Let's Get Lit
I recently found out that getting or being “lit” is not commonly used as the past participle of light, but instead it references a high level of intoxication. I like talking about home inspection topics so let’s stick with lit as is to light.
Thomas Edison and his team developed the first incandescent light bulb back in 1879 and boy did that help people get lit... The first light bulbs consisted of a carbon filament that was inside a glass bulb that was under vacuum. The reason the bulb was under vacuum was because oxygen would react with the filament and cause a chemical reaction that would greatly reduce the life of the light bulb. When electricity would flow through the filament it would produce both light and heat.
In 1910 the manufacturing process of tungsten filament was improved allowing the tungsten filament to be manufactured in a much more economical way. Tungsten is still the element used in today’s modern incandescent lights.
From incandescent lights came fluorescent tube lights. A fluorescent tube doesn’t have a filament but instead it heats a special gas that has been trapped inside the bulb. Fluorescent tubes then lead to the invention of compact fluorescent (CFL) bulbs. CFL bulbs were the same size as traditional incandescent bulbs and allowed consumers to replace their incandescent bulbs with a more energy efficient technology.
In the early 1960’s Nick Holonyak accidently invented a red light emitting diode (LED) while trying to create a laser. Holonyak then patented the discover for use as a light fixture. Yellow and blue LEDs were invented a few years later. Almost thirty years after the red LED was discovered a Nobel prize was awarded to the inventors of the blue LED. If the blue LED was coated with phosphor it would produce white light, and that is when the boom of LED lighting began.
Now that we know the history lets dive into the practical applications of lighting in the house because when you’re deciding on a lighting solution there are a few factors that you might want to consider; Price, Lifespan, Energy Efficiency, and Safety.
Price
Since incandescent bulbs have been manufactured for almost 150 years they win in the category of least expensive on the shelf. However, when you add the short lifespan and couple that with higher energy costs, the incandescent bulb quickly loses the lead. CFL bulbs are also less expensive on the shelf, but they too fall short of LEDs in the long run. The winner in the price category becomes the LED bulb.
Lifespan
If an average LED can easily last 25,000 hours what does this really mean? If we used the bulb six hours a day every day then this bulb could last roughly 11.4 years. Using the same example, a CFL bulb would last 3.6 years and an incandescent bulb would last 0.5 years. The winner in the Lifespan category is the LED bulb.
Energy Efficiency
Incandescent bulbs are highly inefficient. Light bulbs are designed to produce light, but if you ever had an Easy Bake Oven growing up, you also know that incandescent bulbs produce a significant amount of heat. The production of heat is a clear indication of the bulb’s inefficiency. To crunch the numbers a 60-watt incandescent bulb produces the same amount of light as a 14-watt CFL bulb which produces the same amount of light as a 7-watt LED bulb. The LED bulb is the clear winner of the energy efficiency category
Safety
As previously stated, incandescent bulbs produce a significant amount of heat. This heat could cause a fire if combustible materials are placed too close to the bulb. Many manufactures deliberately design light bulb fixtures in such a way that oversized light bulbs can’t physically fit into the light fixture. This will prevent the fixture from getting hotter than it was rated for thus reducing the likelihood of a fire. CFLs are relatively safe even though concerns have been raised about UV radiation and Mercury exposure. These concerns are real, but the possibility of injury is extremely low. LED lights are by far the safest option and they win in every other category. LED and CFL bulbs both win in this category, and the real take away is that incandescent bulbs can be unsafe.
Looking at market trends it is clear that LED sales have dwarfed CFL and Incandescent bulb sales, so the rest of this article will focus on LEDs and what you need to know. Shape, brightness, color temperature, and dimmability are the main differentiators between LED bulbs.
Shape
Light bulbs come in many shapes and you may hear someone say that they need an A19 bulb, or a PAR30 bulb, or maybe CA10. It’s great that there are names for bulbs but what does it mean. ‘A’ (Arbitrary) bulbs are the most common style of light bulb and it is what would pop up above a cartoon character’s head when they came up with an idea. ‘R’ (Blown Reflector), ‘BR’ (Bulged Reflector), and ‘PAR’ (Sealed Beam) bulbs are all considered to be directional lights and you would commonly see them in recessed lighting or exterior flood lights. ‘C’ (Candle), ‘CA’ (Candle Angular), and ‘CT’ (Candle Twisted) bulbs are decretive lights that look like candles, but with slight decorative differences.
The number after the bulb shape code refers to the physical size of the bulb in 8ths of an inch. This means that a A19 bulb is 19/8” wide or written a different way, 2 3/8” wide. The letter code doesn’t change a thing, so a PAR30 would be 30/8” or 3 6/8” wide and a CA10 would be 10/8” or 1 2/8” wide. There are many different bulb shape codes that also refer to the size and connection method used by the base.
Brightness
A lightbulbs brightness is measured in lumens which is the amount of light emitted per second. To help consumers determine how many lumens their bulb should have many bulbs will state their equivalent brightness compared to an incandescent bulb. The reason for this is because incandescent bulbs have been used for almost 150 years and LEDs have only seen a surge in sales over the last 15 years. When buying an LED bulb, the consumer may read that a bulb is a 60w equivalent and what this means is that the 60-watt incandescent light bulb produces the equivalent amount of light as compared to a 13-watt LED bulb which is about 800 Lumens. Eventually equivalent values will be dropped, and consumers will only reference the bulb shape and brightness in lumens.
Color Temperature
When buying LED bulbs, you may be presented with soft white and daylight color options. The measure of light color uses the unit of Kelvin. On the Kelvin scale a candle would produce a color of 1,900K which is a very yellowish orange color. The soft white bulbs will have a color around 2,700K which is almost identical to a traditional incandescent bulb. A daylight bulb will be around 5,500K which is almost an exact replica of natural sunlight. It is often said that a daylight bulb is more “Blue” than a soft white, but that is a misrepresentation because even though it is closer on the scale to blue it is in fact most accurately portrayed as a true white. It should be said that daylight bulbs are white and that soft white bulbs are actually yellow.
An interesting thing about using 5,500K LED bulbs is that a well-documented treatment of seasonal affective disorder (SAD) is the use of 5,000K – 6,000K lights shining in your field of view but not directly into your eyes. This can help your brain respond the same way it might on a beautiful sunny day and help you to overcome feeling of depression during the winter months. The treatment is usually for 30 minutes every day and it uses a light box with over 10,000 lumens of light being produced inside. A room that you spend several hours in each day that is also well-lit with 5,500K LED bulbs could help to reduce the effects of SAD.
Dimmability
Not all LED bulbs are dimmable. Make sure that the packaging specifically states dimmable, or it may not work with a traditional dimmer. Traditional dimmers found in homes dim a light by diverting electricity into a resistor which converts excess energy into heat and dissipates that heat into the air. Modern dimmers use a Pulse Wave Modulator (PWM) which rapidly turns on and off the circuit at about 240hz or 240 times per second. This is so fast that the human eye can’t see it because we can only perceive less than 60hz. All LEDs will work on a PWM but not all LEDs will work on a traditional dimmer because an LED needs a set amount of voltage to be able to turn on. If you try to use a non-dimmable LED on a traditional dimmer the LED will dim to a point and then abruptly turn off. The LED may also flicker in a very noticeable way. Lower than required voltage will damage the LED and reduce its lifespan.
Hopefully this article will help you to have a safe, happy, and energy efficient home for many years into the future. Thank you for reading our article. If you have any questions about residential home inspections, please send us a message. If you would like Two Moose Home Inspections to inspect your property, feel free to schedule an inspection.