It is not just about the recording lighting level (known as LUX)
Lighting efficacy – Energy audits for buildings, typically include a lighting audit. But just recording the lighting level (known as the lux level) in the various rooms is not enough. We need to assess the effectiveness of the installation.
During a recent energy audit several lighting fittings (as shown in the photograph) were discovered. Perhaps discovered is the wrong word, the high intensity fittings were plainly obvious.
Pairs of uplighting fittings were installed close to each other, and very close to the ceiling.
These fittings didn’t add any value to the illumination of the space, as you can clearly see these intended uplighters only created an intense, localised pool of light (and heat).
Based on operating 3,600 hours per year, each fitting wastes HK$ 660 per year in electricity. Just measuring the lighting level is not sufficient for an energy audit, in this case immediate removal was recommended saving electricity.
Also remember that in air conditioned rooms removing lighting fittings not only lowers the electricity consumption for lighting, it also lowers the heat gain which in turn reduces the load on the air conditioning system. As a rule of thumb, eliminting 1 Kw of lighting lowers the total electricity consumption by 1.3 kw.