The introduction of TM-30 in 2015, and the addition of Annex E in 2018, marked a huge step forward in characterizing the suitability and desirability of different LED light sources for a wide range of lighting applications. And yet, the adoption of TM-30 and the associated Annex E designations is not as universal among lighting manufacturers as one might hope. Some of this delay may be due to the lack of information, which may be attributed to the difficulties and challenges that face luminaire manufacturers.
There are three main challenges that manufacturers face when offering TM-30 data to customers: wide product line variations; constraints on product testing; and frequent LED source changes for product improvements.
Many LED lighting manufacturers have a product catalog that offers a wide range of CCTs and CRIs as part of their offering. Moreover, depending on the application, products in the same family may use different LED types for different applications such as a small-footprint Chip Scale Package (CSP) device for narrow beams and a larger and more efficient domed device for wider beams. Combine this with variations in drive current for different lumen packages, and a given product family can have thousands (or tens of thousands) of possible variations. Testing every one of these variations would be onerous in terms of time and expense. Most manufacturers measure data on representative luminaires and then scale data (analogous to lumen scaling of IES files) based on CRI, CCT and power. As such, TM-30 data for a specific product configuration may not be readily available without additional testing.
Another challenge for lighting manufacturers is the trade-off between the capital expense of purchasing a 2-meter integrating sphere and spectrometer for luminaire measurements versus paying an outside certified lab for those measurements. Color testing is typically performed during goniophotometric testing that measures photometric distribution. An integrating sphere and spectrometer combination can cost more than $50,000 and might also require the hiring of a dedicated technician to run it, depending on the number of measurements. Paying an outside lab to do the testing involves lead times that can range from days to weeks, which can cost several hundred dollars per test (plus the cost of the luminaire sample). For a few hundred tests, the total cost can exceed $100,000.
Lastly, manufacturers are commercially motivated to periodically update the performance and decrease the cost of the LEDs used in their products. Moreover, LED manufacturers also update their LEDs to “next generation” versions that have greater performance but can induce changes in photometry and color metrics. As such, a fixture manufacturer’s investment in comprehensive test data—with associated costs potentially in the hundreds of thousands of dollars—is only accurate for the length of time the LED in that luminaire remains unchanged. This may be as short as 12 months.
Recognizing these challenges and constraints, what can specifiers and lighting designers do to facilitate the increased use of TM-30 specifications on projects and minimize the frustration of collecting the data to support those specifications?
One strategy is to communicate to the manufacturer early and often that TM-30 will be required for any submission on a bid or specification. Given the small proportion of data collected compared to the tens or hundreds of thousands of SKUs offered by the manufacturer and the lead time associated with building a specific luminaire and collecting that test data, asking for TM-30 with short notice is destined to be frustrating and likely disappointing for everyone involved. Providing advanced notification that submissions require TM-30 data (or that any luminaire submitted for a particular line on the schedule requires a P1F1 rating, for instance) provides luminaire manufacturers time to evaluate the suitability of their offerings to hit such targets, and sufficient time to build samples and test them. This is especially important if third party testing is required.
Another strategy would be acceptance of TM-30 data for a representative SKU rather than the specific SKU specified. For example, Manufacturer A has data for a linear product with 750 lumens per ft at 3000K/95 CRI that achieves a P1F1 rating, but the desired SKU is a similar version at 500 lumens per ft. A specifier could request the “nearest available SKU using product lines as a business approach. Some manufacturers adopt a business strategy to use LEDs from multiple manufacturers and across multiple different footprints to maximize efficacy, choice and cost effectiveness across product lines. Other manufacturers choose to make the trade-off either in cost, application suitability or efficacy to standardize on a much smaller number of LEDs for their product lines to minimize supply chain complexity and optimize cost. A common example of this is offering a standard option (e.g., “90 CRI”), but limiting LEDs to a single manufacturer, or a limited number of families from a smaller number of manufacturers. The luminaire manufacturers that follow this path may offer fewer mid-life luminaire refreshes over time, but also can be more responsive to TM-30 data requests due to having fewer overall SKUs and lower product churn.
A last editorial note: For a specifier and lighting designer, it is important to request the TM-30 data of the luminaire, as optical components used in luminaire design can affect various colors (or wavelengths) differently which can lead to subtle changes in TM-30 metrics.
While at first blush one might assume that providing TM-30 with every luminaire variation should be a straightforward request to an LED luminaire manufacturer, there can be consequential cost, time and resource constraints in doing so. Choosing luminaire partners who are committed to using TM-30, communicating requirements for data needed for specific designs and specification as early as possible, and being flexible in accepting data from appropriately adjacent product configurations can smooth the path to providing the confidence in outcome that TM-30 data can help deliver.