Are you still on the fence over which energy-efficient alternative to choose between LED and Compact Fluorescent Lamp (CFL)? Incandescent bulbs have proven to be costly and inefficient and they are being phased out. Roughly lighting our homes accounts for about one-quarter of our electricity bills, LEDs or CFLs can save you a lot of money. But which would you choose?
LED Advantages.
- Have no sensitivity to low temperatures and humidity. They can function under very low temperature conditions.
- LEDs are very durable – LEDs can handle jarring and bumping .They are solid state lights (SSLs) that are difficult to damage with physical shocks.
- LEDs use less power (watts) per unit of light generated (lumens). LEDs help reduce greenhouse gas emissions from power plants and lower electric bills.
- LED lights last longer, so even though you’re paying more at purchase, you buy fewer bulbs over time. New LEDs can last 50,000 to 100,000 hours or more. The typical lifespan for a CFL, by comparison, is 10-25% as long at best (roughly 10,000 hours)
- LED bulbs fit in standard light fixtures with no adaptor necessary.
- LED makes very nice lighting for effect and decorative purposes.
- They turn on instantly, there is no warm up time. They are thus ideal for purposely turning on and off because they respond rather instantaneously (there is no warm up or cool down period). They produce steady light without flicker. They are thus suitable to use with motion sensors that frequently activate and time out.
- Low heat emissions, typically 3.4 Btu’s/hour.
- Contains no Contains the TOXIC Mercury. Mercury is very toxic to your health and the environment.
- LED lights are RoHS (Restriction of Hazardous Substances Directive) compliant.
- LED lighting is directional (they emit light in a specific direction), they do not need diffusers or reflectors that trap lights. This helps increase LED efficiency for uses such as down lights (recessed down lights are common in residential kitchens, hallways and bathrooms) or task lighting.
- LEDs can be much smaller than other lights.
- LEDs can be designed to generate the entire spectrum of visible light colors without having to use the traditional color filters required by traditional lighting solutions.
- LEDs require far fewer accessory lamp parts.
- LEDs can be much smaller than other lights(less than 2mm in some cases) and they can be scaled to a much larger size. All in all this makes the applications in which LEDs can be used extremely diverse.
- LED’s produce light that renders a color similar (but not identical) to natural daylight, which is measured on a scale called Color Rendering Index (CRI). CRI’s range from 0-100, 100 being identical to natural daylight. Typical LED’s are around 70-95 CRI.
- LED has virtually zero maintenance costs and the frequency with which bulbs have to be changed out is by far the best on the market.
- LEDs are very easy to dim and options are available to use anywhere from 100% of the light to 0.5%. LED dimming functions by either lowering the forward current or modulating the pulse duration.
- LEDs are available in a wide range of color temperatures that generally span from 2200K-6000K (ranging from yellow to light blue).
LED Disadvantages.
- LED lights are relatively expensive. The up-front costs of an LED lighting project are typically greater than most of the alternatives.
- LED lights are directional, meaning they are excellent for lights as downlights, but not as suitable to table lamps. Some of the newer LED lights come with diffusers though to mitigate this.
- LED lights show degraded performance at significantly high temperatures and they require significant heat sinking, especially when in proximity to other sensitive components.
- LEDs fail by dimming gradually over time.
- LED efficiency drops as current increases. Heat output also increases with additional current which decreases the lifetime of the device. At higher power input (say above 40W, LEDs efficacy is indistinguishable from that of CFLs.)
CFL Advantages.
- CFL bulbs can fit in any standard light sockets without any adaptor.
- CFL lights generally represents a high efficiency way to provide lighting over a vast area (like warehouses and schools or commercial buildings).
- Fluorescent lights are omnidirectional. Omnidirectional lights produce light in 360 degrees. They can thus be used as table lamps.
- CFLs upfront costs are generally lower than LEDs.
- Newer CFL bulbs can be dimmed very effectively (down to about 15% of their normal light).
- CFLs light are available in a range of CCT (Correlated Color Temperature) values that can be adjusted by changing the amount of phosphor inside the bulb. Typical values range between warm white at 2700K to daylight at 6500K depending on the lighting requirement.
CFL Disadvantages.
- They are not RoHS compliant. Fluorescent lights contain toxic mercury. Mercury as well as the phosphor inside the bulbs are hazardous materials that present a waste disposal issue at the end of light’s life. Broken bulbs release a small amount of toxic mercury as a gas and the rest is contained in the glass itself.
- Fluorescent lights age significantly if they are frequently switched on and off. Typical lamp life for a CFL is about 10,000 hours but this can degrade as a consequence of frequent switching (turning on and off). It’s worth thinking about in the event that you are using CFLs in conjunction with motion sensors that frequently activate and time out.
- Fluorescent lights are non-directional, meaning that they emit light for 360 degrees. Thus, a large portion of this light is wasted (for example, that portion that is directed at the ceiling). They thus require fixture housings or reflectors to direct the emitted light
- Fluorescent lights require a ballast to stabilize the light. In the event that there is a minor flaw in the ballast the light may produce an audible hum or buzz.
- Fluorescent lighting emit a small amount of UV radiation. Ultraviolet light is known to cause fading of dyed items or paintings exposed to their light.
- CFLs light quality suffers significantly under very low temperatures.
- Compact Fluorescent Lights (CFLs) are designed to be small .Even so, they typically aren’t produced below roughly a centimeter in width.
- CFLs light are particularly fragile .Broken CFLs require special handling and disposal due to hazardous materials like mercury inside the lights.
- Fluorescent bulbs require regular relamping and ballast replacement in addition to the labor cost to monitor and replace aging or expired components.
- Have higher heat emissions of 30 Btu’s/hour as compared to LEDs 3.4 Btu’s/hour. CFLs release about 80% of their energy as heat.
- Fluorescent lights experience efficiency losses as the device ages and additional current is required to achieve the same lighting output.
Making Your Decision
Both are LEDs and efficient ways to light your home, and both work with all the sockets, lamps and fixtures you already own. If you enjoy a directional light for reading, cooking, or working at home, you might prefer the LED bulbs. For general home lighting, such as illuminating a room, CFL might be best.
When it comes to dimming LEDs, It is a common misconception that any LED lights can be dimmed with an LED dimmer. The driver circuitry must be designed with dimming in mind. Therefore, it is essential to choose lamps that the manufacturer describes as ‘dimmable’.
Tips on Dimmer Selection.
- Choose lamps from established lighting manufacturers. Aside from dimming considerations, established brands are also more likely to offer better product warranties, longer lamp life and more customer support.
- Read the label and select the dimmable lamps with the highest maximum lumen output.
- DO ask manufacturers about compatibility.
- DON’T use a standard dimmer.
- DON’T buy your luminaires without first selecting a dimmer. It’s important to select a dimmer that can control the total wattage and quantity of lamps you want to dim.
