Hi
I have just had my ceiling plastered. I now need to drill six holes for downlighters. I have pre-positioned the cables and know roughly where I want to drill.
This is the pattern
x x x
x x x
x x x
Has anyone got any good tips on how to mark the pattern out to ensure the the rectangle is line with the walls and the lights are in a straight line. I have thought about using string to get the lines straight, but hadn't thought how to get the right angle to the walls.
good time for a laser spirit level with right angle line generator, I would have no hesitation in reccommending you treat yourself to one.
mrcheerful
If you're painting the ceiling and don't mind making pencil marks, then a bit of Euclidian geometry using a drawing pin & a length of string with a pencil tied to the end will get you the results you need at minimal cost.
I used drawing pins and thin kite string - and measured so the lines were parallel with the walls.
Do you know exactly where your ceiling joists are? If you are using LV halogen downlighters (and it probably applies to other types too) you have to ensure that no part of a lamp is less than a certain distance (50mm?) from a joist. This can cramp your style a bit when you come to position them - particularly if you have an L-shaped room with some joists perpendicular to others, as I have!
Yes, don't drill nine holes if you've only got six lights ;-)
Thanks. I said six, but meant 9!
Fortunately I know exactly where the joists are, so should be able to position the lights in the middle. I am using mains halogen lights.
Take them back and get a refund.
If you absolutely must have halogen (and I don't see why myself), then at least fit LV ones. As well as an astronomoical electricity bill and the death of several million Bangladeshis on your conscience, you'll be replacing several bulbs a week at great financial and environmental cost.
Christian.
How are 50W LV bulbs more efficient than 50W mains?
can you elaborate on the 'death of several million Bangladeshis' bit ?
RT
Basically, a 230V halogen requires a thin filament to create enough resistance to keep the power down to the required level. Unfortunately, this causes a few problems, such as not being able to dissipate the heat and having enough filament material to make the bulb last. This results in bulbs that last for a much shorter period than an equivalent power LV bulb.
There are other effects too, such as the tightness of the beam. As people often inappropriately use spotlights for general lighting, the fact that there is no leakage is very inefficient, as far more direct down beams are required. Most lighting makes use of wall or ceiling surfaces to bounce and diffuse the light, which doesn't happen with spots. This means that far more actual light power is required than traditional bulbs, even though halogens technically are more efficient than traditional bulbs.
Other inefficiencies include having to remove insulation to accommodate the large heating component of the wasted energy in the ceiling.
Your proposed lighting system uses 450W of lighting for a room that could be lit with greater efficacy with 2 100W light bulbs (200W) or 2 25W CFL bulbs (50W).
Christian.
Starvation or drowning as sea levels rise due to arrogant and unnecessary use of carbon based fuels by western society.
Christian.
Might take a week or two to happen then.
hasn't it been that way in bangladesh for centuries, being prone to flooding on a grand scale for as long as records began and probably longer ?
don't get me wrong, the 'west' /is/ power drunk in more ways than one but it seems a bit odd to equate the use of mains halogen lights with the ongoing 'death of several million Bangladeshis'
what about the energy required to manufacture 12V transformers in relation to the manufacture of straight forward 240V bulbs, halogen or not ?
shirley it's more energy efficient to use 240V halogen and skip use of a transformer which was probably made in a massive old tech factory by 12 year olds in theR.O.C with scant to zero regard for any environmental or humanitarian concerns ?
makes you think, dunnit ?
RT
Because short fat 12v filaments are mechanically stronger than long thin
240v ones, it also means that you can run 12v filaments hotter - resulting in much more of the input energy being converted into visible light rather than infra-red - and giving a whiter light, to boot.
I wondered about that too ...
But when I did a bit of googling for "halogen bangladesh" I didn't seem to come up with results any more significant than I'd expect from random searches like "halogen aardvark" or "bangaldesh brylcreem"
I half expected to see horror stories about how 12 year-old Bangladeshi children were sent blindfolded down rickety mine shafts to suck up deadly bromine through straws, just so we can have lightbulbs!
It's changing all those individual decisions lower down that is the only way to make huge changes on a global scale.
The bulbs would probably be made in a worse factory and you'll need many times more of those mains halogens than the LV types.
Christian.
probably ? imaginary more like.
oh dear.
but what about the plastics and the potting compound and the ....
/gives up.
RT
Seriously, mains halogens last a fraction of the time of an LV bulb and cost twice as much each. The transformer will last a lifetime and will easily save money over an extended period compared to a mains based solution.
Christian.
Thanks for the answers Christian and Set.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.