by ericmark »
Mon Nov 08, 2010 7:01 pm
With a correctly designed system a living room needs around 100W of light but use small lamps which produce more heat than light the same room will need 500W of lighting to get same results.
Most of the problem is lamps that are physically too small. A 60W florescent tube will light a room far better than a 60W spot lamp. A spot lamp is as the name suggests designed to light just one small area like a picture on the wall.
Even the 60W florescent has many flavours with some tubes having coatings to send more light down and less up to ceiling and by using HF running gear they use less power than the inductance controlled models.
Room height also has a profound effect when we changed a workshop with a low ceiling lights from florescent to 70W Metal Halide it was a failure but same job with 15 foot ceiling was great.
Also room colour will effect the result. As you can see rather involved so no simple answer.