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Light Quality, Kelvins & Lux Levels

2nd April 2020 | by Energy Oasis

The diagram below explains the Kelvin scale. It is important to understand that electric light is relatively new to us. It has been common place for the last 80 years, before that we had candles or gas/ paraffin lights. Then we invented the bulb and most places received mains electricity; to make light we heated a wire inside a gas. Depending on the type of gas we either got an orange light or a yellow light. Unfortunately 80% to 90% of the electricity consumed was wasted as heat, the remainder allowed for light. We used reflectors to direct the light; this has been the status quo for some time, until LED lighting became commercially viable approximately four years ago.

LED, (Light Emitting Diode) allows the manufacture of a much more efficient light, however initially the light produced was very “blue/ cold” this was between 7000 to 10000 kelvins. It’s a sterile light.

In the last two years we have been able to make a light which more closely resembles or even matches natural light. This is between 4900 and 6500 Kelvins. All lighting installations in offices, commercial, manufacturing and retail environments should be in this range. It is better for our health and wellbeing. It improves our efficiency and reduces stress in the work place.

Lux Levels

The Chartered Institution of Building Services and Engineers (CIBSE) produce a guide line of what lighting level is required in different environments. This is also endorsed by the Lighting Industry Association. For example, Offices and small retail premises require 300 to 500 Lux; show rooms 500 to 750 Lux; while warehouses and distribution 100 to 300 Lux.

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