The Collaborative Labeling and Appliance Standards Program (CLASP) – the primary resource and voice for appliance, lighting and equipment energy efficiency worldwide – initiated a study to collect field data on background lighting levels during television viewing. Data was collected from sixty residences over a 7-day time period in October 2011 in both the Washington, DC and Sacramento, CA metro areas.

This study acts on the recommendation of a previous CLASP-funded study, “Analysis of Television Luminance and Power Consumption,” (Jones, 2011) to collect data on actual background lighting levels during television viewing and support the improvement of the television test procedures used by the U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA). The results of this study will assist domestic and international energy efficiency initiatives to develop a television test procedure that measures the energy consumption associated with the automatic brightness control (ABC) feature in a manner more representative of expected consumer usage.

CLASP worked in partnership and collaboration with the California Lighting Technology Center (CLTC) to develop a test plan for collecting data. CLASP engaged Shugoll Research to identify homes and develop screening criteria. Shugoll coordinated installation and removal of equipment with CLTC entering the homes and physically installing and removing the equipment. Keith Jones, from Digital CEnergy Australia, joined CLASP and CLTC to analyze data and identify key findings and conclusions.

Key findings of this study are summarized below: 

1. Typical daytime room illuminance levels can be characterized by three illuminance profiles;
2. Typical nighttime room illuminance levels can be categorized by two illuminance profiles; 
3. An insignificant amount of television viewing occurs at 0 Lux; 
4. The majority of television viewing occurs between  0 and 100 Lux; and
5. The consistency between results for the majority of houses sampled suggests that the results may be representative of houses in the Northeastern and Northwestern regions of the United States.

Key conclusions and recommendations of this study are summarized below:

1. The 0 Lux and 300 Lux test points specified in the ENERGY STAR test procedure should not be used to measure television energy consumption with the ABC feature enabled;
2. Three test points should be used to measure television energy consumption: these three points should be between 10 Lux and 100 Lux; 
3. Further analysis is needed to determine if differences in the amount of time televisions are viewed during the daytime verses the nighttime has a material impact on television energy consumption; and 
4. Additional data collection is recommended, including data collection in regions outside of the United States.

This study is part of CLASP’s larger effort to support energy efficiency testing and compliance initiatives worldwide by providing technical assistance for the development and revision of test procedures; helping to establish and improve test facilities; supporting the improvement of testing practices and compliance; and supporting the harmonization of test procedures regionally or globally.