The jargon in the lighting world can often get mixed up. Color rending index (CRI) and color temperature are one of the most to be confused with each other. This post is going to clarify what the different between CRI and Color Temperature is so we can end this confusion.

Here is a short explanation why the CRI is more important to focus on before deciding for a color temperature. The color rendering index is the most important feature in certain applications as it determines the appearance of objects, faces and spaces. If this aspect is not relevant, the CRI can be as low as 60 or even 40.

The color rendering index (CRI) is a numeric evaluation of the light color accuracy with the reference of daylight (numbered 100). Sunlight and its broad spectrum will enable a person with normal vision to see 68 different colors in a color chart, but if the chart is illuminated by a light source of one wavelength only, each color from the color chart will appear as a different brightness of that one color. Some activities, such as walking or operating a vehicle, do not require the accurate perception of surface colors while others such as product selections in shops benefit from better color rendering features. Look at the application of the lighting installation. If the visual tasks are easy to perform the CRI doesn’t need to be high. In areas like offices, handcraft manufacturing and surgery, the requirements for visibility, contrast, visual guidance as well as face recognition need to be provided by a lighting system with a good CRI of >80 or even >90.

How much is the light color affecting the space? The term color temperature describes the temperature of objects by which they emit light, modeled through the “blackbody radiator”. When increasing the temperature of a “blackbody”, it starts to emit visible light in a continuous spectrum. The filament of a 60W incandescent lamp heats up to about 3000°F, as a result the lamp emits light with a color temperature of 3000K. Many of our artificial light sources do not create light by heating up a material until it glows like an incandescent lamps. Instead of creating a continuous spectrum, they generate an assortment of color emission lines. A blackbody color temperature cannot be directly given to this non-blackbody type of emission, generated by high intensity discharge and fluorescent lamps for example. For those light sources, a correlated color temperature (CCT) is indicated, based on the blackbody color temperature. A cool white fluorescent lamp has a CCT of about 5000K. The lamps light spectrum is different from a blackbody one but has the same temperature.

The light color influences the atmosphere in a space. The more cozy the ambiance the warmer the light color (lower color temperature) should be and the more dynamic the scene the cooler the light source (higher color temperature). The CRI is the most important factor to watch when choosing light sources. How good is the light source representing faces, colors and contrasts? The easier the visual task and perception the lower the CRI can be. The color temperature needs to be watched second, it is supporting the space’s atmosphere.

Conclusion

There you have it; an explanation of both the Color Rending Index and Color Temperature.

Have anymore questions or thoughts? Comment them down below!

Two costs are associated with any electrical appliance: the buying price, and the running cost in terms of energy and maintenance. Of the running costs, energy is one of the major items. Typically, the equipment can last several years before requiring a major repair.

Consumers should therefore not just look at the price tag on the item.  Rather, pay attention to its energy rating and available energy saving modes.

Energy star certified refrigerators and freezers are at least 9 and 10 percent more efficient respectively. Other considerations that help in saving energy include selecting the adequate capacity. In addition, the refrigerator or freezer should be kept in a cool place away from heat sources such as direct sunlight or ovens.

More energy savings can be realized by using the proper settings. In addition, ensure the door is closed all the time and that seals are in place. Place the refrigerator or freezer in a spot that allows free air circulation around the fridge; especially at the back where there are cooling pipes.

Manual defrost freezer models use less energy and are therefore more efficient than the automatic defrost models. Another important factor is the design of the freezer. An upright freezer with shelves is easier to organize. However, the chest freezer may be more energy efficient since there is less cold air escaping from the door which opens from the top.

These are usually 40 percent more efficient than the standard purifiers. Other factors to consider include the room size and placement. Select a model adequate for the room; otherwise, an oversized air purifier or cleaner will end up consuming more power unnecessarily.

Energy star certified dishwashers use at least 12 percent less energy and 15 percent less water than the conventional models. However, this may vary depending on the model and other factors.

These dishwashers utilize more efficient technologies that reduce both the energy consumption and water usage. For example, the design uses soil sensors that check the amount of dirt on the dishes.  An optimized cleaning cycle reduces the minimum amount of energy and water. In addition, there are more efficient water jets and a dish rack design that ensures efficient use of water and energy.

Energy Star dehumidifiers

Certified dehumidifiers use 15 percent less energy. They utilize more efficient compressors, refrigeration coils, and fans.

Washing machines

Energy star certified washing machines are usually 25 percent more energy efficient than their equivalent standard models. In addition, they use 40 percent less water. This results in the consumer saving water, as well as energy for both the washing machine and the water pump.

Clothes dryers

Certified dryers use at least 20 percent less energy than the standard models. The equipment utilizes more efficient technologies such as heat pumps. Moisture sensors automatically stop the drying cycle once the clothes are dry. This sensor-based drying machine is more efficient compared to thermostat or timed drying, which continues to consume energy even after clothes are dry.

Televisions qualify for energy star certification when they become at least 20 percent more efficient. Some models can reach up to 40% better efficiency than traditional models, while the set-top boxes can achieve up to 45 %. However, the amount of power used depends on the size of the TV screen, display technology, and resolution.

The home theater systems that are energy star certified are 60 percent more efficient. Certified battery chargers for small household appliances such as power tools, electric shavers, and cordless gadgets use 30 percent less energy.