Circadian lighting in the smart home

For those reading this who don’t know of us, CEAV is an electrical slash smart home integrator specialising in lighting control. So, when new and exciting innovations start to gain traction in the lighting industry, we take great interest in them. Circadian lighting is one such trending innovation that we are incredibly excited by.

I think everyone would agree that the hype around circadian lighting has been building increasingly over the past few years. Like many other integrators, we didn’t want to be left behind, so we started researching and testing products we could eventually deploy on our projects. This article is the result of those efforts and showcases some of the fantastic solutions we discovered along the way. It also highlights some of the potential issues that can be encountered when trying to design and implement circadian lighting into larger projects.

I’ve wanted to write this article for a while because I’m sure many of you will have the same questions surrounding circadian lighting that we initially did. Therefore, in this article, I will attempt to answer some key questions, such as, what is circadian lighting? What solutions are currently available? Is the technology mature enough for large professional installations? And finally, as a smart home integrator, how can we integrate circadian lighting with the smart home systems we install?

Let’s get started...

What is circadian lighting?

Human beings follow a 24-hour cycle that affects physical and mental behaviours. This natural biological clock, or circadian rhythm as it is known, primarily responds to changes in light; a good example of this is that we sleep during the night when it is dark, and we are awake during the day when it is light. Other attributes such as energy levels, alertness and tiredness are also linked to our circadian rhythm.

Before the invention of electricity, our circadian rhythm was solely impacted by the cycle of the sun and the colour and intensity of the light that it emits. We’re all very familiar with this cycle; a faint red Sun in the morning, turning bright white in the middle of the day, before returning to a faint red Sun in the evening, including a spectrum of colours in between. Our sleep/wake cycle follows this cycle closely. However, since the advent of electrical lighting, we can now artificially produce and use light at different colours and intensities at whatever time we like. According to research, this can affect us in various detrimental ways, including our sleep patterns, eating habits and alertness levels.

Circadian lighting attempts to solve this by mimicking the natural colour temperature and intensity of the Sun throughout the day by using specialised light fixtures with the primary aim of improving our well-being, comfort and productivity.

The colour ‘temperature’ is measured using an industry-standard scale called the Kelvin scale. The higher the Kelvin rating the bluer the light; conversely, the lower the Kelvin rating, the redder the light.

Kelvin scale

Using this scale, a circadian lighting system should output light at around 2700K in the morning and automatically adjust itself throughout the day, up to a peak of 6000K at midday, before adjusting itself back down the scale to 2700K in the late evening. Ideally, this should be done automatically by the lighting system and without any input from the user.

What solutions are available?

It was a relatively recent project which opened our eyes to the difficulty and technical aspects you encounter when trying to implement circadian lighting on a larger residential project. Sure, IoT solutions such as Phillips Hue have been available for a long time, but what if you’re an integrator and trying to deliver a more reliable solution that doesn’t rely on wireless technologies for control?

A quick Google search for ‘Tuneable downlights’ will yield plenty of results, but when you dig a little deeper, you’ll find that most options require a propriety hub, mobile app or remote control to change their colour output. These solutions are not ideal for larger homes and usually rely on Wi-Fi or RF to communicate with each individual lamp which, in the long-term, is not a consistently reliable solution. They’re also very difficult, or in most cases, impossible, to add to a broader lighting control system.

In practice, the best way to reliably control a light fixture is always to use a wired control method. The most popular of these methods in residential installations would be phase dimming, 0-10v dimming, DALI control or DMX control. Phase and 0-10v dimming will only provide the ability to control the brightness of a fixture, which eliminates both from being an option. Therefore, this leaves us with DALI or DMX being the only advanced options left to control tuneable lighting.

After researching further, we found that some premium manufacturers are already producing fully tuneable light fixtures using the standard DALI and DMX protocols. Manufacturers such as John Cullen, Synergy Lighting and Crestron all have products available today or coming very soon. We also found that there are many new DALI controllers on the market with the ability to control the brightness of a fixture as well as its colour. These DALI controllers are referred to as DALI Type 8 controllers as opposed to the older Type 6 controllers that did not have this ability. DALI type 8 controllers are available from manufacturers such as Gira, Jung, Crestron and Lutron.

Crestron's range of tuneable white light fixtures

Our success in discovering the previously mentioned downlights only brought to our attention the limited choice currently available. We found a small, but very good, selection of tuneable downlights, track lights, LED strips and linear LEDs. Unfortunately, we weren’t so lucky to find DALI-controlled tuneable pendants, wall lights, marker lights or uplights. For the time being at least, and until circadian lighting becomes more popular, full-scale deployment of circadian lighting systems where every light fixture in a property is tuneable is something for the future. Manufacturers will need to start producing tuneable DALI versions of their fixtures before it really takes off.

Integrating circadian lighting with a smart home system

Okay, so you’ve invested in tuneable lighting, and now you need a way to control it; what options are available? Well, I would say the control side of things is pretty much-taken care of and is in a very good state. All the big hitters in the premium smart home industry have recently included the ability to adjust tuneable lighting directly from within their systems, including Crestron, Control4, Rako, Gira and Basalte. Apple’s HomeKit and Google Home have also recently added this feature to their platforms which have become increasingly popular with our customers. Depending on the chosen smart home system, both wired and wireless lighting solutions can be integrated, but in some cases, additional drivers and/or licenses will need to be purchased. 

Smart home systems can be used to manually control the temperature of the light or used to automatically change the lighting based on the time of day or through the use of lighting scenes. Below are some screenshots of Crestron Home's implementation of circadian lighting as seen on their iPhone app. 

Crestron Home's mobile app to control circadian lighting

Conclusion

Circadian lighting is here to stay, and we, like many others, think it will be a standard feature in the years to come. For a small home, it’s a no-brainer to use a wireless system like Casambi to provide you with an advanced lighting system with wireless lamps/fixtures which are all tuneable. However, in larger homes with premium decorative pendants and wall lights, it would be a more difficult proposition to provide a complete circadian solution at the current time. That’s not to say it is impossible, but specific planning and bespoke solutions would need to be provided.

Luckily for you, this is where CEAV can step in and help! We have been supplying and installing incredible lighting control systems for over a decade. For a free consultation and quotation for your next project, feel free to reach out, and a member of our friendly sales team will be happy to help.