How to Choose Light Bulbs

Is a Lumen More Important than Wattage?

We've probably all heard of light bulbs described in terms of wattage. Roughly, the more watts a lightbulb consumes, the brighter the bulb, right? While this once may have been an adequate rule of thumb, it's no longer technically accurate.

In modern times, a lumen is a far better measure of your bulb's performance than wattage. So, what is a lumen?

Put simply, a lumen is a unit of measure for "brightness" or how much light your bulb produces. 1 lumen is roughly equivalent to the light produced by a single burning candle. A watt describes how much energy your bulb consumes to output lumens of brightness. Your bulb's efficiency will be determined by how much energy is required to produce the desired lumens.

So How Many Lumens Do I Need in a Room?

Unfortunately, the answer to this question isn't 100% straight forward. How many lumens you'll need depends on the answer to your first question. If for, example, you need adequate lighting for tasks like cooking, reading or working, then you'll need more lighting than a porch or living room. Here are a few steps you can take to ensure optimal lighting in every room:

1. Measure your room sq. footage

Determining how many lumens you'll need in a room starts with figuring out how much surface area there is in your room. To do this, measure the length along the base of each wall in your room and multiply them to find the surface area in sq. feet. If you have a complicated room structure, you may need to break the floor plan into easy to measure squares or triangles or refer to your floor plan details.

2. Multiply the surface area by recommended foot-candles to find your lumen requirement

A foot-candle is a number that describes how bright a light source appears from one foot away. Depending on the purpose of your room a higher or lower number of foot candles is recommended. Select a recommendation based on your room of choice from the list below and multiply that number by the surface area of your room to find the approximate number of lumens required to light that room.

• Workspace or garage: 100-foot candles
• Kitchen countertops: 80-foot candles 
• Bathroom: 80-foot candles 
• Office or home office: 80-foot candles
• Dining room: 40-foot candles
• Kitchen: 40-foot candles
• Living or family room: 20-foot candles
• Bedroom: 20-foot candles 
• Hallway: 10-foot candles

Example: 110 sq. ft. living room lighting requirement= 110x20=2200 lumens.

What types of bulbs do I need?

Now that you have a solid estimate of how much light your room in question requires, the next logical step is determining what type of bulb you should pick for the impact you are searching for. Let's take a quick look at the most common bulbs you'll find right now.

LED Bulbs

LED stands for light-emitting diode and is a type of light bulb that has grown tremendously in popularity in recent years. The standard LED bulb is around 75% more energy-efficient than a standard incandescent light bulb.

LED bulbs primarily produce directional lighting, so the standard LED bulb is best suited for task lighting as opposed to ambient lighting. Recently, LED bulbs have begun compensating for their deficiencies in diffuse lighting by clustering a few LEDs into one bulb, mimicking a diffuse light display, but these bulbs can be 6 times more expensive than normal LED bulbs.

LED bulb pros:

• Usually cheap
• Extremely long-life span (10-20 years on avg.)
• Energy efficient (9-watt LED is equivalent to 20-watt incandescent)
• Effective task/spot lighting

LED bulb cons:

• Can be expensive when used for diffuse lighting

Halogen Bulbs

Halogen lights are similar in function to incandescent light bulbs, in that, they produce light from a filament that is heated until it glows. Unlike incandescent bulbs though, halogen light bulbs generally consume very minimal amounts of electricity. In fact, they can consume anywhere from 25-80% less electricity than comparable incandescent bulbs.

Halogen bulbs give off a light that is very similar in nature to natural white light, so they are very effective for task lighting. The light produced by halogen bulbs is also naturally diffuse - unlike LEDs, which are directional - so halogen bulbs can be used for ambient lighting.

Halogen pros:

• Fully dimmable in most cases
• Similar light profile to natural daylight
• Available in 5-500-watt sizes
• Extremely energy efficient

Halogen cons:

• Get extremely hot (not safe for tabletop work)
• Natural oils from the skin can cause the bulb to shatter (handle with gloves when possible)
• Short lifespan in comparison to other modern bulbs (2-3 years on avg.)

Compact Fluorescent bulbs

Fluorescent bulbs have evolved from their original tubular, flickering, buzzing progenitors into a form that is like more traditional light bulbs. While still tubular, modern compact fluorescent bulbs are shaped to mimic the light display of other bulbs.

Compact fluorescent bulbs can go toe to toe with LEDs and halogen lights regarding energy efficiency, being up to 75% more efficient than traditional incandescent bulbs. Compact fluorescent bulbs do come with one major caveat - they contain trace amounts of mercury, so you'll need to be extra careful handling broken bulbs.

Compact Fluorescent bulb pros:

• Extremely energy efficient (14-watt CFL ~ 60 watt incandescent)
• Long life expectancy (7-9 years on avg.)
• Available in a variety of sizes (3-120 watts)
• Available in a range of temperatures and brightness levels

Compact Fluorescent bulb cons:

• Contains trace amounts of mercury
• Not always dimmable
• Can take a while to "heat up" to full brightness

Incandescent bulbs

Contrary to popular belief, incandescent bulbs are not extinct or completely unavailable. By and large, these bulbs are no longer produced anywhere in the first world, however, you can still purchase what remains online or in certain stores. Incandescent light bulbs are best used for ambient lighting and produce light that complements skin tones really well.

Incandescent bulb pros:

• Produces soft, warm light
• Comes in a variety of sizes and wattages
• Complements skin tones well
• Fully dimmable

Incandescent bulb cons:

• Short life span (1-2 years)
• Produces a lot of heat (hot to the touch)
• Consumes more energy than any other light bulb

What is Light Temperature and Why Does It Matter?

We've spoken about a couple of types of bulbs that are hot to the touch, but in this case, temperature actually referrers to color. Color temperatures are defined using a unit called "Kelvins". In a nutshell, the higher the Kelvin rating, the whiter the temperature of the color (yes, it's a little counter-intuitive).

There are three primary color ranges that we'll encounter in our search for optimal lighting. Let's take a quick look at them.

Soft White

The first of these color ranges is soft white, which starts at 2700K and ends at 3000K. Soft whites are most similar to incandescent bulbs and are excellent at highlighting colors in a room. Soft whites are very "gentle" making them extremely good for ambient lighting in places like the dining room or a bedroom. They also do very well in generating a "cozy" feeling on porches or in A/V rooms.

Cool White/Bright White

Cool or bright whites start off at 3500K and end at 4100K. These whites are slightly whiter than soft whites - which tend to have a hint of yellow - and make for excellent lighting in workspaces. Consider using cool whites in areas where you'll be performing tasks like cooking, reading or handy work. Cool whites are also well suited for security and outdoor lighting.

Daylight

Our final color temperature category is known as daylight. Light bulbs in this category tend to have a blue/white appearance and resemble sunlight at noon on a day free of cloud cover. This temperature is indisputably the most effective light for task lighting and accent lighting.

A Quick Recap

We've covered a lot about lightbulbs in this guide, so here's a quick recap to keep everything fresh:

• A bulb's brightness is determined by lumens - not wattage, pay special attention when purchasing
• How many lumens you require can be calculated by multiplying the surface area of your room by your recommended foot-candles
• Most modern bulbs are very energy efficient
• Compact fluorescent bulbs contain trace amounts of mercy, so be careful when handling broken bulbs
• Color temperature makes significant differences in light quality
• Soft whites are best for highlighting colors and skin tones
• Cool whites are effective for task lighting
• Daylights are exceptional for perimeter and security lighting