Fluroescent Bulb Types & Differences

Fluroescent Bulb Types & Differences

T5 vs. T8/T12

T5 tubes are the latest series of fluorescent lamps. They are offered in standard or high-output (HO) options. There are many differences between T5 lamps and T8 or T12 lamps. 


T5 tubes are smaller than T8 and T12 tubes, which allow them to fit into smaller spaces. They are offered in sizes of 2-5 feet in length. T5 lamps are around 40% smaller than T8 lamps and almost 60% smaller than T12 lamps. 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). Because of a .625-inch bulb diameter, and a mini bi-pin base, the T5 lamp can be used in lower profile areas.

Output and Performance

The T5 lamp has a generally lighter output compared to the T8 lamp. The T5 is offered in color temperatures of 3000K, 3500K and 4100K. They have a color-rendering index (CRI) of 82 or 85, compared to the T8 with a CRI of 75 or 85. The T5 system provides its peak output at 35°C as opposed to the T8 or T12’s peak output at 25°C. This makes the T5 system a better choice in an output over temperature ratio, and a better choice to use for effective lighting in small, and low circulated spaces. With power ratings of 24, 39, 54, and 80, the T5 HO lamp easily beats the T8 or T12 system with over double the output. T5 lamps are generally rated for 20,000 hours, as compared to T8 lamps, which are generally rated for 24,000 hours.

T8 or T12 fixtures must be suspended over 2 feet from the ceiling in order to have effective light. This would be too low for many office buildings where ceilings are rarely high. With T5 lamps, suspension from the ceiling can be as little as 15 inches.

Mercury Content

The T5 lamp has a lower mercury content than T8 and T12 lamps, yet it performs with the same or greater efficiency. The lamp has a coating on the inside of its glass wall that stops the glass and phosphors from absorbing mercury. This barrier coating reduces the amount of mercury needed from approximately 15 mg to 3 mg per lamp. Since mercury absorption causes the lamp’s light output to depreciate over its life, the coating helps to keep light levels much closer to initial output (only a 5% depreciation in the first 40% of its life). The lower mercury absorption also keeps the light’s output as strong as its initial output, throughout its life.

T5 vs. T5 HO

The T5 and T5 HO are the same size, but have different outputs. The T5 has an output of 2,900 lumens, similar to the T8 output. The T5 HO has up to 5,000 lumens. With the T5 HO lamps, fewer lamps can be used on projects, which save money due to less maintenance. The high output and thinness of the lamps lets them be available for indirect and shallower lighting. Every T5 HO lamp requires its own ballast, but they are 10-15% less efficacious than normal T5 models. T5 HO ballasts also have many features such as a dimming function, or operating multiple F54 lamps.


T5’s are the first linear lamps to use electronic ballasts only. One T5 ballast can power one or two T5 lamps of any wattage, because they all run at the same current. Their different wattages have the same brightness, which stays the same with any length of the product.

Because of the lamp’s small size and high power, temperature can rise as the lamp dies because of less cathode emission material. This rise in temperature can cause the bulb wall to crack. The T5 ballasts have an “end-of-life circuitry”, which stops the bulb from cracking by shutting off the lamp when there is a rise in voltage.

T5 and T5 HO lamps are increasingly used in offices and industrial areas. The T5 HO system can be used in any area with a ceiling higher than 15 feet, including gymnasiums and warehouses. The T5 offers over 50% more energy saving then a 400 watt metal halide system.

You May Also Like... Other People Have Considered These Products...
View our T5 Fluorescent Bulbs collection.

T5 Fluorescent Bulbs

Get the perfect T5 fluorescent lamps for your lighting fixtures at Warehouse Lighting. We carry a wide variety of T5 lamps ranging from 4 to 54 watts. Order T5 fluorescent lights online from Warehouse Lighting.

View (44) Products
View our T8 Fluorescent Bulbs collection.

T8 Fluorescent Bulbs

Assorted lengths and wattages of fluorescent bulbs and lamps. Looking for low cost on your fluorescent lighting application contact us for assistance.

View (59) Products
Consider Watching These Videos as Well...
Retro a Fluorescent Strip Fixture to LED

Retro a Fluorescent Strip Fixture to LED 

When it comes to saving energy and money with your lighting solutions, LED technology is the way to go. If you already have fixtures in place that you are looking to convert for energy-savings, ...

Watch Video
What Are Fluorescent Lighting Electronic Ballasts?

What Are Fluorescent Lighting Electronic Ballasts?

Watch our What Are Fluorescent Lighting Electronic Ballasts? video. Our videos will educate you so that you can confidently purchase and install LED light fixtures, whether they are for a new insta...

Watch Video
Difference Between T5 and T8 Low Bay Fluorescent Lighting Fixtures

Difference Between T5 and T8 Low Bay Fluorescent Lighting Fixtures

Finding the right lighting solution for your location means comparing your options. When choosing between two types of lighting, there are many factors you may want to consider. For your l...

Watch Video