Using the TM-21 Calculator Tool to Calculate LED Lumen Maintenance

Using

Apr 21, 2019

How do you use the TM-21 calculator tool to calculate LED lumen maintenance at 25,000 hours, 15,000 hours, or 10,000 hours?

To streamline the review process as much as possible, LED Lighting Facts requires partners claiming the optional LED luminaire or replacement lamp lumen maintenance metric to use the Energy Star program’s TM-21 calculator tool, which was developed in cooperation with the National Institute of Standards and Technology. LED Lighting Facts will verify that information from the product’s In-Situ Temperature Measurement Test (ISTMT) report and the LM-80 report for the LED light sources used in the product has been entered correctly, and that the submitted claim matches the calculator’s results.

Instructions are included in the tool, but it is important to know how to use it to calculate LED lumen maintenance at 25,000 hours, 15,000 hours, or 10,000 hours. The necessary fields for each section of the tool’s “TM-21 Calculator” tab are listed below. All section titles reference the blank tool.

1. “LM-80 Testing Details” section

a) Total number of samples tested
b) Number of failures
c) Number of samples measured
d) Test duration (hrs)
e) Tested drive current
f) Tested case temperature 1
g) Tested case temperature 2*
h) Tested case temperature 3*

2. “Tested Case Temperature 1” section

a) Time (hrs) and Lumen Maintenance (%) for the average of each set of measurements at the given time in the LM-80 report.
i. If more than 20 measurements were taken, enter the last measurement from the LM-80 report in row 20 for the Meas. column and work backwards.
ii. Be sure to enter Lumen Maintenance (%) values as percentages. Entering 1 for 100% will result in a miscalculation.

b) Repeat for each case temperature entered in the “LM-80 Testing Details” section.

3. “In-Situ Test Inputs” section

a) Enter drive current for each LED package/array/module (mA)
b) Enter in-situ case temperature

4. “Results” section

a) Enter time (t) to estimate lumen maintenance (hrs). This must be the same as the time selected in the submission form.

Once all of the above information is entered, the value in the cell for Lumen maintenance at time (t) (%) is the LED lumen maintenance percentage. Like other LED Lighting Facts optional metrics, there will be no tolerance on the LED lumen maintenance percentage claim; the claim must be entered to the hundredths decimal place as indicated in the TM-21 Calculator.

Save the file, using the model number being submitted to LED Lighting Facts in the filename, before uploading with other supporting documentation.
Photo source: Energy Star; www.energystar.gov/sites/default/files/asset/document/ESPPM_ENERGY STAR Lighting Update_Jantz-Sell.pdf 

* LED Lighting Facts encourages partners to supply as much performance data as possible. Tested case temperatures 2 & 3 are optional; however, submitting at least two case temperatures is highly recommended. If data from only one LM-80 tested case temperature is entered and the product’s tested case temperature is higher, a partner may not claim LED lumen maintenance. If the product’s tested case temperature is lower than the LM-80 tested case temperature, Tested case temperature 1 data will be used.

Related Articles


Latest Articles

  • Canadian Construction Trends and Opportunities to Watch for in 2025: Procore 

    Canadian Construction Trends and Opportunities to Watch for in 2025: Procore 

    February 24, 2025 By Nolan Frazier, Regional Sales Director, Canada at Procore It’s a new year – and as construction organizations navigate issues such as the skills gap, efficiency, sustainability, and more, it’s a great time to have a look ahead at some of the trends and areas we see affecting the industry in 2025…. Read More…

  • Limited Time Funding in Alberta for EV Charging Installations

    Limited Time Funding in Alberta for EV Charging Installations

    February 24, 2025 Funded by Natural Resources Canada (NRCan) and Alberta Municipalities, the Electric Vehicle Charging Program (EVCP) provides funding for the purchase and installation of EV charging stations in Alberta.  Eligible applicants include businesses, condominium corporations, multi-unit residential building operators, cooperatives, Indigenous communities, industry associations, institutions and schools, municipalities, non-profit organizations, and other, on… Read More…

  • TSBC Information Bulletin: Regulatory Audits

    TSBC Information Bulletin: Regulatory Audits

    February 21, 2025 This information bulletin explains regulatory audits as an inspection practice at Technical Safety BC, including who can be audited, the audit process, and the potential consequences of non-complianc legislative requirements. This bulletin applies to the following technologies: amusement devices, boilers, pressure vessels an refrigeration, electrical, elevating devices, gas, and passenger ropeways. For… Read More…

  • EFC Update on Proposed Tariffs on Steel and Aluminum

    EFC Update on Proposed Tariffs on Steel and Aluminum

    February 21, 2025 An update on proposed tariffs on steel and aluminum can be found below. NEMA has provided this information to their members as well. If the US government proceeds with these plans, the tariffs are scheduled to take effect on March 12, 2025. View the White House Fact Sheet and the Presidential Proclamations adjusting Section 232 tariffs… Read More…


Changing Scene

  • CIB Announces Partnership with JOLT to Expand its EV Charging Network

    CIB Announces Partnership with JOLT to Expand its EV Charging Network

    February 24, 2025 The Canada Infrastructure Bank (CIB) and JOLT have announced a $194 million loan agreement to enable the expansion of JOLT’s electric vehicle (EV) charging network across Canada. The CIB investment will facilitate the installation of up to 1,500 new curbside EV chargers in urban centres, ensuring Canadians have access to convenient charging options. JOLT’s EV… Read More…

  • BC 2025 Minimum Wage Increases by 45 cents in June

    BC 2025 Minimum Wage Increases by 45 cents in June

    February 24, 2025 B.C.’s lowest-paid workers will see a 2.6% wage increase on June 1, 2025, keeping pace with inflation. The general minimum wage increases from $17.40 to $17.85 per hour. This follows the changes made in spring 2024 to the Employment Standards Act, which mandated annual wage increases. “Minimum wage earners are vulnerable to… Read More…

  • Saskatchewan Reverts to Tier 1 on Building Energy Efficiency to Make New Homes more Affordable

    Saskatchewan Reverts to Tier 1 on Building Energy Efficiency to Make New Homes more Affordable

    February 24, 2025 Shifting national priorities, increasing prices and a renewed focus on local industry means the province of Saskatchewan will revert to Tier 1 on building energy efficiency, effective with approval of regulatory amendments. It is anticipated that builders may adopt Tier 1 immediately. “All provinces are dealing with the challenges of growth, including… Read More…

  • BC Construction Industry Echoes Throne Speech Commitments Towards Infrastructure and Housing

    BC Construction Industry Echoes Throne Speech Commitments Towards Infrastructure and Housing

    February 24, 2025 With tariff threats looming, the construction sector has spent weeks preparing for potential instability and turmoil that will upend everyday life for most British Columbians in some way or shape. The BC Construction Association (BCCA) is hopeful that this throne speech demonstrates a strong commitment from the BC Government to implement measures… Read More…