If you have ever had to spend any amount of time in a dingy office, or under the harsh glare of strip lights, you will know how uncomfortable and draining it can be.
In addition to being thoroughly demotivating, being in a poorly-lit environment for too long can cause headaches, eye strain and even illness. There is a growing body of research that proves exposure to natural daylight can demonstrably improve the wellbeing and productivity of building occupants in a wide spectrum of contexts, from offices and warehouses to schools and other public spaces.
The Benefits of Natural Light
Humans are programmed to be more active and alert during daylight hours, tiring as it becomes darker. Therefore, access to high levels of natural light will help to reinforce occupiers’ natural energy rhythms, making them feel more productive and positive during the day, and consequently sleep better at night. There are also many other health benefits associated with exposure to natural light which could help to improve mood and reduce absenteeism due to sickness, from encouraging the production of vitamin D, to easing the symptoms of seasonal affective disorder (SAD).
As a light source, daylight through windows and skylights is more diffused than artificial ceiling lights providing a more even illuminance of objects and people. Furthermore, as natural daylight contains all the colour wavelengths visible to the human eye, it is the ideal lighting source for colour rendition. Making the most of this ‘free’ light can also save up to 80% in artificial light demand, helping to minimise long-term running costs and maintain best practise in terms of a sustainable design under schemes such as BREEAM.
As the natural light levels are so important to a building’s function and success, it should always be considered from the outset of the design process. This will not only ensure that the type of windows and skylights work with the wider architectural vision for the project, but also that they will provide the adequate balanced daylighting required.
Natural light is extremely variable and requires careful management. Whilst artificial lighting can help to meet the demand in times of low light, excessive levels of sunlight can cause disruptive glare. This often results in occupiers counteractively having to pull down the blinds and turn on the lights. Similarly, too much direct sunlight can cause uncomfortable ‘hotspots’ in the room below.
Windows are the most obvious point of entry for natural light to enter a space. However, used alone, they are unlikely to provide a uniform distribution of light— particularly in deep rooms or central areas with limited external walls. Moreover, if the building is in a built-up area, direct light from the sky may be obstructed. Therefore, a daylighting scheme that uses a combination of windows and skylights should be implemented to obtain the quantity and quality of light needed.
The Right Materials
Recent advancements in rooflight technology has focused on refining their often-contoured shape to enable it to capture more light at low sun angles, such as in the early morning or late evening, regardless of orientation. In addition to having aesthetic merit, the carefully-honed designs ensure that spaces are adequately illuminated for more hours of the day than standard rooflights, thus increasing the occupants’ exposure to daylight and saving more in artificial light demand.
The polycarbonate glazing itself has also undergone many developments to guarantee excellent levels of light transmission for the lifetime of the product. As a material, polycarbonate does not filter out blue spectrum light— the colour temperature associated with morning when we are most alert. Other traditional or industrial rooflight materials can yellow over time, blocking out the beneficial blue light waves and distorting the visual environment. Some of the latest rooflights also incorporate layers containing microscopic prism structures which scatter the beams of sunlight, eliminating glare and resulting in a soft natural light ideal for creating a lively atmosphere. Climate control glazing options, including ultra-violet (UV) and infrared (IR) blocking particles, can provide additional protection against solar heat gain, helping to keep spaces well-lit and thermally comfortable.
To maximise the energy and cost savings that can be achieved in each application, precision-engineered rooflights can be used in conjunction with low-energy intelligent lighting solutions. With a combination of smart dimming controls, motion detection and daylight harvesting, these systems can reduce lighting costs by up to 90% by only providing the exact quantity of electric light required in periods of no or low ambient light. Designs are also available with a motorised opening and closing mechanism to offer daily aeration and ventilation, in addition to exploiting daylight.
Light the Way
As awareness of the positive effect daylight has on our productivity, health and happiness grows, so too does the demand for buildings which can effectively exploit it. By applying the latest technologies, specifiers can ensure both new and existing buildings are effectively lit with natural light for longer periods during the day, saving energy and improving the comfort of occupants.
For further information and technical support please contact Kingspan Light + Air.