Lumens Per Watt Lamping Comparison - Light Bulbs at a Glance

Lumens are a measurement of the perceived power of light. All ratings approximate.
Efcacy = lumens/watts. The higher the number, the more efcient.
Approximate CO2 emission per 1,000 hours of use assuming coal generated electricity.
C02 output per lumen is a fner gauge of sustainability.
CRI = Color Rendering Index. 100 = full color range: incandescent.
CCT = Correlated Color Temperature in degrees Kelvin.

Incandescent

This is the traditional “Edison” light bulb. It emits light in a warm, broad spectrum; however, approximately 90% of all the power consumed by an incandescent light bulb is emitted as heat rather than visible light. Given far more efcient alternatives, some governments are mandating a phase-out or ban of its use.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
25	170	07	33	.194	1000	100	2700
40	495	12	46	.105
60	830	14	78	.093

Pros: ----- cheap; gives a pleasant warm light that most people like,

Cons: ----- least efficient of all the bulbs

Uses: ----- General lighting

Notes: ----- can heat up, therefore care must be taken near flammable material, short life span.

Halogen

Halogen is a form of incandescent. It has the truest color rendering of any light source other than the sun and is therefore often used to illuminate works of art. In the MR16 format, this long-lasting, low-voltage spot is amplifed by an integrated refector, greatly increasing its apparent efcacy.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
20	320	16	26	.081	2000 - 4000	100	2950 - 6000
35	600	17	46	.077
50	900	18	65	.072

Pros: ----- more efficient than incandescent bulbs; bright light

Cons: ----- burns very hot; more expensive than incandescent

Uses: ----- 220v tubes - General lighting, floodlights

12V - ----- accent lighting, task lighting

Notes: ----- must be careful using these bulbs near flammable materials or in closed places.

Fluorescent Tube T5 T8

The “new and improved” ficker-free fuorescent tube ofers good color rendering, long life and low cost. Like all fuorescents, special disposal measures are required due to mercury content.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
T5 ( 28W )	2900	104	31	0.015	25000 + 35000	82 - 85	3000 - 6500
T5 ( 35W )	3450	99	70	.014	25000 + 35000	82 - 85	3000 - 6500
T8 ( 17W )	1260	80	22	.017	20000 - 46000	78 - 96	3000 - 65000
T8 ( 32W )	2800	80	46	.016	20000 - 46000	78 - 96	3000 - 65000

Pros: ----- bulb burns cooler; very efficient; can come in various CRI ratings; comes in different

Cons: ----- not dimmable; fixtures are more costly; known to flicker at times.

Uses: ----- General, floodlights

Notes: ----- frequent switching on and off reduces efficiency.

Compact Fluorescent (CFL)

CFLs use less energy than incandescents and can last up to eight times longer (if not overheated) while generating light that is becoming increasingly comparable. CFLs contain trace amounts of mercury, requiring special disposal measures. The ballast must be discarded along with this type of lamp.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
13	850	65	17	.020	10000	82 - 90	2700 - 4100
18	1100	61	23	.020
23	1600	69	30	.018

CFL non-integrated ballast

These CFLs utilize separate, reusable electronic ballasts; they are slightly more efcient and can last longer compared to integrated-ballast CFLs. One ballast will often run multiple wattages and permit dimming. Lamp disposal issues are the same.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
26	1800	69	34	.019	12000	82 - 90	2700 - 6500
32	2400	75	42	.018
36	2800	78	47	.016

Pros: ----- Efficient

Cons: ----- Cost of bulb; sometimes they can't physically fit; to replace incandescent bulbs.

Uses: ----- General lighting

Notes: ----- Frequent switching on and off reduces efficiency.

Ceramic Metal Halide

Metal Halide is an efcient, high-output lamp commonly used to illuminate large outdoor areas, in part because its output is unafected by environmental temperature changes. Due to high intensity and slow start-up, it is best suited for outdoor and commercial applications. MHs contain mercury, requiring special disposal measures.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
22	1155	53	27	.023	12000	81-96	2900 - 4100
70	4500	64	91	.020
150	9800	65	195	.020

Pros: ----- extremely efficient; give a brilliant light; bulbs come in different color temperatures; good color rendering.

Cons: ----- cost of both fixture and bulb; burns hot

Uses: ----- places where a lot of light is needed such as outdoor areas and retail shops. Used frequently in sports arenas, stadiums, auditoriums, and convention halls

Notes: ----- not to be used near flammable materials. Bulbs usually must burn in a certain position.

High Pressure Sodium (HPS)

These lamps are typically used for streetlights and security lighting, where color rendering is not critical. HPS lamps contain trace amounts of mercury, making disposability an issue, and they decline in lumen output as they age. White“SON” is a higher cost HPS variant with a high CRI but reduced life and efcacy.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
35	2250	64	46	.020	16000	22	1900
70	6400	91	91	.014	16000	22	1900

Pros: ----- extremely efficient, long lasting,

Cons: ----- bad color rendering, produces yellowish light; slowly lose their brightness with time

Uses: ----- very popular for indoor horticulture, outdoor and industrial applications

Notes: ----- Please see note at bottom.

Light Emitting Diodes (LEDs)

LEDs are a promising technology currently undergoing rapid development. Their warmth and color rendering can be comparable to incandescent in certain applications. Their small size makes them highly versatile. Given their long life, high efciency and low toxicity, their cost is likely to be justifed over time.

Energy Watts	Output Lumens	Efficacy Lumens Per Watt	CO2 lbs	CO2 Lumen Ratio	Liff (Hours)	CRI 1-100	CCT Kelvin
4	400	100	04	.015	50000	50 - 95	2700 - 6500
7	700	100	07	.014
9	900	100	09	.013

Pros: ----- High durability - no filament or tube to break; long life span; low power consumption; low heat generation

Cons: ----- High cost of bulb (in the meantime 1-1.5USD/W)

Uses: ----- wide variety of uses including general lighting, accent lighting, and decorative lighting

Notes: ----- LED technology is relatively new, and is changing every day. The quality and efficiency of the bulbs are improving all the time.

Please Note:

If sodium lamps break, ventilate the area where breakage occurred. Clean-up with vacuum cleaner or other suitable means that avoids dust generation. Take usual precautions for collection of broken glass. Clean-up requires special care due to the fact that sodium reacts with the moisture on the skin and in the air. Materials from broken lamps should be treated as for spent lamps. To avoid the risk of sodium reaction when disposing of spent lamps, the following procedure should be followed:

Before commencing, operator should be outfitted with appropriate face mask, gloves and apron.

Place lamps in a dry, high container and break lamp(s) into small pieces in a dry atmosphere and in a well ventilated area.

From a safe distance, pour enough tap water into container to cover all materials.

After a few minutes, the reaction of the sodium with the large quantity of water will produce a mild sodium hydroxide

solution which may be disposed of in accordance with applicable local regulations.

Comparing Efficiency Is Easy

The lumens and wattage will often be given on the packaging or on the bulb itself. To compare bulbs for efficiency, determine the number of lumens the bulb will produce per watt by dividing the lumens by watts. The lower the result, the more efficient the bulb. For example, an 4-Watt, 400-lumen LED bulb produces about 100 lumens per watt (that is 400 divided by 4). A common 40-Watt, 495-lumen incandescent bulb produces only 12 lumens per watt.

giovedì 12 giugno 2014