Fluroescent Bulb Types & Differences

There are three common types of fluorescent light types: T5, T8, and T12 tubes. T5 tubes are the latest series of fluorescent lamps. They are offered in standard or high-output (HO) options. They differ from T8 and T12 bulbs in size, efficiency, and more, making them a common choice for modern lighting. While T8 and T12 lamps are still widely used, T5 tubes are a more advanced solution for those looking to upgrade their lighting systems. Here is how T5, T8, and T12 differ from each other:

Size

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.

Energy Efficiency & Cost Savings

Each type of fluorescent lamp has different wattage requirements and lumen output, which impact electricity costs for commercial and industrial facilities. Here’s a breakdown of the energy consumption for each type:

• T5 Lamps – The most efficient option, with a higher lumen output per watt than T8 and T12 lamps. T5 HO lamps provide up to 100 lumens per watt.
• T8 Lamps – A balance between T5 and T12, T8 tubes typically deliver 80-90 lumens per watt.
• T12 Lamps – The least efficient option, T12 lamps consume more energy while delivering only 50-70 lumens per watt.

Switching from T12 or T8 to T5 can save a significant amount of money over time. Consider this example:

A four-lamp T12 fixture consumes 160 watts (40W per lamp), while a four-lamp T5 fixture consumes 108 watts (27W per lamp). If the lights run 12 hours per day, 5 days a week, that’s 9,984 kWh per year for T12 vs. 6,739 kWh per year for T5. At an average electricity rate of $0.12 per kWh, switching to T5 would save $389 per year per fixture.

Applications & Uses for Each Type

Choosing the right type of fluorescent lamp depends on the lighting needs of a space, ceiling height, and energy cost goals. While T12 lamps are being phased out, T8 and T5 are still common in commercial, industrial, and institutional settings.

T5 Lamps are best for high-ceiling commercial and industrial spaces, including the following:

• Factories
• Gymnasiums
• Sports Facilities
• Warehouses
• Distribution Centers
• Manufacturing Plants
• Retail Stores
  

T8 Lamps are best for medium-ceiling commercial spaces with a need for efficiency and affordability. Here are some places T8 tubes are common:

• Offices
• Schools
• Hospitals
• Laboratories
• Parking Garages
  

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.

Which Fluorescent Light Type is Best?

When selecting a fluorescent lamp, consider efficiency, output, fixture compatibility, and long-term costs. T12 lamps are outdated and being phased out due to their high energy consumption and lower lumen output, so the real choice is between T5 and T8.

T8 lamps balance efficiency and affordability, making them a common choice for offices, schools, and parking garages. However, if you want to maximize efficiency, reduce costs, and future-proof lighting, T5 lamps are the best choice. With a higher lumen output, smaller size, and less energy consumption, T5 tubes outperform T8 in most commercial settings.

If you're upgrading your lighting system, switching to T5 offers the best return on investment in terms of efficiency, performance, and cost savings over time.

Choosing the right fluorescent lighting can make a significant impact on energy efficiency, performance, and long-term cost savings. Whether upgrading an existing system or installing new fixtures, selecting the best option ensures optimal lighting for your space.

Browse our selection of high-performance fluorescent lighting at Warehouse Lighting today.