Test Your Energy Saving Know-How

Washing dishes by hand typically uses more energy than the dishwasher. Photo by Catt Liu.

When it comes to saving energy, it can be confusing to figure out what works and what doesn’t. Let’s take a look at seven common energy-saving claims and sort fact from fiction.

1Claim #1:
Turning lights off and on uses more energy than just leaving them on.

Not true. Turning off lights definitely reduces energy use. Turn off LED and incandescent bulbs every time you leave the room. The situation is a little different with compact fluorescent bulbs (CFLs). Turning them off does save energy but can shorten the life of the bulb. The rule of thumb for CFLs is to turn them off any time they won’t be used for 15 minutes or more.

Replacing your old windows with newer, efficient ones won’t cut your energy costs in half, but it could reduce your costs by about 10 percent. Photo by Michael Mroczek.

2Claim #2
Replacing old windows with new, more efficient ones can cut energy use in half.

This is not accurate. While replacing inefficient windows with new, energy efficient windows can cut the heat loss through windows in half (or more), windows typically account for only about 25 to 30 percent of your space heating costs. The amount of energy you use for heating and cooling is likely one third to one half of your total energy use, so replacing your old windows might only reduce your total energy costs by about 10 percent. When you consider the high cost of new windows, you may not recoup your investment for 15 or 20 years, or even longer.

3Claim #3
Burning wood in a fireplace should save on heating costs.

Possibly, but certain conditions need to be met. The wood should be dry and burned efficiently in a properly installed, properly placed, high‑efficiency wood stove or fireplace insert. Otherwise, it’s likely you’ll lose as much heat through your chimney as you’re distributing throughout the house.

4Claim #4
Using the dishwasher is just as efficient as washing dishes by hand.

Yes — in fact, it’s usually more efficient! Properly used dishwashers actually use less water while doing a better job, and as a bonus, they will save you more than 200 hours of handwashing a year. For maximum savings, set your water heater to about 120 degrees and use the most efficient wash/dry settings.

5Claim #5
It’s better to heat individual rooms with an electric space heater and keep the doors closed to trap the heat.

It’s possible to save money with an electric space heater if you use it only a few hours a day and reduce your home’s thermostat setting by a couple degrees. Space heaters can cause fires, so they need to be used wisely and should never be left unattended. Which brings us to the next claim …

6Claim #6
Close vents in rooms that aren’t used.

Most experts advise against this because closing supply registers forces your furnace or A/C unit to work harder. They advise keeping all your vents and doors open. If your system supplies too much heat to some rooms and too little to other rooms, you should talk to a heating and air conditioning professional about modifying your ductwork.

7Claim #7
The age of a home determines how energy efficient it is.

Not necessarily. Newer homes tend to be more efficient because energy codes have improved, but every home can have hidden energy issues, no matter its age. If you want to evaluate the efficiency of your home, it’s best to schedule an energy audit with a professional recommended by your local electric cooperative.