What is daylighting?
Lighting businesses and commercial spaces with daylight facilitates highly efficient work environments that also cost less money to run, since less artificial light is required.
Daylighting is the practise of placing windows, skylights and light shelves within a building so that during the daytime, natural light provides effective internal lighting. In addition, using reflective, light-coloured surfaces within the building helps to diffuse the light even better, further enhancing the area that you can light with this technique.
Why is daylight so beneficial?
Daylight is free!
For the business, using daylight to light a space means that less artificial light is needed to illuminate the space for tasks to be completed. During the winter months, when there are less daylight hours, the need for artificial lighting to complement daylight will increase, but regardless of this, less artificial light will be needed so it should result in big energy savings over the long term.
Major health benefits for employees
One of the major advantages of daylight is for your employees, and its ability to better regulate the circadian cycle. Our internal circadian clocks regulate the timing of sleepiness and wakefulness throughout the day over each 24 hour period.
Exposure to daylight in the morning helps stimulate wakefulness through excretion of cortisol – a natural hormone that helps to heighten memory functions as well as making us more alert. Exposure to daylight in the morning also represses the production of melatonin, which is associated with sleep onset and normally gets produced when it goes dark. A better-regulated circadian cycle leads to better sleep patterns and increased productivity, which not only is great for the individual, but it also benefits the business.
Better colour rendering
Another benefit of daylight is the level at which it renders colour. Colour rendering is the ability of a light source to give good colour representation of the colour it is illuminating. This is measured on a scale of Ra 0 – 100, with 100 being the best. Daylight comes in at Ra 100, so this makes it far better than any artificial light.
Another benefit of daylighting is the continued operation of the business during power outages, since the workplace won’t suddenly fall into darkness. In addition, the improved mood of employees who have access to more interesting external visual stimuli.
Why is daylighting becoming more popular?
Daylighting has increased in popularity in recent years, not just as a result from the green movement. The improved performance of glazing (double or even triple glazing are far more energy efficient than traditional single glazing), thus buildings can have an increased proportion of glazing and need not worry about the reduced energy efficiency as much. In addition, since energy costs are continually increasing, ‘easy wins’ to lower energy consumption are being adopted to ensure companies can increase their bottom line.
How could your business benefit from daylighting?
Ideally, daylighting is taken into consideration when the architects are designing the workplace, however measures can be retrofitted within the building to help improve the amount of daylighting entering it.
Obvious actions include installing additional windows in to the fabric of the building; however it is important that these are still strategically placed since glare from direct sunlight can inhibit workplace efficiency.
Ideally light is bought into the office high up, through the installation of skylights and light shelves. If bought in through windows, the light will need to be diffused to help mitigate the glare issue. Once the light is bought in, light coloured interior surfaces will help improve the coverage.
It is important to have lighting controls that manage the total level of lighting within the building, so they can dim artificial lights when there is sufficient daylight.
The issue of increased solar gain
Apart from glare, one of the issues with increased daylight entering the building, especially during the summer months, is solar gain, where the glazing acts to magnify the amount of heat in a space. If the amount of solar gain in a space increases as a result of trying to implement a daylighting solution, then the cost savings associated with being able to use less artificial light is offset by the increased cost of office cooling.
Smart glass (electrochromic glass) is used in some workplaces, and the advantage of this is that it will have different light transmission properties when a voltage is applied. This means that it can control the amount of light (and heat) entering the building at any time, so helps mitigate the solar gain and glare issues, although this is obviously far more expensive to implement at the moment.