Energy Myth Busters
Don’t be deceived by common myths about saving energy. At work, someone will say, “I heard that turning your office lights on and off often uses more electricity than just leaving them on all day”. And other people, trying to be helpful, will tell you that you should leave your computer running 24/7. True or false? Below are some common energy myth busters to help you save money along with an explanation why the myth is false – or sometimes just partially true.
If you have a myth to share or wonder if an idea you’ve heard about saving energy is a myth or the truth, let me know by leaving a comment. If it can benefit readers, I’ll add it to the list below.
Here are some energy myths:
Fluorescent lights make noise
You’ve probably heard a buzzing noise from fluorescent lights in an office. That noise isn’t coming from the lamp, it’s coming from a failing ballast. Neither ballasts or lamps make a noticeable noise when operating properly. The same goes for compact fluorescent bulbs. If you hear one that makes noise, it needs replacing.
I’ll use less energy to boil water if I start with hot water from the tap
It uses the same amount of energy to boil water regardless of where the energy comes from. Hot water from the tap is heated by the water heater and energy is lost in the pipes between the water heater and the faucet. The cost of the energy can vary greatly depending on appliance efficiency and whether you are heating it with electricity or gas, but the energy needed to make the water boil is the same.
Unless you have solar heated water, for most people it is least expensive to boil water starting with cold tap water. This is especially true if you have an electric water heater since the hot water they produce costs more than from gas water heaters.
To save energy, use a covered pot and boil only enough water to meet your needs. Less water will boil faster and use less energy.
It uses less energy to keep my house a constant temperature than to let it cool down and have to heat it back up when I need it warm
It takes less energy to warm up a cold room to 70F than to maintain it at a constant temperature of 70F for an extended time, such as overnight or while at work during the day.
The less difference there is between outside temperature and inside temperature, the less energy is used. You’ll save energy every hour you can reduce the number of degrees difference between outside and inside temperatures. So letting your house cool down for as long as possible will save energy. Programmable thermostats save money by automating this so you can live life rather than adjusting a thermostat all the time.
This concept of reducing the temperature differential between outside and inside to save energy applies to both heating and cooling. Turn off heating and cooling as long as possible when you’re not home.
It’s more energy efficient and better for my computer to leave it running when not in use
You will save energy anytime you turn the computer off. And you will extend the life of the computer by turning it off. Heat is enemy number one for electronic devices. Anytime you can reduce heat you extend life. Another factor, one that is commonly overlooked, is the collection of dust on cooling components inside a computer, especially cooling fins on heat sinks. The more a computer is run, the more dust collects inside the box, reducing the cooling capacity. The increased heat can be harmful to components. This is why computers should be cleaned periodically.
Computers should be operated similarly to lights. If you aren’t planning to use a computer for a while, turn it off. The best solution is to set the power feature in the operating system to put the computer to sleep after a pre-determined number of minutes. Find the number of minutes that fits your computing needs. Some people can set the machine to go to sleep after 15 minutes of inactivity, and some find 60 minutes necessary. The nice thing about this feature is that you’ll never have to turn the computer off again – just use it as needed knowing it will shut down by itself after you’re done.
Read up on all the different levels of “sleep” for computers. Some levels save energy but maintain power to memory for quick recovery when you return. Hibernation uses the least energy and should be used whenever possible. When a computer “hibernates” it saves everything in memory to the hard drive or solid state drive and then shuts down nearly all components. This is the best state when you’re not planning to use the computer for many hours, like overnight. Also, hibernating computers are not subject to losing data if an electrical power outage occurs.
Leaving a light on uses less energy than turning it off and on several times
Leaving an incandescent or a fluorescent lamp on uses more energy than turning it off and on several times. The slight inrush of energy when a lamp is turned on is very small compared to the electricity used when you let it burn for a while.
One thing to keep in mind is that the life of a fluorescent lamp is shortened by numerous on/off cycles. This is minimized by using a program start ballast instead of a rapid start or instant-on ballast. Program start ballasts cause a slight delay when a lamp is turned on. The starting current is controlled and this increases the life of the lamp. To reduce the effect of on/off cycles on a fluorescent lamp’s life while also minimizing energy usage requires a compromise, so it is best to turn it on and off in moderation.
Recommendation: Turn lights off if you don’t plan to use them for 15 minutes or more. Better yet, connect lights to an occupancy sensor set to 15 minutes.
Setting my air-conditioner thermostat to its lowest setting will cool the room faster
The lower setting will not cool the room any faster. Most air conditioners run at a constant speed and are either on or off. They simply turn on at full speed and run until the set point on the thermostat is reached and then turn off. The position of the thermostat dial doesn’t affect the fan speed or the temperature of the supply air.
High-efficiency air conditioning systems today are taking advantage of variable speed motors for both compressors and fans. These units can be an exception to the above statement. Moving the dial just enough to make the unit come on might only engage one of two compressors and might turn the fan on at a slower speed because the system is smart enough to realize it only has to lower the temperature by 1 or 2 degrees. You’ll know if you have a variable speed fan because the fan will usually run more hours but at a very low speed. It is both quiet and efficient.
Setting my heating thermostat to its highest setting will warm the room faster
The higher setting will not heat the room any faster. Most furnaces run at a constant speed and are either on or off. They simply turn on at full speed and run until the set point on the thermostat is reached and then turn off. The position of the thermostat dial doesn’t affect the fan speed or the temperature of the supply air.
High-efficiency heating systems today are taking advantage of variable speed motors to run fans. These units can be an exception to the above statement. Moving the dial just enough to make the unit come on might turn the fan on at a slower speed because the system is smart enough to realize it only has to raise the temperature by 1 or 2 degrees. You’ll know if you have a variable speed fan because the fan will usually run more hours but at a very low speed. It is both quiet and efficient.