|
Interior
Design Firms |
|
Consulting
Engineering |
|
Archtitectural
Firms |
|
Lighting
Services |
|
Facilities
Management, Building Owners |
|
Electrical/Lighting
Distributors and Manufacturer Reps |
|
Electrical
& Lighting Manufacturing |
|
Basic
Industries & Secondary Manufacturing |
|
Electrical
Contracting |
|
Public
Utilises |
|
Government |
|
Association,
Institutions, Mfg & Services n.e.c. |
|
|
Where
are your biggest areas of maintence/repair
expenditures?
|
For
which areas do you perform scheduled preventive
maintenance?
|
|
HVAC
85%
|
|
|
Store
Equipment 55%
|
|
|
Lighting/Relamping
52%
|
|
|
Floor
care 41%
|
|
|
Electrical
41%
|
|
|
General
Cleaning/Janitorial 37%
|
|
|
Landscaping
20%
|
|
|
Roof
19%
|
|
|
Signage
16%
|
|
|
Parking
Lot 15%
|
|
|
|
HVAC
89%
|
|
|
Floor
care 52%
|
|
|
Lighting
46%
|
|
|
Store
Equipment 40%
|
|
|
Parking
Lot 25%
|
|
|
Roof
22%
|
|
|
Signage
15%
|
|
|
|
|
|
|
|
|
|
|
|
| |
Total
exceeds 100% due to multiple responses |
Source
Building Owners and Managers Association International,
(BOMA)
Electric Power Research Institute (EPRI) |
Notes:The
U.S Bureau of Censors surveyed lighting energy
consumption in buildings show 30% to 45% in
1997. |
Luminance
Criteria of IESNA & ANSI
Reduce
Direct Glare
To reduce direct glare from luminaires at normal
veiwing angles: VISUAL COMFORT PROBABILITY (VCP):
80, MINIMUM
Reduce
Indirect Glare
To minimize reflections of the luminaires in the
VDT screen (indirect glare)
|
Viewing
Angle
|
Recommended
Limits
Angle Continous Use of Computer
|
Recommended
Limits
Intermitten Use of Computer
|
|
55°
|
850
cd/m2 /250 FL
|
--
|
|
65°
|
350
cd/m2 /100 FL
|
850
cd/m2 /250 FL
|
|
75°
|
175
cd/m2 /50 FL
|
350
cd/m2 /100 FL
|
|
85°
|
--
|
175
cd/m2 /50 FL
|
|
90°
|
0
|
0
|
| |
|
|
*Measured
across, along and 45°
ANSI Ammerican National Standards Institute
IESNA Illumination Engineering Society of
North America |
|
Reduce Contrast
To reduce contrast between the VDT screen and
the surrounding area and task: ILLUMINACE: 300-500
LUX (30-50 FOOT-CANDLES), OF AMBIENT LIGHTING.
If a higher level is required because of older
eyes or very demanding tasks, it should be provided
by supplemental task lighting.
Proper
Luminance Ratios
Not more than 3:1 between the task and adjacent
surfaces; not more than 10:1 between the task
and remote surfaces.
|
|
Improved
|
Conventional
|
|
Lamping
|
2-Lamp
T8
|
3-Lamp
T8
|
|
Efficiency
|
70%
|
67%
|
|
Spacing
Ratio
|
1.8
|
1.5
|
|
Candelas
at Nadir
At 8 X 10 Spacing:
|
1437
cd
|
2949
cd
|
|
Illuminance
|
50
fc
|
71
fc
|
| Power
Density |
0.8
W/Sq.FL |
1.1
W/Sq.FL |
Luminance
Ratio
Vertical Task/VDT |
2.1:1 |
3.4:1 |
| Horizontal
Task/VDT |
1.9:1 |
3.6:1 |
| |
|
| The
2 lamp VP paraboic luminaire performs better
than industry standard 3 lamp paraboic troffers
for VDT applications. When laid out properly
the VP meets the Preferred (continuous use)
luminance criteria of ANSVIES RP-1-1993 and
provides 33% savings on lighting costs. |
|
|
