LED Lighting Technical Terms

Kelvin color temperature: the color of light is measured in units of Kelvin (color temperature). The lower the Kelvin temperature is, the warmer (or yellower) the light is. The higher the Kelvin temperature is, the cooler (or bluer) the light is. The traditional incandescent bulb is 3,000K or lower, which is what we recommend going with when replacing indoor lamps or fixtures (with the exception of fluorescent linear or metal halide/pressure sodium bulb) and is the most popular color temperature.

CRI (color rendering index): in non-technical terms the CRI indicates the quality of light when illuminating objects. The higher the CRI is, the better the quality of light it is and ranges from 0-100. The object that is being illuminated will look more colorful and radiant with a high CRI light in comparison to a lower CRI light. For example, if you are reading a book you will be able to see it better with a high CRI light and have less strain on your eyes. Generally as the color temperature (K) goes up, the CRI goes down in an identical light bulb, but the brightness (lumens) increases.

Power factor: in non-technical terms the power factor defines how “efficient” something uses the power in relation to how much power it draws and ranges from -1 to 1. The closer the power factor is to “1”, the more efficiently the load uses the power it draws.

For most consumers, the power factor does not affect their electric bill since the utility company does not measure it. Some industrial businesses that use a lot of heavy machinery may however, be penalized by their utility company if their overall power factor is below a threshold.

Lumens: a lumen is a measurement of how much light a bulb produces. Although it is a good idea to compare LED lumen output to the traditional bulb being replaced; however, it is important to realize that many times LED lumens vs other types of bulbs cannot always be compared 1:1 because of the directional nature of LED lighting. For example, in many applications part of the light from a traditional light bulb gets lost in a reflector, but LED bulbs can be designed to project light only in the direction where it is useful.

Types of bases: the most common bases are:

E26 (medium): this type of base is most widely used in standard household screw-in bulbs and is 26mm in diameter. (Click here to view Green Ignite bulbs with E26 base.)

E39 (mogul): this type of base is a screw in base that is larger in diameter (39mm) than the smaller E26 base. (Click here to view Green Ignite bulbs with E39 base.)

E12 (miniature): this type of screw in base is much smaller in diameter (12mm) than the E26 base and is generally found in candelabra bulbs. (Click here to view Green Ignite bulbs with E12 base.)

GU10: this is a relatively popular base with MR16 and other bulbs. It is a 2-pin bayonet-style twist lock base with pins 10mm apart. Bulbs with GU10 base are designed to work off of AC voltage. (Click here to view Green Ignite bulbs with GU10 base.)

GU5.3: this type of base is used mostly with 12V MR16 bulbs, but sometimes used with in-line AC voltage MR16 bulbs as well (more rare than 12V). It is a two-pin base with pins 5.33mm apart from each other. (Click here to view Green Ignite bulbs with GU5.3 base.)

G24 or GX23: this type of base was originally used with compact fluorescent (CFL) bulbs. Now LED replacement bulbs are available with the same base. This type of base comes in 2-pin or 4-pin variation. The difference between G24 and GX23 is very slight (the pins are exactly the same but the plastic part is slightly different) but it is important to choose the right base during retrofits. (Click here to view Green Ignite bulbs with G24/GX23 base.)

G4: this 2-pin base is typically found in 12V miniature bulbs with the pins being 4mm apart from each other. (Click here to view Green Ignite bulbs with G4 base.)

G9: this 2-pin base is typically found in AC line-voltage miniature bulbs with the pins being 9mm apart from each other. (Click here to view Green Ignite bulbs with G49 base.)

G13: this 2-pin base is typically found in fluorescent linear or LED linear replacement bulbs. (Click here to view Green Ignite bulbs with G13 base.)

Fa8 base: this single pin base is found in 8ft fluorescent linear or LED linear replacement bulbs. (Click here to view Green Ignite bulbs with Fa8 base.)

Bayonet base: this is a push-twist-and lock type of base and is generally used in miniature bulbs. This type of base is found with different diameters (Click here to view Green Ignite bulbs with bayonet base.)

LED Bulb Types:

A-type: this type of bulb is round and is used in all general applications. A-type bulbs come in different lengths and diameters. (Click here to view Green Ignite A-type bulbs.)

Candelabra: this type of bulb is generally used in chandeliers. (Click here to view Green Ignite candelabra type bulbs.)

PL: this type of bulb is generally used in recessed lighting and come with G24 or GX23, 2 or 4 pin bases. (Click here to view Green Ignite PL bulbs.)

T12, T8 or T5: this is a linear tube bulb that is generally used to light offices or warehouses. The general difference between the 3 types of bulbs is their size in diameter Click here to view Green Ignite linear tube lights.)

PAR/BR/MR: this type of bulb is generally used in recessed light fixtures and come in different lengths and diameters. (Click here to view Green Ignite PAR/BR/MR bulbs.)

Metal Halide/Low Pressure Sodium/High Pressure Sodium: these types of bulbs are generally used in commercial warehouse settings or in street lights/parking lights. E39 mogul or E26 medium bases are generally used with these bulbs (Click here to view Green Ignite Metal Halide replacement bulbs.)