Anonymous
Anonymous asked in 科學及數學其他 - 科學 · 1 decade ago

慳電膽 -- for eye health

慳電膽 --- how many watt under 100 square feet dining room is suitable for eye health??? some too more bulb be too bright, any test result for reference??? I need professional idea to buy the light and bulb. thanks a lot.

2 Answers

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  • 天同
    Lv 7
    1 decade ago
    Favorite Answer

    Let us treat this problem in a scientific way.

    The illuminance at a residence should be in the range from 100~300 lux (lumen/m^2), as given in the Code of Interior Lighting produced by the Chartered Institute od Building Services Engineers. Please refer to the follwoing web-page:

    http://www.arca53.dsl.pipex.com/index_files/lightl...

    Taking an average illuminance of 200 lux at the dining room, and assume that your dining room has a height of about 3 m, the luminous flux at a compact flouresent lamp (CFL) installed at the ceiling is

    = 200 x (4.pi.3^2 ) lumens = 22600 lumens

    where pi = 3.14159...]

    To produce 22600 lumens, a CFL of 340 watts is needed. See the follwoing web-page, at the table under "energy efficiency"

    http://en.wikipedia.org/wiki/Compact_fluorescent_l...

    However, the above simple calculation assumes no reflection of light from the walls, ceiling and floor; and also the light comes from a single light source.

    In the actual practice, you could reduce the CFL wattage by nearly half if shiny wall finishes have been used. Also, by spreading the light source into about 5 evenly spaced CFLs over the 100 square feet room, then each CFL should be of power 34 watts,

    Notice that the above calculation is only a crude estimation. As the average illuminance at the room depends to a large extent, the decoration inside the room and the wall finishes, which reflect light to different extent. A room with dark coloured wall definitely needs more CFLs than walls with bright colours.

  • Anonymous
    1 decade ago

    慳電膽都有講幾多火架.

    咁你話一百平方尺,咁係正方型定係長方型呢?

    咁你係用白光嘅慳電膽係唔係?咁建議你用6隻白光燈就夠用,我諗你樓底都係一般啦,咁我新買嘅水晶燈係本來烏絲黃燈膽,但係白光燈就唔同計法,因為白燈火數係少過烏絲黃燈嘅,咁白光燈係廿火一個,六個就係百二火,而黃燈就會唔只百二火,但係照明一樣.

    你不妨去行吓旺角砵蘭街賣燈飾嘅,揀啱問人一百平方尺要用幾多火啦.

    Source(s): 自己
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