How many lumens in 40 watt fluorescent tube bulb?

Answer 1

There is no fixed relationship between the brightness (lumens / candela) of a light source, and its power consumption (watts). Incandescent bulbs have a low luminous output for their power consumption, Compact Fluorescent Lamps are intermediate, and LED's are the most efficient in today's world.

Answer 2

2000-3200 depending on design for the old T12. You may not realize it but this is a trick question. It even means money in your pocket; here is why.

There are several levels or types of fluorescent bulbs. Many are familiar with the T12, they are the older type about 1.5 inches in diameter. T12s are now being phased out by law because they are less energy efficient. They use about 1 watt to produce 50 Lumens. The newer T8 use 1 watt to produce about 90 Lumens.

Fluorescent bulbs come in various wattage, and efficiencies. The wattage is most often right on the bulb, if you're confused just enter the numbers into your search engine and it should give the details for each variation. The bulb make up changes energy efficiency and so does the ballast or electronics. The older ballast give off noticeable heat, and so some of that electricity does not become light. Improving electronics have less heat loss to make the same amount of light.

The incandescent light for most of us can provide a comparison, we know about how bright an old 100 watt light is, it produces 1750 Lumens or about 17.5 Lumens per watt. So you can see that the old Fluorescent would still be much more energy efficient at 50 to 1. The T8 are even more energy savings at 90 to 1 (better than most CFLs at average of 60 to 1) LEDs depending on the design can range from 50 to 1 to about 120 to 1, but they do get more expensive as efficiency increases.

When considering lighting, don't be fooled by the hype, just look on the description find the Lumens then divide by the watts, it should be 50 or above to be called energy saving. The cost of the bulb is less important than the cost of the energy.

All of this means huge differences in costs to run. As a lighting efficiency expert I think it is easiest to compare the cost to run over a year. This makes thousands, even millions of dollars of difference for companies using a lot of lighting. Even a modest homeowner may save hundreds of dollars a year with a little thoughtfulness on lighting.

Now there is a T5 tube (5/8 inch) just coming on the market that has my favor, one has an efficiency of 1 watt to 186 Lumens! I did calculations on a fellows lighting just to light his garage (24hrs a day) The way he was doing it cost him $1100. The super high efficiency T5 would cost under $50. a year for power.

Energy efficiency means money in your pocket, less CO2, and if most of use take heed, even fewer power companies needed. I keep telling people that this makes a world of difference, and it can be as simple as changing a bulb!

Answer 3

Light from any source (natural or artificial) travels until it is dispersed by the atmosphere. There are cases in which a single candle can be seen from a mile away by a human eye.

A 40-watt bulb might produce around 30 candelas. The amount of light at a distant point is inversely proportional to the square of the distance. So it might be possible to see a 40 watt bulb at 5.48 miles (the square root of 30).

Of course, the light itself "keeps going", although it may take specialized instruments to detect it.

Answer 4

40 Watts! Perhaps a better question would be how many lumens does a 40 watt tubelight emit, versus an 40 watt incandescent.

Answer 5

350 to 700nm

Answer 6

500