halogen recessed lighting calculations

Discussion in 'Electrical Forum discussion & Blog' started by dabiz7, May 28, 2008.

  1. dabiz7

    dabiz7 New Member

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    I am wanting to replace some regular ceiling incandescent light fixtures with recessed halogen lighting. Is there a good place or source of info on how to calculate how many halogen light fixtures I can run on the existing light circuit beofre I have to add another circuit?
  2. Billy_Bob

    Billy_Bob In the Trades

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  3. jimbo

    jimbo Plumber

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    Halogen is an incandescent fixture. You would be limited by however many fixtures ( watts ) you may have now, and the actual wires and breakers. 15 amps is 1800 watts, and you would not want to load a circuit right to the hilt. Halogen incandescent does give more lumens per watt of electricity than tungsten incandescent. That is why halogen is condsidered a step in the energy saver direction. But halogens run very hot, so you have that issue to deal with. And why not go right to fluorescent recessed fixtures, if your goal is more light and less energy?
  4. hj

    hj Moderator & Master Plumber Staff Member

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    lighting

    You may also have to give consideration to the cone of light the recessed fixture gives to determine how many and where to put them.
  5. dabiz7

    dabiz7 New Member

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    wow! thanks for the responses

    I really like the look of the recessed lighting, so am using the hall light as an easy starting project to see how it goes. I currently have a single three bulb fixture in the center of a 20 ft hallway. I want to replace this single fixture with three or four smaller recessed lighs in this same hallway. I haven't really looked at the different lights yet to see which I like better, halogen or flourescent. Opinions?

    I do have blown-in insulation in the ceiling, I assume there are recessed light fixtures rated for install in insulation. If this goes good, I am going to replace my overhead lights in the garage next. I would of course liek to save on electric cost, which style is supposed to be more cost efficient, halogen or flourescent?
  6. Billy_Bob

    Billy_Bob In the Trades

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    Fluorescent uses much less electricity. A new type of bulb is LED which should use even less electricity. I have not seen these for sale in my area yet.

    Also LED and fluorescent bulbs operate very cool as compared with an incandescent or halogen. Traditional ceiling light fixtures and even wall mounted fixtures can get so hot in the ceiling/wall, they will crack the insulation on the wiring! The insulation just falls off the wiring!

    These days new wiring is required which will withstand these high temperatures.

    If it was me and I was installing any type of ceiling light fixture which could hold a traditional bulb or halogen, I would be sure there was no insulation over the fixture or surrounding the fixture in the attic (well ventilated). Somewhere for all that heat to go.

    Also might want to check out the prices of replacement halogen bulbs. Not cheap...
  7. hj

    hj Moderator & Master Plumber Staff Member

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    halogen

    Halogen bulbs are used in cooktops for the burners so that should give you some idea as to how hot they run.
  8. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

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    Correct. Those recessed fixtures are rated as "IC" (Insulation Contact). If you're installing them in an unconditioned space (probably so, if there's insulation there), then you should also get fixtures rated as "AT" (Airtight).

    Every IC/AT fixture I've seen, from cheapos to Halos, are far from airtight. I have no clue what AT really means, but I fill all the gaps and holes with fireproof caulk, mainly to deter critter infestation. No fires (or critters) yet.
  9. PEW

    PEW DIY Senior Member

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    If you are looking for good AT units look at Lightolier, but hold on to your wallet.
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    There are some guidelines on the lumens per square foot required for various levels of tasks (reading and crafts takes more than say mood lighting). Compare what is required for the task at hand, look at the spread of the lights and fixtures you want, determine the proper spacing, then see if you have enough power available. If the room is multitasking, either use multiple zones or dimmers to adjust the lighting level. You have to decide if you can accept 'holes' in the light pattern, or leave all the lights on, and adjust their level to best accomplish your desires and needs.
  11. dabiz7

    dabiz7 New Member

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    Thanks for all the input !!! I am currently looking at whats avaialble at the box stores....First will be the hallway, three or four lights, these will replace the three light center fixture....then the garage, currently just two exposed bulbs for a good sized two-car garage, I would like to run maybe 4 floods, think I will need 6? might have to add another branch for the additional lights?...

    Any more details about 'fire-proof caulk'? where do you buy that? Is this because the units that are marked for insulation really aren't? not clear on this point

    Thanks!
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Not all of the AT rated IC contact boxes are really all that air-tight...to handle the heat, you need a special caulk if you decide to 'improve' their performance.

    The key to getting even lighting is knowing the ceiling to floor distance, and the angle of coverage of the fixture and bulb used. Recessed fixtures are more prone to islands of light than bulbs and fixtures that are surface or hung. Just depends on what you want and the effect you are trying to achieve.
  13. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

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    It's sold at the big box stores. Used to seal holes where cables, etc., pass through firewalls, into attics, etc. I use it in the cracks & gaps in the cans mostly to keep the critters in the attic from getting into the house, but it does prevent air movement as well, and makes the so-called airtight units airtight.
  14. mc_1_2_3

    mc_1_2_3 New Member

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    Location:
    Western Pennsylvania
    Garage lights

    I would recommend 4 or 8 foot flourescent fixtures in the garage. There never seems to be enough light when you want to work on something. I am building a new house with a 28x32 garage right now. I plan on installing five two tube 8' fixtures in the garage. One length-wise above each car, then another one about 5 feet from the end of those. The last one will be above the work bench at the rear of the garage. They are all High Output fixtures that will light at 20 below zero. FYI, if you have a Big Lots store near by, I found these fixtures for $20 each. They are at least $55 at Lowes.
  15. dabiz7

    dabiz7 New Member

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    I was thinking about 4' or 8' flourescent fixtures in the garage. Do these use less total amps than a incandescent lamp? I just thought some recessed lights would look a little stylish. Would put a flourescent over the workbench.
  16. mc_1_2_3

    mc_1_2_3 New Member

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    Location:
    Western Pennsylvania
    They are 95 to 100 watts per bulb or .79 to .83 amps per bulb, assuming 120 volts. Therefore, with 5 fixtures, I will have 1000 watts of light, nice and bright. I will have seperate switches for them, 1 for the bench, one for lights above cars, one for lights in front of cars. It is worth it to be able to see. I do alot of work in my garage and the lighting helps. I may even seperate them further to save a little electricity, just have the one closest to the door on a switch. The lighting for my garage will need its own circuit. I will likely go with a 20 amp breaker and put a couple outdoor lights on the same circuit.
    Last edited: Jun 11, 2008
  17. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

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    I'm about to replace all the incandescents in my garage with fluorescents. Planning on wiring them into the garage door operator system so they can be turned on and off remotely, but that plan isn't fully baked yet.
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