Viewing 12 posts - 1 through 12 (of 12 total)
  • Halogen downlighters and smoke alarms
  • sharkbait
    Free Member

    Other than the fact that they use a load of ‘leccy I’ve now got two more reasons to change ours to LED’s:

    1) Chap I ride with was having tea when the house alarm went off, then heard water running upstairs so went to investigate. The water was running out of the loft hatch and was warm so he lifted the hatch to see what had happened (expecting to see a burst pipe) only to find towering inferno.
    The heat had melted the header tank and the water luckily stopped the fire spreading too much. Firebrigade called and they put it out.
    If it had happened at night the fire would have spread and the ceiling would have fallen in on their bed.
    Cause: heat from halogen downlighter near woodwork eventually causing it to catch fire.

    2) Same as above but an other friend who had been out for the night (as a family), came back to find their converted farmhouse had been converted once again to a pile of rubble 😯
    Cause: heat from halogen downlighters or mice eating cables

    Lesson learnt: put a smoke alarm in the loft and get rid of halogen bulbs going into the roofspace. Saves money and maybe even lives.

    FunkyDunc
    Free Member

    I thought you were supposed to mount them in a firebox thingy so they cant ignite stuff around them.

    I was amazed how scorched the bulbs and cables etc were when I changed from Halogen to LED.

    bensales
    Free Member

    Fireboxes aren’t meant to prevent the light causing a fire, they’re meant to preserve the fire integrity of the ceiling you’ve cut a hole in to mount a downlighter.

    Observe the correct distance requirements for a downlighter and they’re fine.

    bruneep
    Full Member

    Observe the correct distance requirements for a downlighter and they’re fine

    and fit a smoke alarm and test it regularly.

    Phil_H
    Full Member

    Retrofit LEDs get hot too.

    sharkbait
    Free Member

    Retrofit LEDs get hot too.

    Err, mine don’t.

    SprocketJockey
    Free Member

    Windsor Castle fire was caused by a halogen light… in this case a spot left by a decorator caught some curtains alight:

    Link to the ESC leaflet which we give out to the trade here with some advice which may be useful:

    http://www.dsfire.gov.uk/YourSafety/documents/ESCDownlighterLeaflet-Trade.pdf

    Flaperon
    Full Member

    Other possibility is that they fitted halogen lamps with dichroic reflectors, which dump the heat from the light into the roof space.

    LEDs get warm, but since they consume at maximum about 8W (with about 40% efficiency), a room with 10 downlighters is dumping *at most* 50W into the roof space. With 50W halogens and 4% efficiency, 480W is being put into the roof space.

    Not hard to see why they catch fire. Frankly, 50W halogens should be banned entirely IMHO.

    lerk
    Free Member

    50w halogens are crap, but they are cheap…

    LED’s are superb, but good ones are: A) hard to come by and B) very expensive.

    Unfortunately as with most of the latest greatest things, the market is flooded with masses of blue tinted dross that puts out stupidly low amounts of light for their unbelievably short life span…

    What is required is for industrial type fittings to be taken up by the likes of B&Q to tart them up and make them acceptable to those who walk among us without wedding tackle. Then, we may just be able to achieve usable levels of illumination and lifespan – as long as people realise that the lower power consumption means that a £100 light fitting is actually very good value!

    oldgit
    Free Member

    Heat forward lamps should be used in those fittings.

    Correct lamps fitted.
    Lamps wear.
    Customer buys a lamp that fits from Tescos.
    Lamp isn’t heat forward.
    Heat goes up and out the vents.
    Wires melt because you bought the cheap ones that don’t have heat resistant braiding fitted over them.
    Fire starts.
    A certain company I won’t deal had to spend thousands in compensation because they cut corners on the manufacturing.

    And most LED get very hot, hence the massive heat sinks.

    Flaperon
    Full Member

    And most LED get very hot, hence the massive heat sinks.

    Only if they’re being over-driven (ie, as bike lights or some el-cheapo Chinese knock-offs).

    The reason LEDs have massive heatsinks is because lamp life is reduced exponentially as their lamp temperature (or, specifically, the junction temp) increases. 50C can be the difference between 10,000 hours life and 1,000,000 hours. It’s no problem if the heatsink is running at 50-60C because it’s still only dumping 5W into the environment.

    FunkyDunc
    Free Member

    The LED 6w Ive got get barely warm even when they have been on for 1hr

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