I'm arguing with my roommate over how to save electricity, re: lights.

[Quantess]

She thinks that it wastes electricity to turn lights on and off, unless you leave them off for a couple of hours or more. I say, if you are leaving the room for 10 or 15 minutes or more, it's better to turn the lights off.

The two lights in question are the long, fluorescent types. She says that because they are so long, just turning them on draws a lot of energy, so it's better to leave them on.

She thought I didn't understand her explanation. I said "no, I understand the reasoning perfectly, but it just isn't true!"

I might be inclined to just let her win the argument because it isn't a big deal to me, but SHE is the one so obsessed with keeping the electric bill down.

Who is right?

[SpiralHawk]

1. Tell her: on is on

off is off.

[brooklyn297]

19. this

[sam11111]

2. 22% cheaper electric -- Municipalize ur utility

Cuts out the profit markup by corporatists.

[MADem]

6. Completely unhelpful to this person's situation. That takes years. nt

[Quantess]

10. Thanks anyway.

:) Welcome to DU!

[bananas]

3. If the government says so, it must be true...

Not sure if this is about CFL's or long tubular flourescents:

http://www.energysavers.gov/your_home/lighting_daylighting/index.cfm/mytopic=12280

<snip>

The cost effectiveness of turning fluorescent lights off to conserve energy is a bit more complicated. For most areas of the United States, a general rule-of-thumb for when to turn off a fluorescent light is if you leave a room for more than 15 minutes, it is probably more cost effective to turn the light off. Or in other words, if you leave the room for only up to 15 minutes, it will generally be more cost effective to leave the light(s) on. In areas where electric rates are high and/or during peak demand periods, this period may be as low as 5 minutes.

Fluorescent lights are more expensive to buy, and their operating life is more affected by the number of times they are switched on and off, relative to incandescent lights. Therefore, it is a cost trade-off between saving energy and money by turning a light off "frequently" and having to replace the bulbs "more" frequently. This is because the reduction in usable lamp life due to frequent on/off switching will probably be greater than the benefit of extending the useful life of the bulb from reduced use. By frequent we mean turning the light off and on many times during the day.

<snip>

I think this is about CFL's:

http://www.scientificamerican.com/article.cfm?id=turn-fluorescent-lights-off-when-you-leave-room

<snip>

A simple rule of thumb that balances both concerns is to shut off fluorescents if you’re planning to leave a room for more than five minutes, according to Francis Rubinstein, a staff scientist in the Building Technologies Department at Lawrence Berkeley National Laboratory's Environmental Energy Technologies Division. Mary Beth Gotti, manager of the GE Lighting & Electrical Institute in Cleveland, agrees. For all practical purposes, "it almost always makes sense to turn the lights off," Gotti says. "From an environmental standpoint, the best way to save energy is to turn off the things that you're not using."

Rubinstein notes that, even for fluorescents, the cost of electricity over a bulb's lifetime far outpaces the cost of the bulb itself. "Even if you switch on and off a fluorescent light frequently," he says, "the slight reduction in lamp life is a small effect relative to the energy savings you accomplish by being a good citizen." Gotti adds that the reduction in lamp life from frequent on-and-off switching can often be counterbalanced by the extension of "calendar life"—the actual passage of time between lightbulb replacements—that results from using the bulb for fewer hours.

<snip>

[Quantess]

4. Thanks!

I'll definitely read it.

[alphafemale]

5. As to the post above it is more related to bulb life.

Those long florescent bulbs can be incredibly expensive and the energy used to keep them on is negligible. It did used to take a couple of minutes for a florescent light to be fully "On." But I haven't seen a flickering/dim "warming up" florescent light in ages.

[Quantess]

11. One of the light bulbs buzzes and flickers for the first 5 or 10 seconds.

I avoid turning that one on, at all. It's inside an old, handcrafted, hanging lamp, if that makes a difference.

[Confusious]

15. The CFLs do that when they get older

takes a little while to get to full brightness.

[MADem]

7. You are right, mostly as the article someone kindly posted notes. But here is a way to

save even more electricity--convert those flourescent lights to LEDs...

http://www.ehow.com/how_5600973_convert-fluorescent-led.html

[Tesha]

24. Actually, modern "T5" long fluorescents are currently more-efficient than most LEDs and *MUCH* more

affordable. And this probably won't change for a few years.

Even more-widely available "T8" fluorescents are about as efficient
as LEDs and much more affordable and much more widely available
than "T5" fluorescents.

Tesha

[hlthe2b]

8. I had a roommate once that was so obsessive about this...

that they wouldn't even leave on a low wattage light or two--or even a nightlight in pitch dark hallways or bathrooms. I think that the $$$$ of medical deductibles she eventually paid after she tripped over her own cat and broke her ankle, finally convinced her. There is that old adage, "A Penny Wise, A Pound Foolish" that one has to keep in mind...

[txlibdem]

9. Looks like the concensus is that you are right about turning them off

But don't gloat to your roomie too much.

Here's a more technical, yet still easily understood explanation:

This is an urban myth that has persisted for many years. Here's what you should do...

You should turn off your fluorescent lamps if the space is not going to be occupied for more than a few minutes (3-5 minues is a good rule of thumb). The modern electronic ballast and T8/T5 lamp combination do draw a higher level of current during startup, but it only lasts for a fraction of a second, which is negligible compared to normal current requirements of the lamps.

Leaving fluorescent lights on when you leave an area is one of those myths from the '70s that has somehow survived to this date. In fact, occupancy sensors are routinely used with fluorescent fixtures to turn the lights off when no one is in a room.

A bigger concern here may be the impact of frequent on/off cycles on the lamp's life. This does shorten the lamp life somewhat. However, leaving the lights on all the time also reduces the lamp life. In fact, it has been shown that even though occupancy sensors reduce the lamp life as measured in total hours, they actually extend the calender of the lamps because the lamps operate only during those hours that are needed.

http://www.consumerenergycenter.org/myths/fluorescent_lights.html

As a denizen of the 70s I still had that "understanding" in my head till I read the responses (plus a few googled articles). Thanks for posting this question!!!

PS, one of the responses suggested you should modify the lights to LED. Don't do any changes if you live in a dorm - you will be held responsible (not pleasant). If you are renting an off-campus place then ask the landlord so they can get an electrician to replace the fixture with an LED fixture (if they say no then... sorry).

[Quantess]

12. Wow, you are so perceptive! 2 good guesses.

I'm renting a room from an older lady while I'm attending school. I'm a bit younger than a "denizen of the 70s", but she's a denizen of the 60s and 70s.

I'll look into getting an LED fixture, costs, feasibility, etc. I am in Europe currently so I don't really know what rules apply. I would imagine they are even more "green" here than the USA, but, this is an old apartment.

[txlibdem]

14. If I was young and / or in your position

I would look into immigrating to Europe (but not the UK, it's moving too fast toward the right).

Years ago, I looked into immigrating to Canada. They will accept immigrants if they have certain college degrees. They will also accept you if you have $50,000 or more in liquid assets and wish to start a business in Canada. Well, I have no degree and I'm about $49,995 short of meeting the cash requirement so there goes that idea.

And being disabled isn't a plus on my application either. One of these days the USA will have shifted so far to the right that some country will begin accepting refugees from the USA. I will go there then.

[Confusious]

16. Austrialia has the same requirements. nt

[Historic NY]

13. I remember using a military library that had fluorescent tubes on motion timers...

they would all go off after 15 minutes and they made one heck of a racket all snapping on again. It seemed more wasteful to me. The entire stack was all wired together.

[miyazaki]

17. She's ridiculous. Does she keep her car running all night

so its nice and warmed up in the morning? ha.

[AtheistCrusader]

18. If it's a modern electronic ballast, turn it off.

Older crap, larger window of 'draw' at initial start up to offset.

The newer ballasts are awesome. I turn them off and on all day long. No biggie.

[Name removed]

20. Deleted message

Message removed by moderator. Click here to review the message board rules.

[NMDemDist2]

21. she'd save more by putting computers and TVs on a power strip and turning them off

when not in use

the new TVs especially are power hog ghosts

there's a thread somewhere in DU Groups talking about the power savings with this

[Quantess]

22. Where can I find this mysterious thread?

Yes I have heard about power hog ghosts.
But she is a stubborn older lady, and the main focus centers around lights being turned off and on. For me, my rent is fixed, so I'm trying to be helpful. But I sense she would rather be frugal than win an argument. Although, she is hellbent on winning this argument, also.

Please note, this is occurring in Sweden, with an older Swedish lady who speaks no english at all.

[txlibdem]

23. Sometimes a tactical retreat is the best option when dealing with an opponent who is well-dug-in

Sometimes it's best to lose a battle in order to win the war. And sometimes it's just best to take a long term stance, taking an occasional opportunity to educate the opponent little by little.

It is also possible that your fluorescent lights are indeed the old type that waste a lot of energy just starting up. If that's the case, it may be more important to have harmony and give a little ground on this issue.

[dairack]

25. Turning off the Lights

Turning off the lights is absolutely one of the simplest ways to decrease your impact on the environment and save money everyday.

Check out this video of Ken Jeong (NBC's Community) as he speaks of how you can save money and the environment by simply turning off the lights. This video is part of NBCUniversal's environmental initiative "Green is Universal."

http://video.greenisuniversal.com/fe...jeong/v1321547

I'm helping NBCUniversal spread the word about their "Green is Universal" campaign, so let me know if anyone has questions.

---
Derek