases pre-designed modules, drivers, and housings from separate suppliers and combines them. |
| Controls quality at the component level | Yes. Can inspect incoming components and reject batches that do not meet specs. | Depends on suppliers. Quality varies by supplier and batch. |
| Can modify or customize products | Yes. Can change optics, wattage, CCT, mounting, and form factor based on project requirements. | Limited. Constrained by what their suppliers offer. |
| Supplies replacement parts years later | Yes. Maintains driver and module inventory for warranty coverage. | Depends on whether the original supplier still makes those components. |
| Has photometric (IES) files based on their own testing | Yes. Submits their own products to accredited labs for LM-79 testing. | May use generic IES files from the module supplier, which may not match the final assembled product. |
| US operations | Often has US-based design, assembly, warehousing, or all three. | May be a small office that imports finished goods from overseas factories with no domestic production. |
How to check: ask the company if they can provide an LM-79 test report for the specific product you are evaluating. An LM-79 report is a photometric test of the complete luminaire, performed by an accredited third-party lab. A manufacturer who designed and tested their product will have this. An assembler who buys finished goods may not.
Certifications: what they mean and how to verify each one
Every manufacturer claims their products are "certified." The question is: certified by whom, for what, and can you verify it independently? Here are the certifications that actually matter for commercial LED fixtures and how to check each one yourself.
| Certification | What it means | How to verify |
|---|---|---|
| UL Listed (UL 1598) | The fixture has been tested by Underwriters Laboratories and meets safety standards for its listed location type (dry, damp, or wet). Required by most building codes. The inspector will check this. | Look up the manufacturer's UL file number at productiq.ulprospector.com. Every UL-listed product has a public file number. |
| ETL Listed | Equivalent to UL. Tested by Intertek to the same UL standards (e.g., UL 1598). Accepted by inspectors and AHJs nationwide. Some manufacturers choose ETL because the certification process is faster. | Look up at intertek.com/directories. Same verification process as UL. |
| DLC Standard | The fixture meets DesignLights Consortium efficiency and performance standards. Required by most utility rebate programs. Must have UL or ETL listing and at least a 5-year warranty. | Search the DLC Qualified Products List at designlights.org/qpl. Search by manufacturer, model, or product category. If the specific model and wattage are not on the QPL, it is not DLC listed. |
| DLC Premium | Higher efficiency tier. Qualifies for larger rebates in many utility programs. Stricter efficacy and performance requirements than DLC Standard. | Same QPL lookup. The listing shows whether the product is Standard or Premium. |
| IP rating (e.g., IP65, IP66) | Ingress Protection: resistance to dust (first digit) and water (second digit). IP65 = dust-tight + water jets. IP66 = dust-tight + powerful water jets. Required for outdoor and wet-location fixtures. | Should be stated on the spec sheet and test report. The IP test is performed to IEC 60529 standards. Ask for the test report if the rating seems unusually high for the fixture type. |
| UL 844 (Hazardous Location) | The fixture is rated for Class I, II, or III hazardous locations (flammable gases, combustible dust, ignitable fibers). Required for gas station fixtures within classified zones, grain elevators, paint booths, etc. | UL file number lookup. The listing specifies the Class, Division, and Group ratings. |
Source: DLC Solid-State Lighting Technical Requirements V5.1 (minimum 5-year warranty, UL/ETL listing required for DLC qualification). UL 1598 is the standard for luminaire safety. All verification databases listed above are free and publicly accessible.
Marketing materials lie. Databases do not. Some manufacturers claim DLC listing on their website or spec sheet for products that are not actually on the QPL. This can happen when a similar model is listed but the specific wattage or CCT configuration is not, or when a listing has been delisted due to a new DLC version. Always verify the exact model number and wattage on the DLC QPL before specifying for a rebate project. If the project loses the rebate because the product was not actually listed, the contractor usually absorbs the loss.
Warranty: the questions the spec sheet does not answer
Every commercial LED manufacturer offers a warranty. The headline number (5-year, 10-year) tells you almost nothing. The actual terms tell you everything. Here is what to ask:
| Question | Why it matters | Red flag answer |
|---|---|---|
| Does the warranty cover the LED driver? | Driver failure is the #1 cause of LED fixture failure. The LEDs themselves rarely fail within their rated life. If the warranty excludes the driver, it excludes the most likely failure mode. | "LEDs are covered for 10 years; driver is covered for 3." |
| Is the warranty prorated or full replacement? | A prorated warranty reduces coverage over time. In year 7 of a 10-year prorated warranty, you may only get 30% of the replacement value. | "Coverage decreases proportionally over the warranty period." |
| Does it cover labor and shipping, or just the part? | If the warranty only covers the replacement fixture and not the shipping or labor to swap it, the real cost of a warranty claim at height (scissor lift + electrician) may exceed the fixture value. | "Warranty covers the replacement unit only. Customer is responsible for shipping and installation." |
| What is the claim-to-replacement turnaround time? | A warranty claim that takes 6 weeks to process leaves the customer with a dark spot for 6 weeks. Ask for the typical turnaround in business days. | "Submit a claim form and we'll get back to you." (No specific timeline.) |
| Is the warranty transferable to the building owner? | In new construction and tenant build-outs, the contractor installs the fixtures but the building owner operates them. If the warranty is not transferable, the owner has no coverage after the contractor moves on. | "Warranty applies to the original purchaser only." |
| What documentation is required to file a claim? | Some manufacturers require the original invoice, proof of installation by a licensed electrician, and a completed registration form. If the contractor did not register the product at installation, the warranty may be void. | "Warranty is only valid if the product is registered within 30 days of purchase." |
Lead times and inventory: the variable that derails projects
A fixture that ships in 8 weeks is a different product than the same fixture that ships in 3 days. Lead time affects project scheduling, staging, and the contractor's ability to close out the job. Here is what to verify:
- Ask for current lead times, not catalog lead times. Published lead times are often best-case estimates. Call the manufacturer or distributor and ask what the lead time is right now, for the specific SKU and quantity you need.
- Distinguish between stocked and made-to-order. A stocked product ships from a domestic warehouse. A made-to-order product is assembled or imported after the order is placed. The difference can be days vs. weeks.
- US-based inventory matters. A manufacturer with domestic warehouse stock can ship within days. A manufacturer who imports from overseas depends on ocean freight schedules (4-6 weeks), customs clearance (1-2 weeks), and last-mile trucking. Any disruption in this chain pushes the lead time out unpredictably.
- Ask about partial shipments. If only 80% of the order is in stock, can the manufacturer ship what is available now and backorder the rest? Or does the entire order wait until everything is available?
Technical support: what to expect from a manufacturer vs. a reseller
The lighting fixtures are the hardware. The technical support is the service layer that determines whether the hardware ends up in the right place, at the right output, meeting the right code requirements. Here is what a real manufacturer should be able to provide:
| Service | What it is | Why it matters |
|---|---|---|
| Photometric layouts | A computer-simulated lighting plan showing fixture placement, foot-candle values, and uniformity ratio for your specific space dimensions. | Prevents over-lighting and under-lighting. Confirms code compliance (LPD, fc targets) before installation. Saves rework. Learn more in the photometric reports guide. |
| IES file availability | The manufacturer provides downloadable IES files for each product so that any independent lighting designer can run their own photometric simulation. | IES files are the raw data that lighting design software (AGi32, DIALux) uses. A manufacturer who does not provide IES files is making it impossible for the designer to verify their claims independently. |
| Spec sheet accuracy | Published wattage, lumen output, efficacy, CCT, CRI, IP rating, dimensions, weight, and certifications match the actual product tested. | Check the spec sheet guide for the specific items to verify. Key red flag: lumens listed are "lamp lumens" (LED chip output) rather than "luminaire lumens" (complete fixture output). The difference can be 10-25%. |
| Application engineering | A technical contact (not a sales rep reading a script) who can answer questions about optics, controls compatibility, mounting options, and code compliance. | On complex projects (NLC integration, hazardous location, custom optics), the difference between a manufacturer with application engineers and a reseller with sales reps is the difference between a project that works and one that needs a change order. |
The 10-point manufacturer verification checklist
Use this checklist before committing to any LED manufacturer for a commercial project. Every item is independently verifiable.
| # | Verification item | How to check |
|---|---|---|
| 1 | UL or ETL listed for the appropriate location rating. | UL Product iQ database or Intertek directory lookup. |
| 2 | DLC Standard or Premium listed (if rebates are part of the project). | DLC QPL search by manufacturer + exact model number + wattage. |
| 3 | LM-79 test report available for the specific product. | Request from the manufacturer. Report should show luminaire lumens, efficacy, CCT, CRI, and the accredited lab name. |
| 4 | IES files available for download. | Check the manufacturer's website or request directly. Every serious manufacturer publishes IES files. |
| 5 | Warranty covers the LED driver, not just the LEDs. | Read the warranty terms document (not the marketing summary). Ask specifically about driver coverage. |
| 6 | Warranty claim turnaround is defined in business days. | Ask the manufacturer for their average claim-to-ship time. Get a specific number. |
| 7 | US-based inventory with current lead time under 2 weeks. | Call and ask for the current lead time on the specific SKU and quantity. Not catalog lead time. Current. |
| 8 | Photometric layout service available. | Ask whether they provide complimentary photometric layouts and what information they need from you. |
| 9 | Spec sheet lists luminaire lumens (not lamp lumens) and includes all relevant certifications. | Compare the lumen value on the spec sheet to the LM-79 report. They should match. See the spec sheet guide. |
| 10 | Application engineering support available (not just a sales team). | Call with a technical question. A manufacturer with application engineers will give a specific, useful answer. |
Frequently asked questions
What certifications should commercial LED fixtures have?
At minimum: UL or ETL listed for the appropriate location (dry, damp, wet), and DLC Standard or Premium if the project needs utility rebates. UL/ETL covers safety (tested to UL 1598). DLC covers performance and efficiency (tested via LM-79). Both are independently verifiable on public databases. Additional certifications (IP rating, IK rating, UL 844 for hazardous locations) apply to specific applications.
How do I verify a DLC listing?
Search the DLC Qualified Products List at designlights.org/qpl by manufacturer name and model number. The QPL shows tested wattage, lumens, efficacy, CRI, CCT, and listing date. If the exact model and wattage configuration is not on the QPL, it is not DLC listed, and the project will not qualify for rebates. Marketing materials are not verification. The QPL is.
What should I look for in a warranty?
Read beyond the headline number. Key items: Does it cover the LED driver (the most common failure point)? Is it full replacement or prorated? Does it cover shipping? What is the claim-to-replacement turnaround in business days? Is it transferable to the building owner? What documentation is required? A 10-year warranty with a 6-week turnaround and a registration requirement nobody mentioned is worse than a 5-year warranty with next-day shipping.
What is the difference between a manufacturer and an assembler?
A manufacturer designs the optical, thermal, and electrical systems and controls production. An assembler purchases pre-made components and combines them. The practical difference: a manufacturer can customize designs, provide LM-79 reports for their own products, control quality at the component level, and supply replacement parts years later. An assembler depends on their suppliers for all of these things.
Why does US-based manufacturing matter?
Three reasons: lead times (days vs. weeks), warranty support (domestic claim processing and replacement shipping), and quality control (direct oversight of production catches issues before products ship). A manufacturer with US operations can respond faster to both orders and problems than an import-only company depending on overseas production and container shipping.
How do I evaluate pricing fairly?
Compare the total cost of ownership, not just the fixture price. The fixture cost is typically 20-30% of the total project cost. Installation labor, wiring, controls, rebates, energy savings, and maintenance over the fixture's life are the other 70-80%. A fixture that costs 15% more but qualifies for a larger rebate, ships faster (reducing labor staging delays), and has a driver warranty that prevents a callback in year 4 is cheaper in total than the lower-priced alternative.
