Are you shopping for new light bulbs? It’s important to know that while watts was once the measure of a bulb’s light, today light is usually measured in lumens. So, what are these things called lumens?
What are Lumens?
That’s a good question—one we’re going to help you answer! According to the Merriam-Webster online dictionary, a lumen is “a unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of one candle intensity.” OK…what does that mean?
In understandable English, lumens are equal to the brightness of the light put off by a bulb or another lighting source. This is the measure of the light output of the source, which could be a light bulb. So, the more lumens a bulb has, the brighter it will be.
In the past watts were used. These did not measure the amount of light coming from a source, but rather the energy used to produce the light. So, there’s a big difference between lumens and watts.
How to Convert Watts to Lumens?
It is possible to convert watts to lumens, but not vice versa. You can’t convert lumens back into watts because some of the energy will be used to create the light. So, you have to use a ratio between lumens and watts to determine the efficiency of the light bulb.
Here are some examples:
- A 100 W incandescent bulb produces about 1600 lumens for an efficiency of 1600/100=16 lumens per watt.
- A Halogen bulb uses 72 watts to create the same amount of brightness, so the ratio is 1600/72-22 lumens per watt.
- CFL bulbs use 26 watts, so it has an efficiency of 61 lumens per watt.
- LED bulbs use 22 watts and have an efficiency of 73 lumens per watt.
In this example, the LED is the most efficient bulb in the bunch.
What are 2000 Lumens and 3000 Lumens?
These numbers are most significant when you’re considering the type of lighting in a room or when buying a projector. These numbers are the amount of light the lighting or the project will put out.
How to Choose a Projector
You’ll see a big difference between a projector that has 2000 lumens or one that has 3000 lumens. It’s pretty obvious. If your room has light from other sources, then the 3000-lumen light will be best. On the other hand, if the room has lower light, or lights that are controlled, then the lower lumen light will be just fine.
For example, if you have a conference room that has low light, or controlled lighting, then the 2000-lumen projector will be the best choice. Images will be crisp and bright, but not too bright.
A 3000-lumen project is the best option for room that have some natural light. The reason is that you will have to compensate for the brightness of the natural light coming in. So, the higher-lumen projector will be the best option in this case. The image will be visible and crisp, in spite of any natural light entering the room.
It’s good to keep in mind that there’s not much difference between projectors that have 2000 lumens or 2200 lumens. They both present about the same quality image at the same brightness level. In most cases, the 2000 lumen project is the best option for most people.
Choosing Lights for Your Room
In order to determine how much light is needed in a room, you’ll first need to calculate how much light is needed per square foot. So, you’ll need to know the room’s area and then how many footcandles are needed. Foot what? Footcandles is the measurement of how bright a light is when you’re one foot away from the light. OK—that’s weird, but these are necessary measurements to determine how much light will be needed in a room. Let’s take a look at an example.
Say your kitchen, which is an area that needs bright light, is about 100 square feet. For a room of this size you’ll need about 30-40 footcandles (which is about 3000 to 4000 lumens).
This is quite a bit of light, which is appropriate for a kitchen. But this would be too much light for a smaller room, or a room where you’d like the lighting to be more comfortable. For a living room, you may want to go with 2000 lumens (if the room is 200 square feet).
How to Read a Lightbulb Label?
When it comes to reading the new light bulb labels, it’s a bit confusing. This is due to the changes in technology and lighting regulations in recent years. So, now we all have new terms to learn about lighting and how bright the lighting should be in certain rooms, and more.
Thankfully, newer light bulbs have “Lighting Facts” labels, which are a bit like the ingredient labels on food. You won’t find food ingredients on the lighting facts label, however! Instead, you’ll find these facts:
- Brightness: which will include a number of how many lumens the bulb puts off
- Estimated yearly energy cost
- Life of the bulb: based on a specific number of hours/day
- Light appearance: this lets you know the color of the bulb—whether it will be warm or cool
- Energy used: this is the amount of energy the bulb uses
Lumens are a little confusing at first, but once you understand exactly what they are, it’s not too difficult to determine the type of projector or light bulbs you need in a specific room. The key is to remember that the more lumens, the brighter the bulb will be.
And these days, light bulb comes with the lighting facts listed directly on the box! They’re easy to read and understand, and you’ll have all the information needed to choose the best bulb for your room.
You won’t have to use crazy charts, do the conversions yourself, etc. Now you’ll have a good understanding on what lumens are and how to choose the right type of light bulb or projector for any specific room. And you even know what footcandles are! You’ve got this!