Five things you must know about LED lights

1. LEDs are cooler.

When you're running fans or an air conditioner this summer, having burning-hot incandescent bulbs just makes it harder to manage the heat. LEDs run much cooler than incandescent bulbs and significantly cooler than CFLs.

Online retailer EnergyCircle actually measured the difference and found that a halogen bulb, a type of incandescent bulb, ran at 327 degrees! A Cree LED downlight was measured at 107 degrees and a Philips Par38 CFL worked at 167 degrees.

That's not to say that heat isn't at all an issue. LED lights do get hot but the heat is dissipated by metal heat sinks that wick away the heat from the light source itself. Keeping them cool with heat sinks or even liquid cooling, as Switch Lighting is doing, is important to ensuring they last as long as advertised.

You get instant full light.

You get the full brightness of an LED light when you turn it on, which is an advantage over CFLs in a couple of ways. For starters, you don't need to wait for full light if you're running in and out of a room. But frequent cycling also degrades the life of CFLs, one of the reasons that CFLs in some cases don't last as long as expected.

I've become more conscious of this and put LEDs in places where lights are cycled on and off quickly. CFLs, meanwhile, are in light fixtures and lamps which typically stay on for extended periods. Consumer Reports found turning CFLs on and off in less than 15 minutes degraded their life.

LEDs don't attract bugs.

Pixi Lighting, which makes LEDs, lists "no bugs!" (that is, insects) as one of the reasons to use LEDs. But if you look at discussions online, it's not so clear-cut./p>

The stated reason that bugs don't fly toward LEDs is because bugs are attracted to ultraviolet light and at least some LEDs don't give off this type of light. But that's not universally true for all types of LEDs, according to people who have commented online. In one discussion, an employee from EnergyCircle said that most residential LED bulbs give off almost no UV light.

In an unscientific test last night at my house, I saw moths and mosquitoes fly right past my outdoor LED bulb; they were not attracted to the light. Consumer LED bulb maker Pharox advertises its bulbs as having no UV, so it's something worth checking when you're shopping around.

You will need to learn some lighting lingo.

We still talk about 60-watt and 75-watt equivalent bulbs because that's what we're accustomed to. But some manufacturers are using new labels that give people far more information than brightness, which is worth understanding as lighting gets more diverse.

Lumens, of course, measure the amount of light, with a 60-watt equivalent giving off at least 800 lumens. But LEDs are also sold by color temperature, either warmer yellow light or cooler white light. And then there's color rendering index, with the highest being the best for light quality.

Warmer color lights will be more familiar since they're closer to the yellow glow of a CFL or incandescent. But I found I like the cooler, white light of the Lighting Sciences Group bulbs, rated at a cooler 3000 Kelvin, which I find a little cleaner. As for color quality, I can't put my finger on why, but I've been very happy with the light from a Pixi bulb which has a 96 color rendering index--higher than the others I have.