Light Bulb Prices Burning Your Wallet? Comparing Halogen Bulbs to LEDs

By Vernon Trollinger, April 14, 2014, Energy Efficiency, Save Money

No doubt you’re already aware that LED bulbs use far less electricity compared with incandescent bulbs. That’s because the old-school incandescent bulbs use electrical resistance to heat the filament until it glows. Consequently, about 90% of the energy an incandescent bulb uses is converted into heat.

Light Bulb Prices Burning Your Wallet? Comparing Halogen Bulbs to LEDs

LED Light

But you might not have heard of of halogen bulbs or be aware of the difference between them and other options. They are designed to last longer than standard incandescent bulbs – about 2000 hours, compared to the 1000 hours of the traditional light bulb. This is because halogen bulbs are filled with a special gas that redeposits the vaporizing tungsten filament wire back onto the filament and not on the side of the glass bulb. Otherwise, the tungsten wire vaporizes away until the wire breaks apart or “burns out.” Halogen bulbs do this by using lots of heat. Depending on how many you use in your home for lighting and how long you use them for, halogen lamps have the potential to add to your home’s summer cooling load.

Light Bulb Prices Burning Your Wallet? Comparing Halogen Bulbs to LEDs

Base Temperature of Halogen Fixture

With this idea in mind, I decided to find out the surface heat amounts of halogen bulbs versus LED bulbs to see if we could determine if the difference in bulbs could create more energy savings. I began the experiment with a confined track light fixture composed of a small conical shade made of thick heat-resistant frosted glass (and doubtlessly hard to replace) sized to fit a 20 watt G8 base MR-16 style (MR-16 is the reflector) halogen bulb. Because the shade has no vents, the whole fixture traps heat and grows hot to the touch.

To find out the basic operating temperature, I used an infrared thermometer to find the hottest surface on the exterior of a similar bulb without a shade covering it. This was where the glass reflector met the porcelain base assembly. As you can see in that picture, the temperature was 126°F.

Light Bulb Prices Burning Your Wallet? Comparing Halogen Bulbs to LEDs

LED on Left; Halogen on Right

The LED bulb I compared it to was a 2.5 watt bulb with a G8 base made by Meridian Electric Company. To be honest, nobody makes a G8 MR-16 sytle LED lamp. However, I needed an LED lamp in that style for two reasons. First was to make a fair comparison. Second, the light fixture uses a clip to fit around the MR16 reflector in order to hold the lamp in place. So, I epoxied the Meridian bulb into an MR16 reflector scavenged from a burned out halogen bulb (that’s a how-to-article all by itself).

In this photo, the LED bulb is on the left, the halogen is on the right. The LED and halogen bulb are close in color temperature with LED being a tad bluer. They also put out nearly the same amount of light, the halogen was about 200 lumens while the LED put out 185. Apart from hugely different wattage, this is where the similarities end.

Light Bulb Prices Burning Your Wallet? Comparing Halogen Bulbs to LEDs

Halogen Temperature on left; LED Temperature on right

The Reveal
I took the temperature readings from the back of the light fixtures so their positions are reversed in this photo. On the left now is the halogen bulb, and you can see the temperature of the shade cover is 164.9°F! The temperature of the LED bulb shade cover is 78.6°F. (The room temperature that day was 70 °F, surface temperature of the ceiling was the same)

So, what does this mean? I have 10 of these halogens used to illuminate one room. In terms of electricity use for lighting, that adds up to 200 watts. While that might not seem huge, the wattage does add up — it only takes 10 hours to use 2 kWh. These halogens also tend to burn out after 8 months, adding about $3 each for replacement costs. The LED bulb uses one-eighth of the energy and lasts about 3 years. So even though LED bulbs cost three times as much to buy, they pays for themselves in only a year or two.

The real shocker is just how much heat the halogens dump into a room, especially if their fixtures trap and build heat. Ten fixtures all radiating 164.9°F are adding to my home’s cooling load. In reality, it’s probably not a screaming huge amount, possibly analogous to leaving a window open during a 90° day.

Yet, while that might not seem outrageous, it does add over time to the overall cooling costs. This not only applies to track lights, but also to recessed or can lighting found in many homes where bright light is wanted for task lighting (like the kitchen). Halogen lights in recessed light fixtures may trap enormous amounts of heat and bit-by-bit add onto your home’s cooling load.

Thus, before summer heat really gets fired up, we recommend that you take a good look at your lighting and think about the heat it gives off. If you’ve got halogens or even regular incandescent bulbs, don’t wait until they burn out. Replace them with CFLs or LEDs for cooler savings.

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About 

A native of Wyomissing Hills, PA, Vernon Trollinger studied writing and film at the University of Iowa, later earning his MA in writing there as well. Following a decade of digging in CRM archaeology, he now writes about green energy technology, home energy efficiency, DIY projects, the natural gas industry, and the electrical grid.

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Comments (1)

 

  1. Steve says:

    Great test to demonstrate the difference. Thanks!

    Now I’m a big fan of LED myself, but thought it was fair to point something out. In a factory setting, if there isn’t much natural light, maybe the lights are on all day and really do add to cooling costs in the summer … but do they equally reduce heating costs in the winter?

    Meanwhile, in a home, where we typically have natural lighting in every room and the need for running lights is greatly reduced in the day time, it seems to me we use lights far less in the summer and much more in the winter. So those hotter bulbs might actually save you money in terms of heating and cooling combined.

    Now, the energy savings of LED far outstrips any issue with heating and cooling, so again, I’m a fan of the switch to LED. But I’ve read many people talk about the cooling issue, yet I wonder if that’s really an issue at all.