Neon compared to other light sources*

Some very common questions may appear when buying a light source: how does this lighting perform compared to others? What are the advantages and disadvantages? Which one should I choose? Therefore, in this article we intend to explain the main differences, advantages and disadvantages of a neon light source compared to other popular mediums. The idea is also to help you decide which kind of light source will fit to your needs.

Identifying your priorities

We see that the first and most essential step on deciding which light medium to use is to define your own criteria and needs. When buying anything nowadays, it's almost impossible to tell which one is the best when comparing brands or similar products unless you specify what's your criteria. You might compare only price, quality, durability, features and so on, or a combination of these items as well as sort them differently depending on your project and requirements.

Neon light sources can be used to multiple purposes including interior lighting, signs and others. In this case we will focus on neon signs and compare to other light-based signs. Therefore, we consider important to analyze and understand the following criteria when choosing your sign:

• Price
• Durability
• Maintenance
• Efficiency (energy consumption)
• Appearance

Thus, we will be able to compare neon signs with other types of signs according to these criteria. Currently the most popular sign type is made of LED's. So, we will focus our comparisons between neon signs and LED signs. Then, it's up to each customer to define what is the importance of each of these topics before buying the sign.

Price

Neon signs use very simple and cheap raw materials (glass and gas) that will be able to generate light with electricity. LED's are a more recent technology and use a more complex fabrication process to also be able to generate light through electricity. However, each neon sign has to be produced by hand. That means it requires hand work to heat up and bend each glass tube according to the desired design. This requires human labour and production time which is more expensive. LED's can be more easily produced and put together by machines and quick hand work.

In the end, the prices for a similar sign made of LED or neon can be comparable, even though normally the LED sign can be 10% to 15% cheaper.

Durability

Both LED and neon signs can run for a very long time (~10 years) but it always depends on the usage and environment conditions. The lifetime of these light sources is usually counted on hours of glow, so the less you use them, more they will last. 

LED's and neons can have a comparable lifetime but they both can present a tiny reduction of its initial glow as the time goes by. It's still very common to see neon signs in the streets which are running for decades now.

The difference can arise when comparing robustness in terms of breakage. As neon signs are made of thin glass tubes, it can be more susceptible to breakages due to shocks or impacts. LED signs can be far more resistant to this kind of breakage. 

Maintenance

As said above, both LED and neon signs can have a very long last lifetime. However, at some point this lifetime comes to an end. Then it's time to give it maintenance or replacement. 

LED's cannot be maintained in order to present the same glow as before. They must be replaced. Some signs could be built in a way that you replace only the LED itself while some others might require that you replace the whole sign.

Neon signs on the other hand might require just a re-filling process of its interior gas. So, you can still use the same sign with the same glass, that just by re-filling its gas it will shine as much as its first day.

Efficiency (energy consumption)

One of the reasons LED's became so popular is due to its high efficiency compared to other light sources that already existed, including neon lights. The cost saving for energy consumption can vary sometimes more than 50% but it depends also on brightness, type of electrical transformer, among other factors. 

Many differente sources present different facts and opinions with regards to efficiency of neon light sources compared to LED's. Therefore, we at sygns decided to prepare a testing scenario and compare these two light sources.

To be able to precisely measure the light emission of a neon tube it's necessary to place it in a special room with multiple light detectors at every possible direction so one is able to capture virtually every emitted ray of light. Our purpose here was however to estimate the relation of power consumption vs light emission of a neon tube when compared to an LED source. Thus, the following experiment was built:

A box filled with reflective foil internally had two holes facing one another. On one side a light measuring device was placed whereas the light source stays on the other side. One of the main problems when comparing an LED source with a neon light source is the direction of the rays. LED's spread the light differently depending on it's construction. It can be really focused as it can be a bit more diffuse. In virtually any case, an LED is not able to spread the light equally through the 360° around it like a neon tube would do. Therefore, it becomes hard to compare their efficiency since the light rays can be more or less concentrated.

To try minimising this effect, first we covered most of the neon tube's surface leaving just a section whose length was the same as the LED strip:

Next, we covered also part of this open section, leaving just the equivalent of 1/4 of a complete turn of the neon tube (90°):

The idea is to block the light emissions from all over the tube and leave just a window whose surface can be compared with the LED strip surface in terms of size and emission direction. Then, after measuring its emission, one can easily multiply the area of this window by a correction factor to estimate the emission of the whole tube in every direction and finally compare the energy consumption with the LED source.

To be able to match the power consumption of both sources we used a dimmable transformer for the neon tube. After adjusting the current level to match the LED consumption, we let it run for a while in order to stabilise the values. The light emission of the LED decreases a bit after the initial minutes whereas the neon tube increases at it heats up.

The following table shows the behavior of both light sources after turning on (cold start) and after stabilising (stable):

We can see that both sources were consuming a very similar amount of energy but the luminosity of the neon tube increased whereas the luminosity of the LED strip decreased. Naturally the amount of LUX coming from the neon source was much smaller as most of its surface was blocked as explained above. Now it's only necessary to compensate the area difference on the neon tube to find the actual luminosity of the whole tube. The whole neon tube has a length of 74cm and the open section (as well as the LED strip length) is only 10cm long. That means we need to multiply our luminosity by 7.4 to compensate the length and then by 4 to compensate the other 270° of the round tube.

Making these calculations we find a total of 2.427,2 LUX being emitted from the whole neon tube which is clearly way more than the 970 LUX coming from the LED strip. As mentioned above, this experiment is a rough aproximation to analyse how much can we compare the efficiency of neon lights with LED lights. It's also important to notice that LED light sources today are more commonly used with the purpose of pure illumination whereas neon lights are often used for signage or decoration. That means, even if someone is not using both light sources for the same purpose, it's interesting to know in a fair comparison which light source can actually be more efficient in terms of simply converting electrical energy into light.

Finally, according to our experiment, the final table can be presented:

Appearance

The neon signs on the other hand became so popular decades ago not only due to its long-lasting time, simplicity of raw materials but also to its charming glow and vivid colors. Also, LED's are discrete elements while neons are continuous glass stripes. That means, to make a uniform continuous shinning surface whit LED's you either need to insert them behind a uniform translucid material or use a panel with several tiny LED's that can look continuous from the distance. However, it's very common to see these tiny dots on LED panels or irregular backlighting from translucid materials that carry LED behind it.

Another interesting point on neon signs is that the glass tube shines in every direction. That means you also have freedom to design signs that can be seen from every side, including 3D installations. To achieve similar result with LED's you would need to install many LED's facing different sides which could become a very complex structure, if possible to be built.

Nowadays we can find silicon or plastic tubes with inside LED's that simulate the neon appearance. However, often you can see their non-uniformity along the tube (as mentioned before) but also it only simulates neon signs that have solid colored glass tubes. The visual effect of a clear glass neon, which you see directly the shining glass inside, won't be possible to be reproduced by LED's anytime soon.

Conclusion

As mentioned in the introduction, it all depends on which criteria are more important to you. After analysing the above points, we understand that if your goal is exclusively save costs, you might go for LED signs. This includes many business owners that just want a simple cheap sign (easily replaceable) that also doesn't drain too much energy.

On the other hand, if you want to give your sign a special look, praising more for the artistic side, a neon sign is definitely the way to go. It carries not only the glamour of the retro signs but also the beauty of its handwork production that depends on an artistic execution. It is definitely no coincidence that they were the main option for many decades and even now with lots of other options for general lighting, including LED, they are still largely used and seen on most cities.