Whether you're upgrading outdated incandescent systems or implementing new lighting solutions in residential commercial buildings, understanding the different light bulb sizes is crucial. Light bulbs have different distinctive characteristics that help us set them apart. The bulb sizes are identified by letters and numbers to indicate their features. 

In commercial applications, several common light bulb sizes are widely used to meet various lighting needs.  A type and T type bulb are often found in offices and retail spaces, offering a balance of brightness and efficiency. In high-ceiling or industrial settings, BR and PAR light bulb sizes are popular to support specific lighting needs.

In this article, we'll explain how to tell different types of light bulbs apart and the differences between their sizes, so keep reading to learn more about this topic.

Understand Light Bulb Names

Each light bulb is named using a letter and a number. The letter refers to the shape of the bulb or a special feature like the reflector type in the bulb.

The number indicates the diameter of the bulb, which is measured in millimeters or eighths of an inch. The combination of a letter and a number indicates the size of the light bulb, so you can pick a bulb of an adequate shape and size.

BR Series

"BR" is the abbreviation of "Bulged Reflector". Its feature is the reflective surface of the lamp body which is designed in a convex shape. Compared with ordinary R-type bulbs, BR type has a larger light diffusion angle, a wider illumination range and softer light. BR type bulbs are often used in places such as household downlights and ceiling lights where uniform lighting is required.

PAR Series

PAR series bulbs are named after the Parabolic Aluminized Reflector. This is different from the U-shaped reflector that is used in incandescent bulbs.

The parabolic aluminized reflector is used to maximize brightness and direct the light to create a narrow or wide beam. The bulb has a shorter body and is usually installed by being flushed to the ceiling or other fixtures to reduce glare.

PAR bulbs are usually used for emergency outdoor lighting or spot lighting because the light from these bulbs doesn't fade as much as other types of bulbs. They also operate using low-voltage wiring, so they can be used in landscape lighting.

G Series

G series bulbs are commonly used in home applications. They're round-shaped and come in various sizes to suit various purposes. "G" stands for "Pin". According to the differences in the number and spacing of the pins, it can be further classified into multiple types.

You can use G type bulbs as kitchen lights, foyer lights, or in chandeliers and ornamental fixtures. They can also be used as vanity lights or have a gold tint for a decorative effect. Although they come in different sizes, the most common bulbs are the bigger ones.

T series or tubular bulbs can be used in wall sconces, garage lights, in pendants, and as basement lighting. T-shaped bulbs were mostly fluorescent tubes in the early days, but now they are mainly LED bulbs. These lights come in various sizes, so you can pick the right one for your application.

It is suitable for places that require linear light sources, such as cabinet lighting, bathroom mirror front lights, office lamps or industrial lighting.

How to Choose Right Light Bulb Size for Your Lighting Need

Choosing the appropriate bulb size for commercial lighting requires comprehensive consideration. First of all, the physical size of the bulb must be compatible with that of the lamp. Different types of lamps, such as downlights, panel lights, chandeliers or track spotlights, have specific requirements for the length, diameter and shape of the bulbs. 

For instance, recessed downlights typically require smaller-sized LED bulbs, while large chandeliers may be compatible with standard A19 or A21 bulbs. If the bulb is too large, it may not be installed or affect the heat dissipation of the lamp. If it is too small, it may lead to uneven distribution of light.

Also, the specification of the bulb base must match the interface of the lamp. Common types of bulb base in business environments include E26 and GU10. Choosing the wrong model can result in installation failure. In addition, some special lamps may require bulbs of specific sizes.

Finally, the size of the bulb also affects the luminous efficiency and heat dissipation. High-power LED bulbs are usually larger in size to enhance their heat dissipation capacity. Compact bulbs are suitable for space-constrained situations, but they may sacrifice some brightness or lifespan. Therefore, while meeting the lighting requirements, it is necessary to ensure that the selected size can fit the lamps and optimize their performance.

Conclus​ion

Light bulbs come in all shapes and sizes, and their shapes and sizes are indicated by a letter and a number. The letter indicates the shape of the bulb and affects how it can be used. Light bulb sizes don’t have to be confusing. Once you crack the code, deciding lighting solutions becomes way easier and more satisfying.

The number refers to the diameter of the bulb in eighths of an inch. Some types of light bulbs are interchangeable, but in most cases, every specific light bulb is suitable for a certain purpose. In a market moving towards energy efficiency and sustainability, getting bulb sizin​g right is a key operational advantage.