Wednesday, December 18, 2013

The Energy-Saving Myth of LED Holiday Lights

If you use strands of lights for holiday decorating, you may be wondering whether you should trade in your sets of traditional incandescent lights for the new LED lights that have become popular.

The answer is no if:
  • Your incandescent light sets are in good condition.
  • You have (or know how to get) spare bulbs for your current lights.
  • You use the lights sparingly...
    • Only a few hours per day.
    • Only a few weeks per year.
  • You use the lights indoors only during cold weather days when you heat your home.
Understand that the incandescent lights you use now convert most of the electricity into heat.  So that any energy savings you might realize by switching to LED lights will mostly be offset by an increase in the energy you'll use to heat your home.  And if your home uses electric heat, you'll never re-coup your savings.

So by all means trade in your traditional incandescent lights for the new LED lights if:
  • You use the lights outdoors or in unheated areas.
  • You use the lights when the weather is warm.
  • You can't find replacement bulbs for your current set.
  • The wiring in your current set has cracked or missing insulation.
  • You use more lights than your house wiring can handle...
    • When you turn them on a fuse blows (or the breaker trips).
    • The outlet or extension cord feels very warm.
I continue to use two sets of incandescent lights that are rated at 75W each.  They use special C7 bulbs that are designed with an internal bimetallic strip.  When the light is on, the strip heats up and bends to interrupt the current flowing to the filament.  This enables each one to blink on and off randomly independent of the others.  It's a lovely effect, one I've not seen duplicated with LED sets.

Besides, the LED light sets that I've seen have an annoying flicker to them.  LEDs turn on only when current flows in one direction.  They remain dark for half the cycle unless a special "full-wave rectifier" has been included in the design.  Unfortunately, the packaging won't tell you anything about the design, so you have to take your chances.  Be sure to buy light sets at a store with a good return policy and save your receipt.

I hope this helps you in some way!

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