Daylighting and Energy Usage

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A good daylighting system is the easiest and most cost-effective way to light a space and reduce energy usage. After all, the sun provides everyone with a lot of free light and energy every day, it makes sense to take advantage of it. However, placing just adding in skylights or windows without thought is a recipe for disaster; or really just some discomfort, but you get the idea.

An average grocery store might save about $16,000 per year in operating costs, or $0.32 per square foot with the use of an appropriately sized skylighting system.

 

Controlled Daylighting

hm-brown-daylighting-energy-usage-3To achieve reduced energy usage and save on operating costs the daylighting must be intentional and controlled. It is equally important to install and implement lighting controls. If the office worker or employee’s turn on the electric lights, there will be no savings.

Why are electric lights so expensive to run? About half of a light bulb’s energy consumption is released as heat, making them fairly inefficient. LED technologies are improving this percentage, but they still cost money.

Potential Energy Savings

A good daylighting solution will reduce overall energy usage of any building. For example, the potential savings for a few typical buildings in the Los Angeles area were calculated*. An average grocery store might save about $16,000 per year in operating costs, or $0.32 per square foot with the use of an appropriately sized skylighting system. A typical elementary school might save about $7,500 per year in operating costs, or $0.23 per square foot. An industrial processing and distribution center might save about $0.12 per square foot.

*Using 1998 energy costs, weather conditions from the San Bernardino Valley, and a few default assumptions.

Daylighting and the Energy Codes

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Better Performance Required

Throughout the US the energy codes are being rewritten. As energy demands increase, The US Dept. of Energy is requiring higher and better performance from buildings. But the interesting thing to note is that the US Dept. of Energy is requiring more daylighting at the same time. This can be a challenge to increase the amount of daylighting while at the same time increasing the energy performance of the building.

energy-codesToday, any new buildings over 10,000 square feet are required to have daylight space.

It is critical that energy codes are followed. Not following the code or ignoring NFRC can result in loss of LEED points.

Translucent Vs. Transparent Daylighting

transparent vs translucent daylighting

When Should You Use Transparent Daylighting and When Should You Use Translucent?

Proper daylighting design requires use of both translucent vs. transparent daylighting. Glass or other transparent glazings provide a view of the outside, making the room feel larger and bringing the outdoors in. However, glass also brings in solar heat and causes glare, making the space uncomfortable and difficult to work in.

Translucent Vs. Transparent Daylighting

Translucent Daylighting Is the Most Cost Effective

Utilizing translucent daylighting is the most efficient and effective way to provide natural daylighting. Translucent panels are far more effective at blocking heat, providing savings in energy usage. Translucent panels also scatter the light, eliminating glare and reducing the amount of both artificial light and amount of daylighting needed, reducing both operating costs and installation costs. Translucent panels are cheaper to manufacture and install than glass, providing the best cost to usage ratio.

CPI Daylighting’s translucent polycarbonate, like their UniQuad or QuadWall products, provide highly diffused light without glare or solar heat gain. Diffuse light is like light on a cloudy day; small shadows, no spotlighting, low heat and easy on the eyes.

Transparent Daylighting Provides a View

Glass on the other hand provides a view. However the tradeoff is that it also delivers glare and solar heat gain. Glass is also expensive, and to get similar U-values, the glass has to be coated, triple pane, and insulated with argon gases, all adding to the costs. The seals will eventually break down, the gases leak out, and performance drops, and either replacements are expensive and difficult, or impossible.

But, there are areas that a view is necessary. No one wants to work in a building without a window or view outside. So the key is to balance the translucent vs. transparent daylighting in the design.

Translucent Vs. Transparent Daylighting Usage

For general use, walls at eye height (6 feet – 8 feet) should have some transparent glazing, allowing for views outside. In almost all other cases translucent daylighting provides the best performance at the best price. It really depends upon the usage: gymnasiums work best with translucent daylighting, and office buildings do well with translucent daylighting, as glare and heat can drop productivity quickly.

Commercial Flat Roof Daylighting Solution

The Velux Commercial Sun Tunnel for a Commercial Flat Roof

Getting cost-effective daylighting into a commercial building can be a challenge, especially when most have a commercial flat roof. Velux Commercial Sun Tunnels are a great potential solution.

Why Velux Sun Tunnels?

The Velux SunCurve diffuser is designed to capture light at all times of the day and reflect it down the shaft, giving you ample daylight dawn dusk.

Velux Sun Tunnels have a variety of parts and accessories to work with whatever needs your location might need; from forced entry protection, A, B, or C fire classifications, to a daylight controller for room darkening.

Sun Tunnel Parts and Accessories.

Velux also provides the best warranty, giving you peace of mind.

Ideal Applications

Velux Commercial Sun Tunnels were created for commercial flat roof applications, no matter the material. They work best over areas that can benefit from natural daylight, and help reduce energy loads and improve the comfort and performance of employees, guests, or customers.

Open Ceiling Sun TunnelSchools, retail spaces, warehouses and office locations benefit the most from Velux Commercial Sun Tunnels. They provide a very cost-effective way to bring in daylight through the roof. Even greater cost savings can be attained with open ceiling applications.