How Much Lighting
Determining the correct light levels for a home environment is a very complicated subject and depends to a degree on the individual’s perception and requirements. The formula below, however, can be used as a rule of thumb.
Measure the room size in square metres and multiply this by 25 (for incandescent lamps) 15 (for halogen lamps) or 19 (if using compact fluorescent lamps). This will give you the total watts required to light the room.
Example 1
A room 5m x 5m has an area of 25 sq metres. If we are to use conventional incandescent lamps we multiply this by 25 giving a total wattage of 625 watts. This can be made up as required, for example as follows:
- 2 x 75w table-lamps = 150w
- 2 x 3 light ceiling lights each with 40W bulbs = 240w
- 2 x double wall lights each with 40W bulbs =160w
- 2 x single wall lights each with 40W bulbs = 80w TOTAL = 630w
Example 2
A kitchen 3m x 6m = 18 square metres. If we intend to use low voltage halogen dichroic lamps then we multiply this by 15 to arrive at 270 watts required in total. This can be made up as follows:
- 1 x 3 light halogen bar fitting with adjustable heads each with 50W lamps = 150w
- 6 x down-lighters mounted in the ceiling each with 20W dichroic lamps = 120w TOTAL = 270w
Please note that this formula is a guide only and some people prefer more light, others less.
A useful measure is to over-estimate by 10-15% and install a dimmer to give you more control. If in doubt seek professional advice.
© Pagazzi 2007