LED Lightbulbs 101

One of the easiest swaps to make with an old home to reduce energy costs is to switch over to energy efficient light bulbs.  There are a few options on the market, but the real contender in our house is definitely LED bulbs.  There are a few reasons for this, and the biggest is that these use about 10% of the energy of an incandescent bulb with an equal amount of brightness.  But there are a few things to consider when making the switch beyond stylistic decisions.  

Wattage is how much electricity is used in a circuit.  In AC current -wall plugs, not batteries- the wattage is also voltage x amperage.  Voltage does not change in a wall circuit, but amperage can.  So, a 60w incandescent light bulb plugged into a 120 volt circuit uses 1/2 an amp per hour  (120 x 1/2 = 60).  For a modern circuit breaker, when a circuit meets or exceeds the rated amperage on the breaker, it will turn the circuit off.  So, on a 15 amp breaker, 30 incandescent light bulbs that use 60 watts (or 1/2 an amp with 120 volts) should trip the breaker.  If an LED replacement uses roughly 10% of the power of an incandescent, it would take 300 bulbs!* Or it'll save the energy.  

*Keep in mind, this is the basics!  Please don't try to plug in enough light bulbs to trip your breakers. Some of the numbers are simplified, so individual circuits and bulbs vary. 

​What is a Lumen?  How does color temperature affect the bulb?

When buying LEDs, these are the two biggest factors to consider.  Here is my quick mental guide for each of these!

Lumens are how bright a bulb is.  Luckily, most manufacturers put the incandescent "equivalent" for brightness on the packaging.  Basically, 450 Lumens has around the same brightness as a 40w incandescent bulb, 800 Lumens has the brightness of a 60w incandescent bulb, and 1200 Lumens has the brightness of a 100w incandescent bulb.  The higher the Lumens, the brighter the bulb.

The second thing to consider is color temperature.  There are really just a few numbers to know, and manufacturers all have slight variations, so rounding numbers is okay too when looking at individual bulbs.  The color temperature moves along the light spectrum from reds to greens.  2200 is often called an amber bulb, and it's close to the color of candlelight or a wood fire.  2700 is the color temperature that is closest to a soft white incandescent bulb, and 3000 is closest to bright white incandescent bulbs.  4000 is the brightness of a daylight bulb, and anything beyond that gets into awkward fluorescent coloring. 

Lumens to Incandescent Bulb Equivalent 
450 Lumens = 40w 
800 Lumens = 60w
1200 Lumens = 100w

Color Temperature
2200 = amber bulb or candlelight
2700 = soft white (warm) incandescent bulb
3000 = bright white (warm) incandescent bulb
​4000 = cool white bulb
​5000 = daylight bulb

What Causes Color Shift in Holiday Lights?

Holiday lights are another ballgame with LEDs, but they are an important thing to note this time of year!  One of the biggest benefits -beyond energy savings- with shifting holiday lights to LEDs is that they don't produce heat in the same way that an incandescent bulb does.  So, switching to an LED can reduce the risk of fire especially with more intense bulbs, like the C9 size pictured.  

LEDs give off light by emitting photons through diodes.*  Different products are used to create different colors, or the silicone casing around the diode is dyed to change the color of the bulb.  Because two different things affect the color of each bulb, some funky things can happen when looking at individual strings of lights.  Because each manufacturer and even each facility makes their bulbs slightly differently, one warm white string may look slightly different from another, or they may photograph completely differently while looking the same to the naked eye.  AC current flows through bulbs basically like a pulse.  So, if one strand has a different pulse than another - or a different pulse than a digital camera - there can be some shifting in how the light is picked up by the lens. 

What I do when adding lights to my trees is to add each strand like tinsel: they spiral around the tree from the bottom to the top and all plug into a surge protector (which has extra fire protection).  This helps to blend each strand and make the color shift less noticeable.  But it's not always practical with larger trees. 

*Remember, this is LEDs 101!  There is more to it, but these are the need-to-knows for practical application.

​Why do my LEDs flicker?

Because LEDs run on so little energy, dimmer switches can be fickle.  Dimmers don't necessarily reduce the available voltage going to a bulb, but they do alter that pulse of AC current.  Since currents move through wiring in waves, dimmers work by blocking part of the wave from reaching the bulb.  Not all LED bulbs are designed for this manipulation, and not all dimmers can effectively dim a low wattage bulb.  So, if an LED bulb is flickering, the first thing to check is that the bulb was made for dimming,  This is usually noted on the packaging if not on the bulb itself.  If the bulb is a dimmable type, then check your dimmer switch.  Dimmers don't have an indefinite lifespan the way a standard switch does, so even with a dimmable bulb an LED will let you know it's time to change out the switch.  I try to keep all of my dimmers LED-compatible since it's better for the bulb as well.