Neon signs—how they work, how they perform and are there alternatives?

 

On this page, we explore some of the technical aspects of neon signs, including:

  • how traditional neon works
  • how flexible they are in terms of functionality—can it change colour, or dim?
  • what kind of performance you can expect from neon

We also tell you about alternative technologies to neon, namely LED acrylic neon lights (also known as “faux-neon”). This is the technology used in NeonPlus®.

Quick links:

How do neon signs work?

Can neon signs perform different lighting functions?

Are there issues with how neon signs perform?

Are there alternatives to using neon?

How do neon signs work?

  1. Examine any neon sign and you’ll see it consists of a glass tube (or tubes) shaped into a particular design.
  2. At either end of the tube is an electrode—one negative, one positive.
  3. Inside the tube is a small amount of neon gas. Neon is a noble gas, meaning it only undergoes chemical reactions under high-energy conditions, like when it comes into contact with electricity. Otherwise, it simply drifts through the tube without doing anything.
  4. Apply an alternating current to the electrodes and the electricity creates enough energy for the neon atoms inside the tube to separate. Some shed electrons to become positively charged ions, which fly towards the negative electrode.
  5. The free electrons have a negative charge and are drawn towards the positive electrode at the other end of the tube.
  6. As the neon atoms, ions and electrons bounce around the tube, they collide with each other, increasing in energy.
  7. When the ionised atoms recapture their electrons to become neutral again—returning to their original energy level—they release a photon (particle of light), which is what causes them to give off a coloured glow.
    Cutting off the electricity supply to the sign returns the neon atoms to their normal inert state.

Can neon signs perform different lighting functions?

Changing colour

Traditional neon signs can’t change colour

When charged with an electrical current, neon is capable of generating only a reddish-orange light—it will never glow blue or green, for example.

The shade of red or orange it produces depends on how energised the neon atoms inside the glass tube become when electricity is run through it. See How neon signs work above.

To create a sign that glows in other colours means using different gases, as these react differently when combined with electricity. You can also combine them with neon inside the glass tube.

The table below shows which gases produce which colours.

Type of gas used

Colour of light

Neon

Red or orange-red

Argon

Blue or lavender

Helium

Orange or yellow

Krypton

Grey or green

Xenon

Blue or grey

Radon

Purple

Mercury

Blue

Hydrogen

Red

Other ways to achieve different-coloured lights include:

  • coating the tubes in phosphor or a fluorescent powder—these will glow a certain colour when energised
  • using coloured fluorescent lights inside the tube
  • using tinted glass

LED neon signs CAN change colour

There are two main ways in which LED neon signs like NeonPlus® can change colour.

RGB LED

The first and more common option is to use a RGB (red, green and blue) LED chip. This has three small diodes within it, one of each colour. Connecting an RGB controller allows the user to change the intensity of each red, green or blue diode to achieve a wide range of colours.

Digital LED

This too uses red, green and blue diodes inside an LED chip. However, the chip also has a ‘driver chip’ attached, which allows the user to control each LED independently. Because the controllers are more advanced, they are able to produce very complicated patterns and designs.

Dimming

Traditional neon

It’s possible to dim a traditional neon sign, but you’ll need a dimmable neon transformer that’s sized according to the voltage and current your sign uses.

Neon signs require low current and high voltage to work, so it’s vital that you choose a transformer that matches them. DO NOT use an off-the-shelf lamp dimmer, as these regulate only voltage and not current. Using one of these could cause serious damage or even a fire!

Bear in mind that you won’t be able to dim the neon light completely—the lowest you’ll achieve is likely around 10% brightness.

LED neon

There are two ways to dim an LED neon sign like NeonPlus®:

Low-voltage rotary or digital dimmer

These simple controllers are wired in on the low-voltage side and reduces the voltage coming from the power supply unit (PSU) to the LED.

Dimmable power supply unit (PSU)

Attaching one of these to a leading-edge or TRIAC rotary dimmer (the same kind of dimmer you’d use to dim the lights in your living room or dining room) reduces the voltage within the PSU. This, in turn, lowers the output voltage and dims the lights.

This is a good option if you want to run the lighting through a lighting system, like in a shopping centre or theatre. There are a number of different dimmable PSUs whose use depends on the circumstances, but they essentially dim or control the light in the same way.

Both of the above options allow the user to dim the LED to 0%, usually while keeping the light consistent and without any flickering.

Are there issues with how neon signs perform?

Do they burn out?

Unfortunately, burnout is a fairly common issue with neon signs. Either the whole sign or part of the sign will stop glowing, and this will generally be for one (or maybe more) of the following reasons:

  • Wires burning out—most burnouts involve the high-voltage wiring that connects the neon glass tubes. If they overheat, they can burn out and cause the sign to stop glowing.
  • Transformers failing—if something goes wrong with the transformer that allows the neon sign to illuminate, the sign will simply stop working.
  • Gas tubes failing—if the electrodes on either end of a glass tube don’t function properly, sections of the tube might look dim or not light up at all.

Obviously, with LED faux-neon, there’s next to no risk of you having to return the sign to the manufacturer for burnout repairs.

Do they get hot?

Because of how neon signs work, the energy generated from atoms, electrons and ions colliding with one another inside the tubes can sometimes occur not only as light but as heat too.

However, whatever heat the neon sign does give off—particularly signs which incorporate quite narrow glass tubes—shouldn’t so be hot that it’s unsafe to touch. For this reason, you shouldn’t have any concerns about neon signs possibly being dangerous or causing burns.

Many neon sign manufacturers cover the electrodes at either end of the glass tubing with rubber caps. These caps protect the bare wires, stopping them from getting wet and preventing people from touching them and possibly getting burned.

Are they dangerous?

No. Neon signs are completely safe to use, as long as they have been manufactured correctly and are kept in good condition.

The risks most commonly associated with neon signs concern:

  • the use of noble gases—it’s said these can be harmful if they leak into the air through a damaged tube, but signs are designed to turn themselves off if damage does occur
  • the glass tubes getting hot—they might give off some heat, but not enough to burn

Neon signs in any colour other than red contain a very small amount of mercury—a poisonous substance—as this is how they achieve their particular tint of light. As of April 2019, there are steps in place to ban the use of mercury in neon signs, which, if enforced, would limit signs to red, pink, amber or purple colours only.

However, the fact is that neon signs have been around a long time and, these days, are designed and manufactured with all of the safety considerations in mind, including the need to meet strict quality standards and to use mercury safely and responsibly.

How much electricity do they use?

Neon signs are quite energy-efficient and consume far less power than you might think given how brightly they glow. Most modern signs come equipped with a 240v transformer and use about the same amount of electricity as a single domestic light bulb (60W–100W).

A typical LED neon sign will consume only 15%–20% of the power traditional neon uses on a similar job, while fluorescent and incandescent lights will use significantly more.

How long do they last?

The lifespan of a traditional neon sign depends on how frequently it’s used and how well it’s cared for. Most neon signs are expected to last between eight and 15 years, although many continue to function for much longer than that.

Leaving a sign switched on for prolonged periods can shorten its lifespan, and leave it at risk of overheating or sustaining damage from electrical surges.

Do neon signs have to comply with certain regulations?

Yes. All neon signs must conform to BS EN50107, a British Standard that dictates how luminous discharge tube installations (such as neon lights) must be manufactured.

Neon signs must also meet the requirements of the IET Wiring regulations, another British Standard known as BS 7671 that sets out specifications for how these types of electrical installations should be wired.

Before you buy a sign, always check that it has been stickered and marked to show that it complies with the necessary standards.

Businesses have a legal duty to carry out fire-safety risk assessments regularly and take measures to limit any risks as much as possible. A neon sign would be checked as part of any assessment but likely deemed to carry little risk in terms of potentially causing a fire.

Are there alternatives to using neon?

Yes. The main alternative is LED neon—also called “faux-neon”—which uses LED technology to replicate the look of traditional neon, without any of the drawbacks.

Below, we look at the differences between neon and LED, and compare the pros and cons of both types of lighting.

Neon vs LED neon

The clearest difference between the two is in how they generate light.

Where neon relies on a chemical reaction between gases and an electrical current, with LEDs (light emitting diodes, in full) the reaction occurs when electrons pass through a semiconductor, which is typically a material known as aluminium-gallium-arsenide.

When used in signs, the LEDs are placed in close proximity to each other so they produce a steady source of light similar to the effect of neon gas glowing inside a glass tube.

Neon—pros and cons

The table below shows the benefits and drawbacks of choosing neon signs.

Pros

Cons

  • Many people prefer the warm glow of neon to the more solid LED light
  • Slightly longer expected lifespan
  • Maintenance is fairly simple—gases refilled every so often, glass tubes might need to be replaced
  • No chance of being damaged by power surges
  • Needs significantly more power to run than LED
  • Can be hot to the touch
  • Danger of broken glass or noxious gases leaking
  • Light can’t be altered in any way once in operation—limited dimming, no colour changes
  • Prone to breaking while being transported and installed
  • Impending restrictions on how neon is manufactured

LED neon—pros and cons

The table below shows the advantages and disadvantages of opting for LED neon signs like NeonPlus®.

Pros

Cons

  • Uses far less power than neon
  • Doesn’t give off heat
  • Lower running costs for large displays
  • More friendly to the environment—no potentially harmful gases
  • Brighter and more consistent light than neon and can be seen from further away
  • Can be dimmed, flashed or change colour
  • Much more robust than glass
  • Designed to run for between five and 10 years
  • Can be safely couriered all over the world
  • Simple to fit and wire together
  • Able to replicate brand logos exactly
  • NeonPlus® is the only LED neon of its kind that’s CE-certified and championed by BSI
  • Some people find them less appealing to look at
  • LED light needs to be diffused as it can be harsh on the eye
  • Maintenance can be costly, if the acrylic housing has to be replaced or engineers need to fix LEDs themselves
  • Electronics can be damaged by power spikes if no surge protection is in place

PRACTICAL INFORMATION