1 | Energy Efficiency and Renewable Energy eere.energy.gov 

Television Set On Mode 

Automatic Brightness Control 

Testing: Effect of Room 

Conditions 

February 2013 

Department of Energy 

Energy Efficiency and 

Renewable Energy 
2 

Overview 

• DOE performed on mode testing with Automatic Brightness 

Control (ABC) enabled in 3 different rooms to determine how 

room physical characteristics may impact power consumption 

– DOE explored variation in wall surface, wall color, and room size 

• Room illuminance measured at the ABC sensor while the TV 

displayed the static IEC main menu 

• Ensured dark room conditions (i.e., illuminance < 1.0 lux in 

standby mode ) 

• Displayed dynamic video content 

• Measured power consumption 
3 

Testing Set-up

• DOE tested the IEC Dynamic Broadcast Content for a duration of 

10 minutes at 10, 35, and 50 lux 

– Power consumption of TV ABC tends to be most sensitive to changes in 

illuminance at these values 

• Room illuminance generated using the Distance test set-up as 

described in the SNOPR 

• All testing performed on TV 41

• Illuminance meter accuracy: ±2% ±1 digit 

1

 TV designation corresponds to those described in the Round Robin Test Report. This material can be found in Docket 

#EERE-2010-BT-TP-0026 at regulations.gov. 
4 

Variables 

• TV tested with sensor facing different walls within each room to 

explore impact of wall texture, color and material in the same 

room 

• 3 different wall types resulted in 3 different room configurations 

Room size 

• Small: 

63 ft2 

• Medium: 

92 ft2 

• Large: 

256 ft2 

Wall texture 

• Matte 

• Glossy 

Wall color 

• White 

• Beige 

Wall material 

• Glass 

• Fabric 

• Paint 
5 

Room A (Small) 

• Room dimensions – 95” x 95”

• Three walls covered in flat white paint 

– Blue in the figures on the next slide 

• One wall covered in beige textured cloth 

– Red in the figures on the next slide 

• Hung a white curtain on the outside of the window allowing the 

window to act as a reflective surface 

• TV tested 3 times, facing different walls 
6 

Room A: Position 1 

Figure not to scale 

Room A 

TV Position 1 
7 

Room A: Position 2 

Figure not to scale 

Room A 

TV Position 2 
8 

Room A: Position 3 

Room A 

TV Position 3 

Figure not to scale 
9 

Room B (Medium) 

• Room dimensions – 107’’ x 112’’ x 102’’ x 149’’

– Trapezoidal 

• Three walls covered in flat white paint 

– Blue in the figures on the next slide 

• One wall covered in beige textured cloth 

– Red in the figures on the next slide 

• Hung a white curtain on the outside of the window allowing the 

window to act as a reflective surface 

• TV tested 3 times, facing different walls 
10

Room B: Position 1 

Room B 

TV Position 1 

Figure not to scale 
11

Room B: Position 2 

Room B 

TV Position 2 

Figure not to scale 
12

Room B: Position 3 

Room B 

TV Position 3 

Figure not to scale 
13

Room C (Large) 

• Room dimensions – 192’’ x 192’’

• All walls covered in black felt 

• Room has no windows 

• Illuminance measured with TV facing only one direction 
14

Room C 

Figure not to scale 
15

Results 

0

20

40

60

80

100

120

140

10 35 50

Average Power (Watts)

Illuminance Value (Lux)

Room Condition Comparison

Room A - Position1

Room A - Position 2

Room A - Position 3

Room B - Position 1

Room B - Position 2

Room B - Position 3

Room C
16

Results 

Power Consumption by TV Location (watts) 

 

Room 

A-1 

Room 

A-2 

Room 

A-3 

Room 

B-1 

Room 

B-2 

Room 

B-3 

Room 

C COV 

Illuminance 

(Lux) 

10 71.6 71.1 70.1 69.3 70.9 70.2 69.6 1.2 % 

35 114 113 112 112 111 113 112 0.8 %

50 127 126 127 126 125 126 126 0.6 %

CV = Coefficient of Variation which is the standard deviation divided by the mean