Warm light versus cool light
Warm and cool refer to the colour temperature of light, which is different from brightness (lumens) and energy usage (watts).
Darren says it’s easy to remember the difference between warm and cool through colour. “Warm light is yellow and cool light is blue. So, if you think of the light from candles, that’s yellow and soft. If you think of a really sunny day with an open blue sky, that light is blue and a bit sharper.”
Colour temperature explained
Colour temperature is described more accurately through the measurement of kelvins, which has the symbol K.
A decorative globe with a vintage-look has a warm colour temperature of around 2400K and gives off a soft yellow light. Whereas a daylight white LED light has a cool colour temperature of 5700K.
“With colour temperature, the higher the temperature, the cooler the light. That is the opposite to what we’re used to,” Darren explains.
Colour temperature has no relation to the heat given off by the light globe. In fact, there is very little heat produced by most LED light globes.
Where to use warm light
Warm light is best in an environment where we’d like to be comfortable and relaxed. Darren recommends that, “warm lights are better for residential applications such as the lounge room, in the kitchen, at the dining table and in bedrooms.”
Cool light colour temperature is closer to daylight and can have an impact on our sleep patterns. That’s why many electronic devices, such as smartphones have a warm light setting for use in the evening.
For that reason, many people prefer warm light in bedrooms and living rooms, particularly when it’s close to bedtime.
Where to use cool light
Cool light is used in shops and workplaces, where you want to be able to see clearly and particularly if you are concentrating. Darren says the same principle applies in our homes. “Cool lights are better for security, in the garage, bathroom, kitchen and in task lamps. Anywhere that you’re working, rather than relaxing.”
In multi-function rooms it’s possible to have both warm and cool lights, depending on how the room is being used. For example, in a bedroom with a warm ceiling light, you can also have a cool light lamp on a desk for reading and studying.
Choosing the right light
All energy efficient LED lights are available in a range of colour temperatures from warm to cool. In fact, many LED lights give you the option to adjust the colour temperature in the same way you adjust brightness.