What is color temperature?
The color temperature of a light bulb is the temperature of an ideal black-body radiator that radiates light of comparable hue to that of the light source. Incandescent lamps are assigned a color temperature based on the type and thickness of the glass envelope. The higher the color temperature, the bluer white would be.
It is measured in Kelvins and the temperature of a candle is about 1,900K.
What makes LED lights more energy efficient?
LED lights are more energy-efficient because they produce less heat than incandescent or fluorescent lights while still producing enough light for everyday life functions. This is done by using semiconductors instead of filaments or gas in standard bulbs. Because LEDs convert most energy into visible wavelengths rather than invisible infrared radiation, they are also cooler which means they are safer to use around people and pets.
How does color temperature affect your eyes?
LED lights typically produce a different wavelength of light, which makes it harder for our eyes to see the difference between red and blue objects. This is why the white LED bulb appears bluer than other bulbs because it produces more blue wavelengths.
As a result, diabetics must adjust their insulin doses if they are frequently exposed to LED light because their bodies might not be able to tell how much sugar isn't being absorbed as a result of not producing enough or too much insulin according to the amount of blue light that enters the eyes.
Why do you need to change the LED light temperature?
Reasons for changing it include:
- if your eyes feel tired or you are experiencing eye strain, it might be due to the LED light frequency. The best way to fix this problem is by changing the LED color temperature so that the blue wavelengths are reduced.
- diabetic people need to reduce their insulin intake when exposed to more blue light because their bodies cannot tell how much sugar isn't being absorbed as a result of not producing enough or too much insulin according to the amount of blue light that enters their eyes.
- If you're using LEDs for growing plants specifically, then warmer colors (2700K) would help stimulate vegetative/leafy growth and cooler hues (5000K) would promote flowering. Just make sure you don't go too far out of the spectrum or your plants will die.
How to change LED lights temperature?
To make LED's light warmer, an orange or yellow cover must be used on the bulb. For example, normal LEDs emit around 6000-6500k, but if you buy bulbs that are between 2700-3000k then it will emit a "warm" light which is more like incandescent lighting (which emits brighter too).
Another way to make an LED lamp produce a warmer glow is by using two LEDs with different color temperatures in parallel circuits. The LEDs should be mounted closely and wired in parallel wire connections to provide better heat distribution and balance over the whole surface of the diode. The finished assembly should be encapsulated to prevent the light from escaping. Doing this will make LED lights emit a warm glow (about 2200-2700k).
If you can't afford to change your LED lamp then just use an "amber" or orange cover in front of the bulb which will reduce the bluish/greenish color and produce a warmer light.
Alternative variants
However, you can use some variations. They may happen to be more affordable or convenient, depending on your purposes.
- Color filter for warmer light
Color filters were invented to change the color temperature of the light bulb to produce "warm" or "cooler" white lights. For example, if your lamp emits 6000k and you use a yellow filter (lowering it to 3000-3500k), then you're making the lamp emit a "warmer" glow.
If using this method, make sure that the sum of all bulbs' color temperatures does not exceed 5000k, or else the lamp's light won't be able to adjust properly and might overheat and even explode.
There are different types of filters for LED lights, but we will stop at CTO (color temperature orange) filters for this example. What does it mean? This filter will change the color temperature of the light produced by your lamp to 3600k (an orange-ish glow). This means that this filter absorbs some blue and green wavelengths while passing more of the yellow/red ones.
Using color filters was made quite popular especially by photographers, for portrait or landscape pictures - warmer colors look much better on pictures than colder ones. So if you need warm light for taking pictures, using a CTO filter will be best. It can also be used if you want to relax in "warm" light instead of looking at bluish LEDs. A good example is that some people prefer red lights in their bedrooms because it's easier to fall asleep while watching TV beneath them.
- Painting LED bulb for warmer light
Painting LED lights with orange paint is also a simple and efficient way to change their color temperature. However, this method will reduce the light's intensity and you should take that into consideration if brightness is important for you. Do not use black or dark-colored paint because it will absorb too much light and might even melt your lamp!
A good idea would be to use bright orange-pink paints such as those used in the past by Tungsten lamps. Another example of how painting works: if you want warm golden/yellowish lights then use yellow or gold-colored paint - just make sure that these colors won't suck out too much energy from your LED bulb. Keep in mind that some types of paints are more effective than others.
Note, that you should take only a certain type of paint for this method, not all types will create the desired effect. For example, if you use metallic paints then they might heat up and produce an unpleasant burning smell.
- LED lamp with two color temperatures
Another "hack" that can help you reduce undesired blue and green colors from LEDs is to purchase a lamp that already has different light colors. These lamps are often called "two-color", "warm/cool", or "daylight/warm white" lamps (the opposite would be also true: buying a lamp with only one type of LED in it).
The idea here is that such lamps supply warmer light when using both LEDs at once (usually when connected in parallel), but when using only one LED, the other part doesn't work and thus produces bluer light.
But if you only need the warmer type of light, then purchase a lamp that has two or more types of LEDs in it - just make sure that both have a different color temperature! Remember to think about what kind of lighting will suit your needs best before purchasing a lamp whose LED colors are not customizable.
- LED lamp with adjustable light color
Some lamps allow adjusting their light color by turning some knob on the outside (or inside), which allows choosing between several color temperatures. However, this option can be hard to find because most people prefer buying "ready" lights instead of making them themselves (buyers generally expect all necessary equipment to already be there). If you're lucky enough, however, and can find a lamp that allows you to adjust its color temperature then it will be the best option for you if you need warm light.
- LED lamp with local dimming
You can also adjust LEDs' "native" color temperature by turning their brightness up and down. Some lamps offer this feature, called "local dimming", so search for it before buying your next lamp.
This will give you much more options because adjusting brightness might also influence the intensity of the bulb! It's great because there are many situations when we don't need maximum brightness from a lamp but just a little bit of a softer glow, right?
Note: all types of filters mentioned earlier still work while using local dimming! However, keep in mind that changing intensity can fool our eyes into thinking that the LED color is different.
- Combining different ways of heat dissipation to achieve better balance and efficiency
LED lights that are evenly heated will provide more even light distribution while keeping the LED bulb/lamps from over-heating. If you combine all three methods mentioned above properly and in a smart way, then your LED light would be able to emit warmer light while providing greater intensity AND it also won't be as likely to burn out too quickly or explode (which happens if you don't use any sort of protective cover).
However, there is no need for such complicated setups - just pick one method and stick with it. If you want warm lighting but can't afford to change the color temperature of your lamp, using a CTO filter is the best solution. You can attach it to your LED light and never think about it again.
If you're serious about photography, then use color filters to make your lamps emit warmer light. If you prefer a warm glow of 3000-3500k and don't mind spending a few bucks on that, go for the color filter option - or even better: buy two different types of covers (one CTO and one orange) and combine both during winter for some "warm winter" lighting!
Experiment with them if you like; get ideas about their efficiency (or inefficiency). It's always better to know what works best for you before buying new lamps/bulbs/covers or changing any of the parameters in your setup.
However, if after experiencing LED light in your room you like it very much and don't want to change anything, then just go for it - do nothing. It's great that you made up your mind regarding this option!
How can you make fluorescent and halogen light warmer?
Fluorescent and halogen lights are usually not adjustable (unless they're dimmable) but there's another way to make them warmer - use colored filters or covers, just like with LED lamps! For the best results with fluorescent lamps - choose a color temperature of 3500k.
These lamps are not adjustable because their emissive materials are already inside them, along with gases that emit light. Changing their temperature would change how much energy they're outputting to produce light - changing intensity can also result in different colors of lighting (and you don't want this).
The main reason fluorescent lamps are not adjustable is that if you change something about them, it might make their lifetime shorter or even stop them from working at all. Keep it safe and don't touch anything related to their mechanism!
However, because fluorescent tubes are very long, you can cut one tube and insert a new lamp in the middle of the previous one: this way you'll get both warmer and brighter light in your room - depending on which parts of the original tube were cut.
Additionally, for more efficient usage of fluorescent lamps, you could attach additional extensions to them - this would also change their color temperature because these "add-ons" are usually coated with orange/red colors.
Since halogen lights have a glass enclosure around them, it's better not to break or modify anything about their shell - instead, just cover it with something that will reduce the output of blue light! Yes, both halogens and fluorescents emit lots of blue/cooler light too!
Because of this problem, using filters is the best choice here. It'll be easier than changing your whole setup but still provide similar results if done correctly. You can find colored plastic sheets at hardware stores or online shops specialized in lighting. Most of them should be able to help you with your project - just mention what kind of lighting equipment you have and what it's color temperature is, so they can help you choose the best solution.
Another option would be to try your hand at painting or coloring the lamp cover in some way - this will definitely add a nice effect to any room! It gets more complicated when we're talking about other types of lamps but these two should work just fine if done correctly.
Final words
It's not very difficult to make your lighting warmer or colder. All it takes is making sure that the color temperature you're aiming for matches what kind of lamp/bulbs you're using! If you're still unsure about which light is right for your room after reading this article - just go with 3500k or 3000k and be happy that your room looks great!