4ft T8 Light Bulbs: Your Complete Tube Guide (2024)

  1. Home
  2. Blog Home

Posted by Dara Greaney on 11/9/2023 to

What is a T8 Bulb?

LED tubes are a modern and efficient alternative to fluorescent bulbs for recessed lighting. LED technology has transformed the lighting sector, allowing you to replace your old fluorescent tubes with LED tubes without changing the entire housing. LED tubes have many advantages over fluorescent bulbs, such as:

  • Faster turn-on time
  • Higher energy efficiency
  • Better color rendering
  • No flickering
  • Longer lifespan - up to 100,000 hours

Among the various types of LED tubes, T8 tubes are the most popular. They are used in different buildings and industries. The "T" stands for "tubular", which describes the shape of the bulb. The "8" indicates the diameter of the bulb in eighths of an inch. A T8 bulb is an LED tube lamp with a one-inch diameter.

Conventional fluorescent bulbs use electricity and mercury-vapor gas to produce light. LED T8 bulbs use LED diodes and a phosphor coating to produce light. The phosphor coating converts the blue light from the LED diodes into white light. Conventional fluorescent bulbs do not have a phosphor coating, but a fluorescent coating that emits light when excited by ultraviolet rays from the mercury-vapor gas.

What are the Types of T8 Bulbs?

The T8 LED bulbs are broadly classified into the following four groups:

T8 LED Type A (direct-fit) – Type A T8 bulbs are widely known for their price as well as ease of installation. These lamps function better when new ballasts replace the old fluorescent light ballasts. The replacement of the ballasts helps avoid early burnout and additional costs that usually arise from replacements.

T8 LED Type B (ballast bypass) – Many people prefer LED Type B bulbs to Type A. Type B is characterized by a direct electrical connection to the socket since the ballast is bypassed, meaning it contains an internal power supply. With the "double-ended" LED Type B, you do not need to rewire any existing connections but only bypass the ballast.

T8 LED Type A/B (hybrid with integrated heat sensor) – This is newer than Type A and B. It features an integrated circuit that recognizes the presence of any unusual heat. The integrated circuitry will immediately direct the tube to turn off in the presence of excess heat. This safety feature is significant when the fire is of great concern or poses great danger.

T8 LED Type C – In order to light up, Type C requires a remote power supply hence removing the potential of electric shocks. The feature also allows for dimming options. And it is hugely because of the dimming option that T8 LED Type C lamps can be more costly than the others. However, it is worth an investment in a setting where dimming features are essential.

4ft T8 Light Bulbs: Your Complete Tube Guide (2)

Tips for Purchasing T8 Bulbs

T8 LED tube lights are gaining popularity as a modern and effective alternative to traditional fluorescent tubes. However, before you buy one, you need to take into account some factors to optimize its performance and suitability. Here are some things to consider before buying a T8 LED tube light:

  • Tube Type: There are four major types of T8 LED tube lights: plug-and-play, ballast-bypass, hybrid, and dimmable. Each type has its own advantages and disadvantages, and is suitable for different applications. You should compare the product, installation, and maintenance costs of each type and choose the one that meets your needs and budget
  • Warranty: If you like to install and maintain the tube lights yourself, you should look for the ones that offer a 5-year warranty. This way, you can save hundreds of dollars on professional services and enjoy peace of mind.
  • Color: The color of the tube light affects the mood and atmosphere of the space. If you need lighting for an office or a workspace that requires attention and focus, you should opt for daylight white, which has a color temperature of 5000K or higher. If you need lighting for a relaxing or cozy space, such as your living room or bedroom, you should go for warm white, which has a color temperature of 3000K or lower. Most LED tubes are used for spaces that require attention and focus, so daylight white is usually the preferred choice for many people.
  • Safety Certification: You should always buy T8 LED tube lights that have a UL or ETL certification. This means that the tube lights have passed the quality and safety standards of the Underwriters Laboratories or the Intertek Testing Services. These certifications guarantee that the tube lights are safe to use and reliable. However, you should be aware that certified products are usually more expensive than uncertified ones.
  • Energy Savings: You should also look for T8 LED tube lights that have a DLC certification. This means that the tube lights have met the energy efficiency and performance criteria of the DesignLights Consortium. These certifications qualify you for rebates from your utility provider in many cities. You can also save money on your electricity bill by using less energy.

4ft T8 Light Bulbs: Your Complete Tube Guide (3)

Differences Between T5, T8, and T12 Tubes

Fluorescent linear tubes, or fluorescent lamps, are usually grouped according to their shape, wattage, and diameter. As the "T" in the name indicates its tubular shape, the digit next to it denotes the size of its diameter. For instance, the T5 is a tubular-shaped tube whose diameter is five-eighths of an inch. The T8, as we have already seen above, is a tube lamp with a one-inch diameter.

The T12, on the other hand, is an older-generation fluorescent bulb that generates light through electromagnetic induction. This method of generating light is considered less efficient than the newer electronic-based circuits. Both the T5 and T8 tubes generate light through advanced electronic circuits. They are also available in standard 2, 3, 4, and 5-foot lengths. The main difference between the T5 and T8 tubes is the considerably reduced size of the T5. They are 40% smaller than the T8. Despite their size, they can give out the same or sometimes more light than their counterparts in a smaller area.

Even though the T5 lights usually cost more than the T8 lamps, their maintenance cost is lower than other fluorescent bulbs. In addition to their ability to provide more light (lumen) than the other bulbs, such advantages translate to long-term cost savings on residential and commercial projects.

Benefits of T8 LED Lighting

For a very long time, the cost of LED tube lights discouraged people from embracing them. However, with the advances in LED technology, they have become more affordable, making them easy to acquire and install. Apart from energy savings, less heat emission, and reduced load on the HVAC system, these led fixtures are also controllable. They offer more design flexibility since they are more compact.

The following are additional benefits associated with the installation of T8 LED lighting:

  • Dimmable – Dimming fluorescent lights has always been difficult and has baffled innovators for many years. Some fluorescent lights are not dimmable at all. Fortunately for modern-day users, LEDs dim easily.
  • Directional – With LED technology, you can easily direct light exactly where you want it. You can avoid diffuse light spread over a large area by opting for T8 LED lighting.
  • Work Well With Controls – Occupancy sensors and other control systems are easily integrated with LEDs.
  • More Energy Efficient – T8 LEDs are way more energy efficient than linear fluorescent lighting (LFLs).
  • Better Lighting Quality – Unlike LFLs, LEDs do not flicker. Additionally, they give light in a wide array of colors.

About the Author:Dara Greaneyis founder and CEO of LED Light Expert with deep expertise in LED fixtures and Light design.LinkedIn,WikipediaorTwitter. Editing byDavid Peguero.

About us: See ourAbout uspage for more aboutLED Light Expert.








Previous Post

Next Post

Welcome to our Blog. Feel free to message us on content you want to see.



Recent Posts


Ooop! The email you entered is not valid.

WooHoo! You subscribed successfully. Check Your Email to Complete Signup

Ok! You're unsubscribed.

  • Stay Connected
4ft T8 Light Bulbs: Your Complete Tube Guide (2024)


What does T8 mean in tube light? ›

What Are T8 Bulbs? T8 bulbs are a more popular form of LED tube used across various industries and buildings. The “T” refers to its tube-shaped characteristic, and the “8” refers to its diameter in eighths of an inch. In short, a T8 bulb is an LED tube lamp that measures one inch across.

How many hours does a T8 fluorescent bulb last? ›

A T8 bulb is considered end-of-life at 60% of its light output, which equates to roughly 14,400 hours.

What happens if you put a T8 bulb in a T12 fixture? ›

As far as safety is concerned, you can exchange them. If you place T12 tubes in a fixture with a T8 ballast, you will wear out the ballast and have to replace it. If you place T8 tubes in a fixture with a T12 ballast, then the tubes will have a shorter life due to a higher current through the tube.

What is the pin spacing for T8 bulbs? ›

T5 lamps have a G5 base (bi-pin with 5 mm spacing), while T8 and T12 lamps use a G13 base (bi-pin with 13 mm spacing).

What is better LED or T8? ›

The study compared the costs of six replacement options — one fluorescent and five LED — for linear recessed lighting systems and found that LED products were 18%-44% more efficient than T8 fluorescent lamps.

What is the lifespan of a T8 LED tube light? ›


T8 LED: A typical T8 LED bulb can last anywhere between 50,000 to 100,000 hours, which means less frequent replacements and additional savings in the long term. T8 Fluorescent: These usually have a lifespan of around 30,000 to 50,000 hours, significantly shorter than LEDs.

Are T8 fluorescent bulbs being discontinued? ›

T5 & T8 fluorescent and compact fluorescent tubes have been phased out. In 2023, T5 and T8 fluorescent and compact fluorescent lamps (CFLs) were phased out in accordance with the European Commission's Ecodesign and RoHS Directives.

Can you replace T8 fluorescent with LED? ›

These LED tubes are the newest, easiest to install and most expensive. They work with any kind of existing technology – whether it is T12 (Magnetic Ballast) or T8 (Electronic Ballast). To install them all you need to do is take the old fluorescent tube out and install the LED tube in its place.

How do I know if my T8 bulb is bad? ›

If the bulb is completely black or discolored, it's definitely dead. Checking how the bulb lights up: If the tube takes a long time to warm up before turning on, it might be on its way out. If the tube flickers constantly, that's another indication of a failing bulb.

What is better T12 or T8? ›

Energy Efficiency: T8 fluorescent lights are energy-efficient, offering improved efficiency compared to older T12 models. While not as efficient as T5 lamps, T8s still provide substantial energy savings and are widely adopted for general lighting needs.

How do I know if my ballast is T8 or T12? ›

T8 = 1-inch diameter. T12 = 1-1/2-inch diameter.

Can you use a T8 LED bulb without a ballast? ›

Most T8 LED tubes do not need a ballast.

So, if you are going to install a T8 LED tube light, it will require a ballast bypass unless you choose a ballast compatible T8 LED tube. T8 4ft LED Tube/Bulb - Glass 18W 1800 Lumens 5000K Clear, G13 Base, Single En...

Are all T8 fluorescent bulbs the same? ›

T8 LED tubes come in a variety of color temperatures (CCT's) and wattages so clients can get both the right color and light output for the task at hand.

Are all T8 bulbs the same length? ›

In addition to the common 4-foot length, T8 lamps are also available in 2-, 3-, 5-, and 8-foot lengths and in several U-shaped sizes.

Are all T8 bulbs the same size? ›

Fluorescent T8s

T8s are 1-inch diameter fluorescent tubes, and they are the most prevalent of all fluorescent tubes. Four-foot T8s, in particular, are used everywhere – in hospitals, commercial office spaces, schools, retail spaces, warehouses... everywhere.

What is the main difference between a T8 and T12 light tube? ›

T12 vs T8 Fluorescent Tubes

The main difference between 8ft T8 bulbs and 8ft T12 bulbs is the tube's diameter. T12 tubes are 1.5" in diameter while T8 tubes are just one inch. All other things—socket sizes, lengths, distance between pins—are the same.

How do I know if my light is T8 or T12? ›

This number is the numerator in a fraction where the denominator is 8 and the length is in inches. For example, with a T12, the diameter is 12/8, or twelve eights of an inch. Another way to say this is that the diameter is equal to 1.5 inches. For a T8, the diameter is 8/8, which is equal to 1 inch.

What is the difference between T8 and T12 lights? ›

T12 lamps have a diameter of 1 ½ inches (or 12/8th of an inch.) T8 lamps are fluorescent lights one inch (or 8/8ths) in diameter. T5 lamps are 5/8th in diameter.

Top Articles
Latest Posts
Article information

Author: Manual Maggio

Last Updated:

Views: 6483

Rating: 4.9 / 5 (69 voted)

Reviews: 84% of readers found this page helpful

Author information

Name: Manual Maggio

Birthday: 1998-01-20

Address: 359 Kelvin Stream, Lake Eldonview, MT 33517-1242

Phone: +577037762465

Job: Product Hospitality Supervisor

Hobby: Gardening, Web surfing, Video gaming, Amateur radio, Flag Football, Reading, Table tennis

Introduction: My name is Manual Maggio, I am a thankful, tender, adventurous, delightful, fantastic, proud, graceful person who loves writing and wants to share my knowledge and understanding with you.