1. Compare Performance at the Application Level
Conduct "in field" application level performance evaluations using IESNA recommended practices and standards. Utilize the best available design software and application engineering practices to predict application level performance. Evaluate relevant and credible case studies such as the Department of Energy's CALiPER and GATEWAY programs.

2. Request Certified Photometric Data
Make sure the LED luminaire manufacturer provides a certified photometric report (per IESNA LM-79) from an approved DOE lab to validate the manufacturer's photometric performance claims.

3. Validate Lumen Depreciation
Obtain lumen depreciation (life) data for the LED luminaire supported by the LED chip manufacturer's IESNA LM-80 test data that is directly correlated to luminaire level performance.

4. Apply the Appropriate Light Loss Factors
An accurate application comparison must account for the light levels at the end of the application life. Using the manufacturer's LED luminaire lumen depreciation data, apply the correct light loss factor to the application.
For example, a typical outdoor dusk-to-dawn application may be evaluated at a 50,000 hour (~11 - 12 year) application life. Based on this example, you would conduct an evaluation based on each manufacturer's 50,000 hour lumen depreciation values.

5. Evaluate Lifetime Luminaire Value
Analyze initial investment versus lifetime value by considering all LED fixture benefits such as lighting performance, total power consumption, maintenance and warranty. The entire luminaire must be built to last for the length of the application life.

LED Fixture Comparison Tips