FAQS: DAYLIGHT



Why we can save money with natural light?

Because we spend 90% of our life inside a building May be that’s why buildings consumethe 40% of the totalenergetic consumptionin Europe. And artificial lighting represent more than 30% of the energeticconsumption of a building.


Why we can save money with daylight?

According to European Union statistics , Europeans spend 90% of their life inside buildings. May be that’s why energy consumption in buildings is 40% of the total energy consumed by Europeans. Transport is the 32% and industry the remaining 28%. But what is most important, 19% of the total energy consumed in the world is due to lighting. We can see that buildings in general and lighting in particular, represent one of the sectors with more energy consumption in the European Union , That’s why it is a great opportunity to save energy, save money and reduce our CO2 emissions.


What about CTE Spanish section normative?

Spanish CTE establishes that artificial lighting near sunlight sources should have a regulation system in order to take profit from sunlight. But it doesn’t establish any minimal values of the daylight a building should have. Why? It’s clear that if we want to obtain important energetic savings due to systems that regulate artificial light, we should design buildings that take maximum profit from natural light.


What about the European Union statistics?

According to European Union statistics , Europeans spend 90% of their life inside buildings. May be that’s why energy consumption in buildings is 40% of the total energy consumed by Europeans. Transport is the 32% and industry the remaining 28%. But what is most important, 19% of the total energy consumed in the world is due to lighting. We can see that buildings in general and lighting in particular, represent one of the sectors with more energy consumption in the European Union , That’s why it is a great opportunity to save energy, save money and reduce our CO2 emissions.


Which Factors have an influence lighting consumption in a building?

The energetic consumption in lighting inside a service building depends on many factors, the main ones are the following:

  • Lighted surface: S (m2)
  • Average iluminance level : E (lux)
  • Annual service hours: h (hours/year)
  • Energetic Efficiency Value of the Installation: EEVI (W/m2.lux)
  • Electric rate (Euros/Kw.h)
  • Architectonic elements and decoration
  • Control and regulation systems
  • Ability to profit natural lights.