Most people would really like to see the comparison if possible. Induction has, I think lost it's momentum.So a new LED system would save tons of electricity and take fewer fixtures to light the existing area. We find seeing is believing and a chart would be awesome.
Let's take a look at the information on a typical 400 watt metal halide bulb. While specifications may vary, a visit to a popular online website that sells Metal Halide bulbs shows that a brand new bulb has the following specifications:
- Color Temperature: 4000K
- Initial Lumens: 32,000 to 36,000
- Life Hours: 20,000
A recent white paper by the Dark Sky Society rated the mean lumens for a 400W Metal Halide to be 20,500 lumens and the rated life expectancy to be around 15,000 hours. But for purposes of this discussion, we will stick with the numbers we are familiar with.
LED vs Metal Halide Comparison Chart
|Topic||LED Notes||Metal Halide Notes||Winner|
|Correlated Color Temperature (read more here)||LEDs are available in a wide range of color temperatures that generally span from 2200K-6000K (ranging from “warm” yellow to light or “cool” blue).||Metal halide lamps generate a very cool white light. They are available in color temperatures as low as 3000K. Some metal halides are available with extremely cool color temperatures up to 20,000K.||-|
|CRI (read more here)||CRI for LED is highly dependent on the particular light in question. That said, a very broad spectrum of CRI values is available ranging generally from 65-95.||Metal halides are perhaps the best source of high CRI white light on the market.||Metal Halide|
|Cycling (Turning On/Off)||LEDs are an ideal light 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.||Metal Halide lights require a notoriously long warm up period. Many stadiums have traditionally relied on metal halide lights but the bulbs can take 15-30 minutes to get to full operating power.||LED|
|Dimming||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. LED lights are not compatible with traditional incandescent dimmers (which lower the voltage sent to the light) so you need to purchase LED dimmer switches as well if you want to dim.||Metal halide lights can be dimmed through the use of different electric or magnetic ballast but the process changes the voltage input to the light and can consequently alter the light characteristics. Generally speaking metal halide lights are less efficient when run at less than full power. In some cases dimming can also cause the light to prematurely expire.||LED|
|Directionality||LEDs emit light for 180 degrees. This is typically an advantage because light is usually desired over a target area (rather than all 360 degrees around the bulb). You can read more about the impact of directional lighting by learning about a measurement called “useful lumens” or “system efficiency.”||Metal Halide lights are omnidirectional meaning they emit light for 360 degrees. Much of these emissions must be reflected and/or redirected which means losses and lower overall system efficiency.||LED|
|Efficiency||LEDs are very efficient relative to every lighting type on the market and extremely efficient relative to incandescent bulbs. Typical source efficiency ranges 37 and 120 lumens/watt. Where LEDs really shine, however, is in their system efficiency (the amount of light that actually reaches the target area after all losses are accounted for). Most values for LED system efficiency fall above 50 lumens/watt.||Metal Halide lights have average efficiency (75-100 lumens/watt source efficiency). They lose out to LEDs principally because their system efficiency is much lower (<30 lumens/watt) due to all of the losses associated with omnidirectional light output and the need to redirect it to a desired area.||LED|
|Efficiency Droop||LED efficiency drops as current increases. Heat output also increases with additional current which decreases the lifetime of the device. The overall performance drop is relatively low over time with around 80% output being normal near the end of life. Recent advances by researchers who have identified the reasons for droop in LEDs look to reduce losses even further.||Metal Halide lights also experience efficiency losses as the device ages and additional current is required to achieve the same lighting output. Efficiency losses are greater than LEDs and the degradation time shorter in the case of Metal Halides.||LED|
|Emissions (In the Visible Spectrum)||LEDs produce a very narrow spectrum of visible light without the losses to irrelevant radiation types (IR, UV) or heat associated with conventional lighting, meaning that most of the energy consumed by the light source is converted directly to visible light.||Metal Halide lights produce relevant amounts of both IR and UV radiation.||LED|
|- Infrared||None||Metal Halide lights emit IR radiation which is a waste of energy for the purposes of regular illumination.||LED|
|- Ultraviolet||None||Metal Halide lights emit UV radiation and require a filter built into the bulb to keep these emissions from being radiated into the atmosphere. These filters are required to prevent fading of dyed surfaces exposed to metal halide light otherwise serious damage can occur to light fixtures or even human beings and animals (e.g. serious sunburn or arc eye).||LED|
|- Heat Emissions||LEDs emit very little forward heat. The only real potential downside to this is when LEDs are used for outdoor lighting in wintery conditions. Snow falling on traditional lights like HID will melt when it comes into contact with the light. This is usually overcome with LEDs by covering the light with a visor or facing the light downward towards the ground.||Metal halide bulbs emit a significant amount of heat (roughly 10-15% of the total energy consumed is emitted as heat). In some circumstances this could be beneficial, however, it is a generally a bad thing as heat losses represent energy inefficiencies. The ultimate purpose of the device is to emit light, not heat.||LED|
|Failure Characteristics||LEDs fail by dimming gradually over time. Because LED lights typically operate with multiple light emitters in a single luminaire the loss of one or two diodes does not mean failure of the entire luminaire..||Metal Halide lights exhibit an end-of-life phenomenon known as cycling where the lamp goes on and off without human input prior to eventually failing entirely. For this reason in many applications (such as a sporting stadium) metal halide lamps must be changed out prior to the end of their useful life.||LED|
|Foot Candles (read more)||Foot candle is a measure that describes the amount of light reaching a specified surface area as opposed to the total amount of light coming from a source (luminous flux). LEDs are very efficient relative to every lighting type on the market. Typical source efficiency ranges 37 and 120 lumens/watt. Where LEDs really shine, however, is in their system efficiency (the amount of light that actually reaches the target area after all losses are accounted for). Most values for LED system efficiency fall above 50 lumens/watt.||Foot candle is a measure that describes the amount of light reaching a specified surface area as opposed to the total amount of light coming from a source (luminous flux). Metal halide lights are very efficient compared to incandescent lights (75-100 lumens/watt source efficiency). They lose out to LEDs principally because their system efficiency is much lower (<30 lumens/watt) due to all of the losses associated with omnidirectional light output and the need to redirect it to a desired area.||LED|
Note: Foot Candle ratings are very application specific and vary case by case so relative performance is difficult to generally quantify.
|Lifespan||LEDs last longer than any light source commercially available on the market. Lifespans are variable but typical values range from 25,000 hours to 100,000 hours or more before a lamp or fixture requires replacement.||Metal Halide lights have an better lifespan relative to old technology like incandescent lights but they have a short lifespan compared to LED. Typical lifespan values range from 6,000 hours to 15,000 hours before a bulb requires replacement. Note: sometimes metal halide lights need to be changed out before the end of their useful life to preempt serious degradation effects like color changes or cycling.||LED|
|Lifetime Costs||LED lighting has relatively high initial costs and low lifetime costs. The technology pays the investor back over time (the payback period). The major payback comes primarily from reduced maintenance costs over time (dependent on labor costs) and secondarily from energy efficiency improvements (dependent on electricity costs).||Metal halide lights are relatively cheap to purchase but they are relatively expensive to maintain. Metal halide bulbs will likely need to be purchased several times and the associated labor costs will need to be paid in order to attain the equivalent lifespan of a single LED light.||LED|
|- Maintenance Costs||As a result of the operational lifetimes of LEDs and the frequency with which bulbs have to be changed out, LEDs are by far the best on the market in regards to lifetime costs.||Metal halide bulbs require regular relamping and ballast replacement in addition to the labor cost to monitor and replace aging or expired lights several times within the typical lifespan of a single LED.||LED|
|- Upfront Costs||LED light costs are high but variable depending on the specifications. The typical 100W-equivalent LED light costs somewhere between $10 and $20.||A 100W Metal Halide light costs somewhere between $10 and $30 per bulb depending on the specifications.||-|
|Shock Resistance||LEDs are solid state lights (SSLs) that are difficult to damage with physical shocks.||Metal halide bulbs are relatively fragile. Perhaps more importantly, broken metal halide bulbs require special handling and disposal due to hazardous materials like mercury inside of many lights.||LED|
|Size||LEDs can be extremely small (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.||Metal halide bulbs can be small but typically aren’t produced below roughly a centimeter in width. The size of the lamps is limited by the wattage and light output required for a given application.||LED|
|- Cold Tolerance||Minus 40 Degrees Celsius (and they will turn on instantaneously).||Minus 40 Degrees Celsius.||LED|
|- Heat Tolerance||100 Degrees Celsius. LEDs are fine for all normal operating temperatures both indoors and outdoors. They do, however, show degraded performance at significantly high temperatures and they require significant heat sinking, especially when in proximity to other sensitive components.||We couldn’t find any objective data on metal halide bulb performance in high temperature situations. If you have any information please contact us.||-|
|Warm-Up Time||LEDs have virtually no warm-up time. They reach maximum brightness near instantaneously.||Metal halide lamps require a noticeable warm-up time that varies depending on the light. Metal halide lights for sporting stadiums might take 15-20 minutes to arrive at maximum brightness.||LED|
|Warranty||Often 5 to 10 years.||Typically 1-2 years.|
Hopefully, from this information you were able to gather that the LED is generally the worthier opponent when matched up against HID lights. Though it’s important to note both Metal Halide and High Pressure Sodium lights do offer some benefits over LEDs for specific applications and smaller budgets.
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