ANOTHER
G & G ELECTRIC AND PLUMBING DISTRIBUTORS, INC.
INFORMATION SHEET
23
COPYRIGHT 1989
HOW TO DETERMINE ADEQUATE LIGHT LEVELS
This
cha rt
was
developed
as
o ur
recom mendat i o n f o r a d e q u a t e l i g h t i n g
l e v e l s u n d e r t h r e e hypothetical decorative
situations: dark, medium and light colored
walls and ceilings.
It is based on the average lumen output
of 60, 75 and 100 watt inside frosted
incandescent light bulbs since these sizes are
most commonly used in fixtures for general
lighting. When smaller wattage bulbs are
used, the w attage requirem ents should be
considered somewhat higher than those
shown in the chart and, likewise, if larger bulbs
are used, the need can be considered
somewhat lower. This is to compensate for
the fa ct that lo w er w a tta g e b ulb s p ro d uce
few er lumens per watt than those of higher
wattage.
We are aware t ha t in d iv id u a l l ig h t le v el
p re fe re n ce s v a r y co n siderably. However,
once the fixtures are installed, it is much
easier and less costly to reduce lighting levels
than to increase them.
N o te tha t when fluorescent l i g h t i n g i s
used in place of incan descent, the
amounts shown in the chart can be reduced
by one-half since fluorescents produce well
over twice as m any lumens per wa tt tha n
incandescent
bulbs. We have included
equivalent lumen output per square foot to aid in
light level calculations using sources other than
standard incandescent.
TO USE THE CHART
1.
2.
3.
Find the square footage of your room by
multiplying its length by its width.
M ultiply this tota l by the wa tts per
square fo ot figure shown in the chart
that corresponds with t h e t y p e o f
room you are figuring and its
decorative scheme.
The answer you get is the desirable amount
of inca nd escent lig ht yo u need . This
to ta l ca n b e rounded up or down so as to
be applicable using standard wattage bulbs.
LIGHT COLORED
DECOR
MEDIUM COLORED
DECOR
DARK COLORED
DECOR
*Kitchen
Ba throom
Den
Study
Wo rkshop
4 Watts
(56 L umens)
per sq. ft.
5 Watts
(70 L umens)
per sq. ft.
6 Watts
(84 L umens)
per sq. ft.
*Bedroom
*L iving Roo m
Den
*F amily Roo m
Utility
3 Watts
(42 L umens)
per sq. ft.
4 Watts
(56 L umens)
per sq. ft.
5 Watts
(70 L umens)
per sq. ft.
TYPE OF ROOM
*D ining Roo m
2- 1/2 Wa tts
2 Watts
*Enterta inm ent Area
(28 L umens)
(35 L umens)
Stora ge Roo m
per sq. ft.
per sq. ft.
Ha llw ays
* Indicates a room where use of a dimmer switch is suggested.
3 Watts
(42 L umens)
per sq. ft.
These “How-To-Do-It” sheets have been reviewed in June 2007 by a professional Engineer. If you find a problem, please notify
G & G Electric & Plumbing at 1900 NE 78th Street, Ste. 101, Vancouver, Washington 98665