"Economical solutions for drastically reducing energy demand..."

Skylights- F.A.Q.

Frequently Asked Questions:

Q. Is the light from prismatic daylight adequate to replace electric lights?

A. YES. In fact a properly designed daylighted space with Vanguard Prismatic Skylights have been proven to be able to shut off electric lights for an average of 8 hours a day during the highest cost of energy time of the day. Vanguard skylights have the highest level of light transmission with 100% diffusion of any other skylight on the market and can replace electric lighting sources for 70 to 80% of the daylight hours.

Q. Will daylighting work on a cloudy day?

A. There are varying degrees of cloudy days, from thunderstorm skies to overcast mornings. With lighting control solutions that allow for daylight dimming or staging, a properly designed daylighted space can still provide energy savings on overcast days. However, if a dark heavy thunderstorm is overhead, electric lighting will be necessary during normal daylight hours. However, this type of day is the exception and not the norm.

Q. Does daylighting ever cause excess heat or brightness?

Proper daylighting design with Vanguard Energy Solutions does not. In fact, properly diffused daylighting with high transmission values provides twice the lumens of florescent lighting per mmBTU. What this means is, proper daylighting is twice the light or half the heat of florescent lighting. While clear skylights let in direct sunlight, causing
"a wandering hot spot" that cause excessive glare, UV damage and can interfere with electronic equipment, Vanguard Prismatic Skylights utilize the power of prisms (over 4,000 per square foot) that allow for maximum light transmission while still providing 100% diffusion for a glare-free, flicker-free light source.

Q. Can daylighting levels be controlled like electric lighting?

A. Yes. Through the use of lighting control systems and photocells, electric lighting systems can be coordinated to maintain foot-candle levels while maximizing energy savings. In commercial and educational facilities, light control louver systems are available to maintain constant light levels as well as the ability to turn off daylight completely to show video presentations or movies. With simple, cost effective systems, daylighted spaces can be controlled in the same way that electric lighting systems are.

Q. What kind of output will daylighting produce during winter months or low sun angles?

A. Vanguard Prismatic Skylights provide 35% or more light transmission then any competitive skylight while still providing 100%
diffusion. Even during winter months where the sun is lower in the horizon, Vanguard allows a building owner more hours of electrical energy savings by shutting off lights compared to the competition.

Q. Will daylighting with Vanguard create a glare during peak hours of sunshine?

A.  No. Vanguard skylights control light transmission and diffusion through our glazing products. This allows us to maximize the light transmission of our skylights while maintaining 100% diffusion. This allows us to bring in as much of the available daylight as possible and spread it throughout the space without hotspots, glare or UV damage during the peak energy load, peak sunlight time of the day.


Q. Will my heating and/or air conditioning bill go up?

A.  No. We have made insulated thermal breaks standard in all double and triple glazed units to protect against the elements. Conversely, since daylighting is one of the coolest forms of light, it produces much less heat than electric lighting for no heat gain.

Q. Is daylight expensive in install?

A. No. Our standard is exceptional performance without the premium price, and both product cost and installation are quickly offset by your dramatic energy savings. You’ll also enjoy free design assistance.

Q. Will my daylighting products need to be cleaned often to stay at peak effectiveness?

A. Our lenses are unmatched for light transmittance when new, with practically no depreciation of transmittance or yellowing over time.

Q. Standard skylights are notorious leakers and high-end, well-flashed units are expensive. Do the benefits outweigh the extra cost?

There is a misconception in the market that all skylights leak and the cost of skylights that don’t leak outweighs the benefit. However, there are high-performance fixed skylight units on the market that are very cost competitive and pay for themselves many times in less than two years. It comes down to the fact that building designers and specifiers need to do their research into the complete framing and glazing design of the unit they specify. Just as in roofing, details to design and moisture control are not equal in all units. However, it doesn’t mean that a better design has to cost substantially more. Does the unit use multiple seals and if those seals fail, where does the water go? Does the unit have condensation control on the inside of the unit and if interior moisture builds up, where does it go? Does it have insulated thermal breaks or even foam curb seals and sweeps to protect against driving wind and moisture to the unit? Daylighting with skylights is a powerful energy tool and it is a way for a building owner to put their roof to work for them instead of just being a 39-½ year depreciating asset. Don’t count out daylighting based on antiquated glazing designs. Cost effective, high-performance skylights do exist.

Q. What are some of the newest gadgets? We’ve heard of shutters that open and close automatically based on temperature and/or light intensity.

Light control louvers do exist and, with the right control system, can provide a solution that maintains constant lighting foot-candle levels with daylighting as well as the ability to shut off daylight in cases where video presentations are commonplace, such as schools or boardrooms. Another gadget on the market are sun tracking mirror skylights that through the use of GPS, track the migration of the sun and claim to draw more light in during times of the day and months of the year when the sun is lowest in the horizon. These systems are considerably more expensive then fixed units and only come in 4’ x 4’ sizes. Compared to a 4’ fixed unit, they can bring in more light at low angles. However, when compared to a high-performance prismatic skylight, you increase the unit to a 4’ x 6' unit and the fixed prismatic will outperform the tracking skylight at all hours of the day for a mere fraction of the price and with no moving parts to service.

There are many claims in the marketplace and specifiers and architects should be diligent in asking for third party verification on these claims. There is a tremendous amount of testing and research available on the energy efficiency opportunity available with daylighting and research shows that toplighting through skylights is the most effective and efficient way to daylight spaces. Long-term, high-performance skylight systems are available at competitive prices and provide quick payback opportunities through energy efficiency. Many large retailers, distribution companies and commercial office building owners consider high-performance daylighting systems to be part of their competitive advantage as every dollar saved in energy expense is pure after tax profit back to the business. Daylighting spaces properly is a huge advantage for a building owner.

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