Energy saving or resource wasting?

[GrasB]

As I reported yet another florescent tube blown in our new building a thought occurred to me. In this building I find a tube having blown once every 2 weeks or so (I'm one of the first in the door so end up catching this kind of thing), every other building I hardly ever report a tube blown, maybe once every 2 months. The difference is the new building has auto-sensors which turn the lights on when you walk down the corridor & then turn the lights off after 5 min, for energy saving reasons. The thing is this causes the lights to be turning on & off almost all day as people walk through the building. All the other building have a 30 timer or are normal switches.

So does having the lights turn off after 5 min actually save more energy/resources than it created by eating up florescent tubes at the rate of at least 1 every 2 weeks? Has 'energy saving' gone too far & so we're using more resources than we're saving?

 

[Arch]

I did see a Mythbusters test where they found out that unless you were only going to be out of the room for less than a second, it wasn't worth turning flourescents off, because the start up power was more than the power used by the light for that time.

I can't remember if they said it ate the tubes up quicker turning them on and off though.

Stuff like this certainly isn't always well thought out. I used to work in an Eco business centre which had toilets upstairs that had a frosted skylight, providing natural, if less than bright light - perfectly fine for the purpose provided. But they also had lights, for when it was dark, and these were automatic, coming on when you went in, and turning off a few moments after you left. So I'd often go in, not needing any extra light, then have the light come on, and I couldn't turn it off as I left. I can see that in a big building you'll struggle to get everyone to turn lights off, hence the automatic bit, but why not add a light sensor so that they don't come on when the cubicle is perfectly light enough?

Like any new idea, it takes time for the right ideas to come to the surface. The Environment Centre I work at now was entirely built with eco in mind, but has plenty of features which have been revealed to be unsuitable for the level of use it gets, although on paper they work at a household level. They don't tend to be wasteful, but they make life difficult at times. Now, with experience, we'd know what compromises would work best.

 

[User482]

The timers are usually adjustable - try setting it to 15 minutes and see if it makes a difference. That said, I'm not aware of blown tubes being a problem in any of our buildings with motion sensors, so it could be an electrical fault.

 

[Night Train]

I reckon if the tubes are failing so frequently it would be a loose connection issue causing the lamps to fail through the supply being intermittent.
They shouldn't be significantly affected by being on sensors or timers, though the sensors could be failing if they are not suitable to inductive loads.

 

[GrasB]

I don't have any control over the building I was more just making an observation. Also I don't know a huge amount about this but I was under the impression that turning a fluorescent tube on was very stressful for it. Therefore constantly turning on & off would dramatically shorten the life of the tube. The when the new building was being built our existing building had motion sensors & new lights corridor lights retrofitted at the same time but the duration was set to 30min not 5min in the new building. It's odd that the building which has the lights set for 5 min is constantly eating 'tubes but the building set to 30 min hardly uses tubes at all.

NT, it's the typical 'the tube has gone' flicker 1 or 2 times then fizzle out. If you look at the tubes they're black at both ends. My guess is there's about 30 tubes in the new building & about 45 tubes in the old building.

Arch, <sarc>it's a great design this building</sarc>. The offices get loads of light from huge windows etc. The issue is there are only small skylights to let light into the corridor on the top floor but the ground floor only has a 15cm wide strip of frosted glass running down the middle of the ceiling to let light in down stairs. In blazing sun it gets bright enough upstairs not to need lights but it's never bright in the lower corridor. Oh din't get me started on the eco toilets which use rain water for flushing... we all love the smell of stagnated water after flushing

 

[biggs682]

theres loads of offices around who leave lights on all 24/7 which seems a total waste . the office i work in is glass sided and most days you could work with no lights on but they have to be for health & safety !

 

[Browser]

Get them to ditch the fluorescents and fit LED lighting, I believe it to be far more robust and energy efficient. As far as I know and have read/heard, fluorescents don't like being switched on and off a lot. We've dimmable fluorescents in the CCR at work and they cost a bloody fortune as (a) they don't seem to like being dimmed and (b) are getting old, so the expensive digital ballasts that allow them to work are starting to fail and are £50 a pop.

 

[Rickshaw Phil]

Electrics are not my speciality, (my electrician cousin could answer better) but from experience, my nan had a security light setup which was fitted with a pair of florescent bulbs. These bulbs would burn out regularly at around six months old while the exact same make/model lasted years in our lounge at home.

From this I'd be inclined to say they are not suited to the type of duty the OP is talking about.

 

[Paul J]

Could be cheap unbranded lamps being used but most large buildings use planned maintenance to change them so that single visits to replace only one tube, as this works out expensive due to labour.

If you have ever worked under or installed LED lighting it's a love hate relationship. I don't like them and have installed whole factories with LED lighting.

 

[Arch]

Oh din't get me started on the eco toilets which use rain water for flushing... we all love the smell of stagnated water after flushing

I have no sympathy for you there at all. Using fresh clean potable water to flush toilets is a complete waste of resources.The toilets at the eco centre I used to work at were also rainwater flushed, and never smelt at all.

Also, at my current work we have compost toilets, and it's my job to empty them. So

 

[slowmotion]

Frequent on-off cycles certainty reduce the life of compact flourescent "energy saving" bulbs. They sometimes claim a life of 10,000 hours, about ten times that a tungsten filament bulb, but the reality is somewhat different when they are short cycled. I dimly recall some piece of official advice for people to leave them on if they would otherwise be switched off and on again within about thirty minutes. Like all official advice, that's probably rubbish too...

 

[PBancroft]

[QUOTE 1839254, member: 9609"]The heating up cooling down causes the seal at the ends of the tubes to break down, and will shorten the life - If you left these things on continuously they would keep going for decades.[/quote]

Decades you say?

I think another problem is because something is perceived as "energy saving" people feel justified in leaving it turned on for longer than they would do normally. I know of at least a couple of friends who have bemoaned the energy saving bulbs which aren't immediately as bright as the old style... so they turn them on a while before they know they're going to need them, and then just leave them on for the next time they need them (they aren't really that dim - the bulbs that is, I'm not so sure about the friends).

 

[GrasB]

I have no sympathy for you there at all. Using fresh clean potable water to flush toilets is a complete waste of resources.The toilets at the eco centre I used to work at were also rainwater flushed, and never smelt at all.

I told you not to get me started... we're a world leading university department yet we have a building which has toilets that stink all the time, the building in boiling hot in summer (>35C inside with outside air temps at 20-25C) & freezing in winter (just about getting up to 14C inside with the heating on maximum when it's around 0C outside) because someone couldn't be bothered to work out the design properly. It's an embarrassment to the department. We can't locate visitors in the building, professors refuse to have offices in the building....

 

[Andrew_Culture]

I used to have a record shop and after a long period of leaving the lights on at night we switched them off to save power, and were immediately burgled.

What does this anecdote prove? fark all