T5 Fluorescent Tubes – Frequently Asked Questions

What is a T5 and how is it different from a T12 or T8?

A T5 is a type of fluorescent tube. It differs from a T12 and a T8 in its diameter. All T5s are 5/8ths of an inch (T8s are exactly 1inch thick and T12s are 12/8ths or 1.5 inches thick). T5s are 16mm in diameter making them the thinnest fluorescent tube out of the three.

T5s are also much more energy-efficient than T12s and T8s. They have an A-class energy efficiency rating. They are considered to supply high quality of light in terms of Colour Rendering Index (CRI) and quantity of light measured in Lumens per Watt.

How do I know I need a T5?

If you want to save money on your electricity bills and the lights aren’t going to be used in extreme environments then T5s may suit you best. If you have previously used T8s or T12s you will have to upgrade your ballasts however as the smaller size requires a different fitting. If you’re considering moving from T12 to T8 it might be worth your while to take the bigger jump and just go straight to T5 to realise much greater efficiency.

What environments does the T5 perform well in?

Schools, offices, commercial buildings, emergency lighting, refrigerators and some factory settings. The more common T8s aren’t as well tested in extreme conditions like cold temperatures, whereas the T5 is a tried and tested solution.

How easy is it to upgrade my lights from T12 or T8 to T5?

If you want to upgrade your bulbs to T5s you will have to install new ballasts or use an adaptor as T5s are a bit shorter than the alternatives and also have a mini-pin base.

What type of ballast do I need for a T5 fluorescent tube?

Like T8s, T5s can uses electronic ballasts of electromagnetic ballasts. You will need a ballast specific to the size of T5 tubes though. Find out about electronic ballasts and electromagnetic ballasts on our T8 FAQs page.

Are T5s energy efficient?

Yes, T5s are extremely energy efficient. They are considered the best option in terms of energy savings out of T5s, T8s and T12s.

What is the diameter of a T5?

The diameter of a T5 is 5/8ths of an inch or 16mm.

What wattage do I need?

T5s come in various different wattages. To find out what wattage you need simply look at the current tube. It should have the wattage marked somewhere. If you can’t find this information check the ballasts for a marker or sticker. If you’re still unsure what wattage you need just give us a ring and we can help you find it: 0843 178 2828

What colour temperature do T5s come in?

They are available in a wide range of colours:

• 827 – extra warm white
• 830 – warm white
• 835 - white
• 840 – cool white
• 865 – daylight

Are T5 tubes dimmable?

As with any fluorescent tubes, T5 tubes can be dimmed so long as they have a dimmable ballast installed, which provides the control to dim the lights.

How long do T5 tubes last?

On average, fluorescent tubes last 30,000 hours.

How do I install T5 tubes?

Installing T5 tubes is relatively straightforward – but make sure you follow our step-by-step guide and safety tips to make the process as smooth as possible.

Do T5 tubes need starters?

You shouldn’t need a starter for modern fluorescent tubes like T5s – the control gear that runs them are high-frequency and do not require external starters.

Please note: the information in this article is provided as a guide only. We strongly recommend speaking to an electrician before attempting any electrical work yourself. Any links included in this article are for information purposes only and Lamp Shop Online does not endorse the websites linked to.