Improving Lives and Cutting Energy Costs with Natural Daylighting

Sustainability has become a major focus for all of society in the 21st century, and its popularity is only growing as global environmental concerns rise.

While the ‘greening’ of the world is a noble trend, it can be time-consuming to wade through all the info out there and determine what is not only good for the environment, but good for your bottom line, and more importantly good for your customer’s bottom line. Implementing natural daylighting in a building project is an easy way go green, contribute to earning LEED® credits, and gain a quick return on investment all at the same time.

For the many of you already integrating daylighting into projects – excellent work! Stick around though, we’ll get into some details so you can learn even more. For those who don’t know much about why natural daylighting is so important, be sure to read on!

What is Daylighting? 

Daylighting is the use of glazing (typically glass or plastic) to allow natural light into spaces, often replacing the use of artificial light. There are two main types of daylighting options; top lighting (skylights and roof lights) and side lighting, often referred to as ‘clerestory windows’. There is also shelf lighting, where a reflective shelf is added in front of the glazing for even more daylight. 

Traditionally, daylighting has been used in agricultural applications where electricity is unavailable or simply is not cost effective in areas such as loafing sheds, fertilizer storage buildings, and animal confinement structures. Today, in addition to those traditional agricultural applications, natural daylighting is often incorporated into high-end architectural projects, retail facilities, hospitals, schools, offices, warehouses, and other buildings. 

Energy Codes 

Energy codes are the driving force behind the green movement. See a few examples:

• ASHRAE 90.1 2010 places standards on energy efficiencies in building, except for low rise buildings. 
• ASHRAE 189.1 is the standard for design of high performance, green buildings, except for low rise residential buildings. 
• Title 24 includes energy efficiency standards for residential and nonresidential buildings. While Title 24 is officially part of the California Energy Code, note that codes beginning in California typically make their way through the rest of the country and are accepted as best practices before becoming actual codes in each locality. 
• The International Code Council (ICC) has recently created the International Green Construction Code (IgCC), which provides a baseline of energy efficiency from the building design phase through occupancy. 

These codes are associated with modifying building construction and renovation practices to save energy in safe, practical ways.

Energy Savings – #1 Benefit

First and foremost, daylighting saves energy- thus introducing natural light into the building means artificial lighting can be turned off or dimmed. 

This can be done manually (open loop), or there are photocontrols available that use sensors to read the natural light coming in the room and will adjust the artificial lighting automatically (closed loop). In addition, artificial lighting creates heat inside the building. Having the ability to dim or turn off the artificial lights greatly reduces the cooling load. 

According to the USDOE, lighting and HVAC are responsible for most of the energy use in a building. Determining exactly how much energy can be saved depends upon the energy efficiency (U factor) of the skylights or sidelights, as well as the type of artificial lighting being dimmed or switched off. 

To determine the exact calculations, there are some websites that can help; one option is the United States Department of Energy (USDOE) website at www.eere.energy.gov. You can also visit the Metal Building Manufacturers Association (MBMA) website at www.mbma.com to learn further information on sustainability or to obtain their Energy Design Guide for Metal Building Systems manual. For more info on how Palram products contribute to energy reduction & earning LEED® credits, see Palram’s Products for Sustainable Building Outline. 

The ‘Human’ Benefits of Daylighting 

Natural daylight can create positive changes in people. The electromagnetic spectrum of radiation transmitted from the sun is called the solar spectrum, and is made of UV light, visible light, and infrared light. The visible light spectrum is essential for proper visual performance, and to reduce the effect of metamerism, specifically illuminant metameric failure, where colors will appear differently in different sources of light. Put more simply, natural light is the best source for color comparisons. Artificial lighting lacks most of the blues in the spectrum, causing eye strain and poor visual performance.

Humans operate under a circadian rhythm, meaning we have an ‘inner clock’. The introduction of daylight is one of the most important factors in keeping this process in line. When the circadian rhythm is upset due to lack of daylight, this can cause many problems, including hormonal imbalances, sleep disorders, and mood disturbances. 

Daylight is also beneficial in preventing such afflictions as Seasonal Affective Disorder (SAD) and even Sick Building Syndrome (SBS). As data shows, happy humans are more productive. Daylight helps people feel better, motivating them to do more. 

Daylighting Integration 

Now that we’ve covered the benefits of daylighting, you may be asking yourself how you can implement it for your next project.

Skylights can be installed in different configurations: (see graphic below):

• Checkerboard style
• Ridge-to-eave
• Mid-span
• Continuous or horizontal 
• Saw tooth/north lights 
• Side lighting (vertical or horizontal) 

When determining where to place sidelights, a north or south facing wall is best for more even lighting throughout the day. East and west facing sidelights often have harsh glares and provide light for only short portions of the day. For additional or total light diffusion, optional pigments can be added to the glazing to diffuse the natural light, reducing glares and hotspots, and helping to spread the light throughout the structure or space. 

Installation

Installing polycarbonate skylights and sidelights is relatively easy. The corrugated panel installation is virtually the same as any corrugated metal roofing or wall panel, with the exception of pre-drilling holes and the type of fastener used for proper installation. 

The pre-drilling is necessary to allow for expansion and contraction, as polycarbonate expands and contracts at a different rate than metal. Rubber butyl tape or a compatible silicone caulk, along with positive drainage, should alleviate any leakage concerns with skylights. Leaks typically aren’t a concern for sidelights.

Multiwall skylight or sidelight installation is essentially as easy as corrugated. However, there are a few additional accessories used: 

1. A snap HCX channel which is used to join 2 panels together in the longitudinal direction
2. Breather tape for the top and bottom ends of the panel to keep out dirt and debris
3. U channels which hide the unfinished sides and ends of the panels. (As is the case with the corrugated skylights, all fastener holes must be pre-drilled to allow for thermal expansion of the material.)

Be sure to read the entire installation guide for any chosen skylight or sidelight system to ensure proper panel performance.

Life Expectancies & Warranties 

Most polycarbonate manufacturers offer some type of warranty against discoloration and impact resistance against hail for up to ten years, although many polycarbonate installations have been in place for 20 years or more. 

Polycarbonate has better impact resistance than many other materials available on the market. Commercial warranties may vary considering the product might be installed in an area where it may be subjected to chemical attack, such as a waste treatment facility or harsh cleaning compounds. 

It is important to note that UV inhibitors increase the life expectancy of polycarbonate panels. A co-extruded UV layer creates a more permanent bond and will not delaminate or crack. 

Recycling 

In addition to a potentially 20+ year lifecycle, once the polycarbonate panels need to be replaced, they are 100% recyclable, which reduces waste in landfills. 

Conclusions about Natural Daylighting

Superior to artificial lighting, daylighting not only saves energy, but also elevates human moods, and can even enhance performance. So, while the electric bill gets lower and lower, shoppers are buying more in retail facilities, children are doing better on tests in schools, factory workers are more productive, and the cooling load in the building is dramatically reduced. Polycarbonate skylights and sidelights are among the most durable options available and allow for full spectrum lighting to be introduced into the building to produce those positive effects, plus offer the opportunity for LEED® credits. 

As energy codes become more stringent, natural daylighting is going to become even more important for both new construction and renovations. Implementing daylighting in your current projects will put you ahead of the competition while future-proofing for the coming years. 

About Palram Americas

Palram Americas is an end-to-end, state-of-the-art thermoplastics manufacturer based in the Lehigh Valley, PA. For 60 years, Palram has provided high-quality polycarbonate & PVC solutions used in countless markets spanning construction and architecture, sign and display, agriculture, safety & security, transportation, DIY and outdoor living.

Whether you’re a contractor, fabricator, designer, architect, printer, or even a homeowner interested in DIY projects, Palram’s range of polycarbonate and PVC solutions will help transform your vision into reality. Together, we will build on.

To learn about Palram’s architectural skylight/sidelight solutions and MetalMatch technology, see here. 

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