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LED Lighting

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  • 31-07-2015 3:02pm
    #1
    Registered Users Posts: 7


    I am trying to find out the cost advantages of LED over CFL in terms of both electricity and maintenance.
    I have been living in an apartment development for a number of years and they are still using cfl lights that are on for a lot of the day. The bulbs go, and often the housing units blow out too. This means that there are always parts being replaced and that either the maintenance man or an electrician has to be used.
    The electricity bill is running at over a 100k a per year, which granted uses other things, but I bet a large chunk of it is in relation to lighting.
    I have been pushing to get LED lights with motion and day/night sensors in, and need to know if the cost savings would result in a relatively short pay back period. Does anyone have any knowledge of the companies doing this sort of thing, so that I can raise the issue at the AGM?
    What I would like to do is to get a retrofit with LED. For some our board have still not made the switch over. If I had good information on the cost/benefits and recoupment period in relation to electricity and maintenance savings, I would be in a better position to make this conversation at the next AGM and have it on the agenda.


Comments

  • Moderators, Technology & Internet Moderators Posts: 11,011 Mod ✭✭✭✭yoyo




  • Moderators, Home & Garden Moderators, Technology & Internet Moderators Posts: 10,952 Mod ✭✭✭✭Stoner


    Well it would depend on the fittings you have for real saving comparasons how often are they switched electronic or standard ballasts etc . The wattage comparison is simple enough count all the fitting you have compare the equivalent led lamp , work out how long they are on for and do a hw/hr saving check.

    Movement sensors are very good. You Might need fittings with that build in though for retro fitting.
    That is another saving considerable and could half the lighting bill combine it with a daylight sensor as an override too.

    But you'd have to take an educated guess on the occupancy rate for switching.

    It's easy enough to do it but to do it but I'd be careful nailing your opinions on saving to the mast. Led lamps do not last as long as they claim, you might get the lamp replaced foc but Labour is still an issue


  • Registered Users Posts: 23,375 ✭✭✭✭ted1


    Does the 100k include the usage by the apartments? How many apartments are there ? For lighting / lifts and possible heating of common areas that's high.

    With LED there is no real need for motion sensors , they just add to the costs. Lux sensors will do, also bear in mind motion sensors aren't great for general comfort or security. People can lurk in the dark and won't be picked up by the motion sensors


  • Moderators, Home & Garden Moderators, Technology & Internet Moderators Posts: 10,952 Mod ✭✭✭✭Stoner


    I was assuming that the lighting in this case was the landlord core lighting not the domestic units. If that's the case pirs with photo override will produce savings.

    Leds compared to fluorescent lighting is a saving but apartment blocks with the core lights on all the time while it's dark (there are plenty around) are crying out for floor by floor pir sensors that switch the lights off after 10 minutes.

    Many apartment blocks have had these retro fitted or designed in. All the lights turned on fron 5 pm in the evening till 8 am in the morning is a waste of energy.

    I agree they are not great for the domestic zones. But they should be in the cores and the car parks.


  • Registered Users Posts: 23,375 ✭✭✭✭ted1


    Stoner wrote: »
    I was assuming that the lighting in this case was the landlord core lighting not the domestic units. If that's the case pirs with photo override will produce savings.

    Leds compared to fluorescent lighting is a saving but apartment blocks with the core lights on all the time while it's dark (there are plenty around) are crying out for floor by floor pir sensors that switch the lights off after 10 minutes.

    Many apartment blocks have had these retro fitted or designed in. All the lights turned on fron 5 pm in the evening till 8 am in the morning is a waste of energy.

    I agree they are not great for the domestic zones. But they should be in the cores and the car parks.

    A 10W LED left on for 8 hours a day 365 days a year costs about 4.5 euros a year.
    To supply and fit a PIR say cists 20 euro. So you looking at roughly 5 year payback providing you don't use any lighting.

    I've often seen quotes of 40 euro to supply and fit PIRs so that's 10 years payback providing no lights at all are used.

    For car parks inductive lighting works great.


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  • Moderators, Home & Garden Moderators, Technology & Internet Moderators Posts: 10,952 Mod ✭✭✭✭Stoner


    ted1 wrote:
    A 10W LED left on for 8 hours a day 365 days a year costs about 4.5 euros a year. To supply and fit a PIR say cists 20 euro. So you looking at roughly 5 year payback providing you don't use any lighting.

    Fair point

    PIRs per floor imo is the way to go and the total power usage of a thorn club 28 W 2D is 36W when you have powered the control gear and the lamp.

    If you were limited to like for like fittings in LED something in the rough equivalent of an 18W Led in a fitting of total power consumption of about 20-22W.
    I've yet to see a 10W led fitting replace a 2D (28)consuming 36W. People put them in and don't take the lamp loss / lumen maintenance factor into consideration at this is high in many cases with leds, up to 50% in the case of some Philips master LEDs. So the initial light is reasonable compared to possibly and end of life fluorescent. Then you are into poor light on stairs insurance etc. I'd simulate the light output on relux or dialux as you know is takes about 15 minutes. If the fitting you intend to use has no dialux or relux files I'd avoid it as its performance cant be simulated and most likely it's been through changes without output checks lamp life ,glare or output

    Many apartment cores have two of these per landing one ordinary one emergency. There are two landings per floor , the main and the half so that's four fittings per floor.

    So 4* 21W = 104W switched per pir, if on average if we had 10 hours use per night if we could achieve switching them off for 60% of the time it would be worth it. But it depends on the building that neither of us have seen

    I take your point that one on one is not worth it.

    If it was a new design there are some nice fittings to take the place of 2 landing fittings, a 33W led fitting . But they are pricey and all that comes into play.

    I've seen 18W led 2D club equivalent fittings with built in PIRS for Euro 40 .
    We tested one and I'd stay a mile away form them.


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