How The New VTannual Rating Affects Daylighting

If you’re involved with daylighting commercial buildings, you need to know about optically complex fenestration systems and the new VTannual rating.
   Optically complex fenestration systems are technologically advanced products that use specially engineered light-bending or light-reflecting elements to harvest the wavelengths of light that we want to use to illuminate building interiors. One key example of these new types of optically complex fenestration systems is the tubular daylighting device (TDD), which collects and admits natural light into interiors more effectively than conventional daylighting options.
   Featuring progressive technologies, these optically complex systems use stringent refractive, reflective, and filtering elements to selectively harvest natural light over the course of a year. Compared with traditional skylights, windows, and less-complex TDDs, state-of-the-art TDDs use advanced optics and materials to deliver higher quality visible light with more consistent illuminance, regardless of sky condition or climate. They also significantly reduce the potential for shifting light patterns, glare, and heat transfer issues.

Current rating issues
So how do building designers know which optically complex system offers the best performance for their particular projects? Currently, visible light transmittance (VT) is a factor commonly used by architects, engineers, and contractors to predict a daylighting system’s light output. It’s also a performance rating that is measured using testing and rating protocols established by the National Fenestration Rating Council (NFRC), Greenbelt, MD.
   The issue with the VT rating is that it doesn’t sufficiently account for the light-collection control that can be designed into optically complex fenestration products. These systems are engineered to filter out undesirable wavelengths—such as fabric-fading ultraviolet, heat-carrying infrared, and overpowering midday sunlight—so the collection and transmission of light varies, by design, throughout the day and year. This variance makes product comparisons difficult and the simple VT measurement a poor performance indicator.

Devising a new rating
Measuring simple VT involves direct-normal testing where a single beam of light is aimed into the optically complex system from directly overhead. There are two problems with the test. First, natural light transmits through a surface at a variety of angles throughout the day (depending on the sun’s position in the sky), not just in a perpendicular fashion. Second, this method doesn’t allow the benefits of technology to come into play, such as dome optics or optical tubing reflectance. Every daylighting system performs relatively the same when using this testing protocol, so it does not offer an accurate depiction of a product’s real-life performance. As a result, it doesn’t provide a valuable resource to the consumer when trying to select the best product for a particular application.
   To select the best daylighting system for a given project, commercial building designers must be able to compare product performance with respect to daylighting configuration and geographic location as well as climatic and seasonal variations. Until now, the lack of standard performance metrics that adequately address this new breed of daylighting systems has made the simple comparison and selection of optically complex systems virtually impossible.
   Enter the NFRC Tubular Daylighting Device Task Group. Consisting of members from the NFRC, including technical representatives from the Lawrence Berkeley National Laboratory (Berkeley, CA), testing laboratories, and several major TDD manufacturers, this collaboration has worked for more than four years to develop a new performance testing protocol for collecting and rating visible transmittance data for optically complex systems.
   The outcome of the group’s efforts was a new annualized visual transmittance rating protocol (VTannual), which was implemented by the NFRC in late 2013. The new VTannual protocol offers a more meaningful performance rating that provides an extremely accurate view of how an optically complex system will perform in real-life situations. It will allow building designers to make a true “apples to apples” comparison between daylighting products so they can choose the best system to meet their project goals.

This illustration is a graphical representation of solar angles defined and utilized within the NFRC VTannual rating protocol. Illustration courtesy of NFRC.

This illustration is a graphical representation of solar angles defined and utilized within the NFRC VTannual rating protocol. Illustration courtesy of NFRC.

Calculating VTannual
To calculate the VTannual rating, a specially designed apparatus measures a daylighting product’s:

  • Annual visible transmittance: the annualized amount of daylight transferred through a surface into an interior space.
  • Zonal time (ZT) weighting factors, which are a function that determines the percentage of time the sun spends within a specific patch of sky.

   The apparatus does this by collecting clear-sky, visible-light-transmittance data for a series of vertical planes of data in 10-deg. increments. The measurements span vertical angles for solar altitudes (angles of the sun above the horizon) ranging from 20 to 70 deg. at three specific solar azimuth angles (the compass direction from which the sunlight is coming, i.e., east or west relative to due south) of 0, 30, and 60 deg.

Figure 3 (Figure 2 is not shown) is a depiction of solar altitude angles as measured with respect to the opening of the moveable test apparatus. Illustration courtesy of NFRC.

Figure 3 (Figure 2 is not shown) is a depiction of solar altitude angles as measured with respect to the opening of the moveable test apparatus. Illustration courtesy of NFRC.

   Ultimately, 18 distinct points of paired data are collected, then factored in with the historical position of the sun for a preselected site location which, for the NFRC rating, will be a standard Middle America location at 40 deg. north latitude, i.e., Boulder, CO. These can then be used to generate functional, annualized, visible-light-transmittance ratings for any site location in the world, accounting for how an optically complex product is designed to selectively increase or reduce light collection for specific times of the day and year.
   It’s important to note that the VTannual rating is based on clear-sky conditions only. Thus, the new rating will be less useful for people who live in predominantly overcast or cloudy climates.

Obtaining a rating
To obtain a VTannual rating, a manufacturer works with a third party testing organization to conduct the test. The results are then sent to an independent inspection agency to review and verify the test data and rating results. If the data are deemed to be accurate and conform with the testing standard, an NFRC label with the rating is issued to the manufacturer for use on its packaging. The data are also uploaded to the NFRC Certified Product Database.
   The VTannual rating is designated as a single number that represents the annual average clear-sky visible transmittance of a daylighting product for a standard Middle America location. This accounts for the actual time-weighted path the sun travels during the course of the year, and is expressed as a number between 0 and 1. This differs from the static direct-normal VT rating, also expressed as a number between 0 and 1, which, for a skylight, represents the ideal maximum light transmittance of a product when the sun is directly overhead, a condition that never happens for all but a few hours each year for sites within the tropics near the equator.

Taking a new approach
Optically complex systems are forcing a paradigm shift in commercial-building design. With their ability to collect, filter, and redirect daylight, they have made it easier for natural light to become the primary daytime illumination source, with electric lighting taking a supplementary role. These systems are not your average TDDs, but fully vetted lighting equipment that has been proven to perform.
   The adoption of the VTannual rating protocol is a crucial part of this new approach to commercial lighting. It is a significant advancement in how fenestration products are evaluated because it allows those involved with building design to make educated decisions based on a product’s real-life performance, and eventually the data collected in the NFRC VTannual rating process may even allow annual performance values to be calculated relative to the building’s actual geographic location.
   Architects can now make direct comparisons, which allows them to specify and select the best product for the application. They can even calculate how much useful light is available, making it possible to estimate how much electric light is needed to make up for any deficiencies during any hour of the year. Look for the new performance rating on NFRC labels starting in the Fall of 2014.

Neall Digert, Ph.D., MIES, is vice president of product enterprise, Solatube International Inc., Vista, CA.

Precast concrete rings create artificial reef structures

image002Wayfarer Environmental Technologies’ OysterBreak artificial reef structures use strategically placed submerged precast concrete rings which employ the oyster’s inherent nature of clustering to fill in the gaps, creating an artificial reef. The system uses stacks of specially designed concrete rings similar in size, shape, and weight to spacer rings used on manhole risers, but featuring anchor lugs and wave openings. Each ring is wet cast using an OysterKrete mix design. OysterKrete, invented by Tyler Ortego is a harsh mixture that results in a hardened concrete that resembles pervious concrete.

These living barriers become structures for shoreline erosion protection. Placed in rows two to three deep, the OysterKrete structure allows tidal water to easily move within the structure, while resisting wave action that causes shoreline erosion. In addition, the oysters ‘breathe’ the sediment and nutrients from the water, enhancing the water quality.

OysterBreak is a proprietary precast concrete system that provides shoreline erosion control using artificial oyster reefs. ORA Technologies, is the inventor of a method of shoreline control which creates semi-artificial reefs using oysters. Ortego has licensed his two inventions to Wayfarer Environmental Technologies, of Hunt Valley, Md. In turn, Wayfarer is using Oldcastle Precast as its exclusive manufacturer.

Ten mold inspection steps before buying a commercial building

Mold consultant Phillip Fry has published a list of ten mold inspection steps that need to be taken to protect a real estate buyer:

  1. A careful physical, visual inspection of the roof, attic, all interior rooms, garage, basement, crawl space, and the heating/cooling system to find evidence of building defects, maintenance problems, water intrusion, water damage, and mold growth. Such a thorough inspection will take at least one to two hours or more to be thorough and complete.
  2. During the physical inspection, the mold inspector or environmental hygienist should use a professional moisture meter to scan the entire surface of basement walls and the walls and floors of rooms containing plumbing such as the kitchen, bathrooms, and laundry room.
  3. All furniture and appliances should be inspected for water damage and mold growth on all surfaces, including the backside and bottom.
  4. All drapery, rugs, and carpeting need to be carefully inspected for water damage and mold growth. The inspector should do at least one carpeting mold test to submit for mold lab analysis.
  5. The relative humidity of each room and area of the house (including the attic, basement, crawl space, and garage) should be checked with a hygrometer and recorded in the inspector’s notes. If the relative humidity in a room or area exceeds 70% some or all of the time, such high humidity alone is sufficient to drive big-time mold growth.
  6. The insides of each heating, ventilating, and air conditioning (HVAC) air supply duct should be carefully inspected for accumulated dirt and mold growth.
  7. The outward air flow from at least one HVAC air supply should be mold tested (while the system is running on fan ventilation) for five minutes with an air pump and Air-O-Cell or other appropriate testing media, with a pump air flow rate of 15 cubic liters per minute, for a total air sampling of 75 cubic liters (5 minutes multiplied by 15 cubic liters per minute). This HVAC air sample will then be sent to an accredited mold lab for mold species identification and quantification. If a residence or building has more than one HVAC system, test at least one air supply duct register in each separate system. If a building has a serious mold problem, there is often the presence of elevated levels of airborne mold spores in the HVAC system, which often itself is a location and source for toxic mold growth.
  8. The room air in each of at least three important rooms (such as living room and bedrooms) should be mold tested in the same way previously explained for testing HVAC outward air flow.
  9. If there is any visible mold growth, an actual physical (“bulk”) sample of that mold growth should be collected for mold lab analysis or mold growth colonies should be taken from the moldy areas with such techniques as Scotch tape lift sampling, sterile swabs, and microscopic slide surface sampling.
  10. Surface sampling mold tests should be done to collect landed/deposited mold spores for lab analysis from out of the way places such as the top side of ceiling fans, top side of kitchen cabinets, and the top side of door and window trim that are rarely cleaned. Surface sampling often gives a more realistic insight into the degree of mold infestation than air sampling. The inspector should do both surface sampling and air testing for comprehensive mold testing.

According to Fry, following these steps should help you avoid buying a commercial building that has significant, hidden toxic mold growth inside walls, ceilings, floors, attic, basement, crawl space, and heating/cooling equipment and ducts.

ABI surges, design firms cite increased productivity

AIAShowing a steady increase in the demand for design services, the Architecture Billings Index (ABI) continues to accelerate, as it reached its second highest level of the year.  As a leading economic indicator of construction activity, the ABI reflects the approximate nine to twelve month lead time between architecture billings and construction spending.  The American Institute of Architects (AIA) reported the September ABI score was 54.3, up from a mark of 53.8 in August.  This score reflects an increase in design services (any score above 50 indicates an increase in billings).  The new projects inquiry index was 58.6, down from the reading of 63.0 the previous month.

“The prolonged economic downturn that has affected the design and construction industry has actually resulted in the increased productivity levels as reported by architecture firms,” said AIA Chief Economist Kermit Baker, Hon. AIA, PhD.  “ In addition to new approaches to business challenges, a very competitive marketplace, the utilization of new technologies, and a renewed focus on efficiency have architecture firms realizing all-time highs in workplace productivity, and these new efficiencies can greatly benefit clients from a project timeline and budget standpoint.”

Key September ABI highlights:

  • Regional averages: West (60.6), South (54.1), Midwest (51.0), Northeast (50.7)
  • Sector index breakdown: commercial / industrial (57.9), multi-family residential (55.6), mixed practice (55.4), institutional (50.4)
  •  Project inquiries index: 58.6

The regional and sector categories are calculated as a 3-month moving average, whereas the index and inquiries are monthly numbers.

Geothermal and HVAC textbook now available

Modern Geothermal HVACMcGraw Hill Education has published a follow-on graduate level textbook to its highly successful Geothermal HVAC: Green Heating and Cooling undergraduate textbook, published in 2011. In addition to geothermal consultant Jay Egg, one of the authors to the first textbook, the new volume, Modern Geothermal HVAC: Engineering and Control Applications, which came out this summer, features contributions from Greg Cunniff, P.E., Applications Engineering Manager for Taco, Inc. and Carl Orio, chairman of Water Energy Distributors.

Modern Geothermal HVAC: Engineering and Controls Applications was designed for graduate level students and industry professionals who wish to deepen their knowledge of geothermal applications and advanced hydronics. The textbook contains fifteen chapters ranging in topics from geothermal open and closed loops and standing well methods and applications to HVAC basics, equipment, and the latest developments in radiant cooling with chilled beams, variable speed pumping and controls.

The book also includes the latest information on geothermal rebates, incentives and renewables legislation in place.  Each chapter concludes with a series of review questions.

Modern Geothermal HVAC: Engineering and Controls can be purchased on Amazon. It is also available as an e-book. The book has received wide acclaim from professional engineers, designers, contractors and manufacturers across the industry based on reviews posted on Amazon.

Natural Disasters Top Concern in Recent Safety Survey

According to Staples second annual workplace safety survey, natural disasters are the top safety concern among office employees. Even so, the majority of businesses (60 percent) said recent disasters, including Hurricane Sandy, haven’t led them to reassess their safety plans.

The survey discovered significant discrepancies between safety perception and actual preparedness. Only half of employees said their company communicates a safety plan – a basic tenet of safety preparation – but, three out of four believe their businesses take safety seriously. In emergency situations, nearly 25 percent of employees report their companies only communicate what to expect “at the last minute.”

Furthermore, according to survey results, small businesses appear to be more at risk for safety concerns than medium-sized businesses. Specifically:

  • Less than half of small businesses said they are prepared for severe emergencies or that safety plans are communicated regularly.
  • Thirty-eight percent said their small business does not have safety training or drills.
  • Medium-sized businesses were more likely to have plans in place for emergencies such as evacuation (90 percent), shelter in place (46 percent) and building lockdown (56 percent).
  • Medium-sized businesses reported a wider array of safety equipment on-site.

Safety and Emergency Preparation Tips
Here are some recommendations to help your company prepare for emergencies and maintain a safe work environment:

  • Stock up on emergency items: In addition to an emergency evacuation plan, business should have enough food, water, flashlights and blankets to help sustain employees for up to three days. Items like masks and crank-powered radios can further help businesses be ready for any emergency.
  • Help prevent accidents: The second foremost safety concern among survey respondents was trips, slips and falls. Prevent accidents by installing floor matting and placing hazard signs where appropriate.
  • Be mindful of ergonomics: One-third of respondents experience pain or discomfort at their workstation and a quarter reported “numbness” or “tingling.” Providing ergonomic equipment helps prevent workplace injuries.
  • Back up data: One quarter of respondents do not have access to a secure server for data back-up. To help protect data and make it accessible, consider using a secure VPN, cloud storage and external hard drives.

About the Survey
Staples conducted an online survey of more than 400 office workers and 400 decision makers at organizations of all sizes across the U.S. The survey, conducted in May 2013, asked a series of questions about general office safety.

Bertoia’s Sculptures and Artwork at DORMA Americas Design Center, NYC, May 14-24

DORMABertoia Unbound: An Exhibition of Harry Bertoia’s Sculptures and Artworks will take place May 14-24 at the DORMA Americas Design Center, 1040 Avenue of the Americas, 22nd Floor, in New York City. The Center, in collaboration with Arenson Office Furnishings, will present a display of Mr. Bertoia’s most compelling works, including some of his brilliant sound art pieces.

From the beginning of his career in 1940 until its culmination in the late 1970s, Mr. Bertoia was, fundamentally, a sculptor. He was many other things, too—furniture designer, painter, jeweler—but all are based in his ability to think and visualize in three dimensions. The collection assembled for Bertoia Unbound presents the work of this seminal 20th century figure in all its extraordinary variety and originality.

Attendance at the show is free, by appointment only. Contact the center at 646-574-7464 or

Schools report health and productivity benefits from green school efforts

McGraw-Hill ConstructionAccording to a new report by McGraw-Hill Construction entitled New & Retrofit Green Schools-The Cost Benefits and Influence of a Green School on its Occupants, both K-12 and universities are reporting significant benefits from their green school efforts—both in improved child health, wellbeing and performance, but also teacher and faculty satisfaction. These results are accompanied by reported financial benefits from green school activities.

According to the study, nearly all K–12 school (91%) and university (89%) respondents report that green schools have improved the health and well-being of their students. Additionally, 70% of K –12 schools and 63% of university leaders report green efforts as raising test scores of their students.

Leaders also report other benefits from their green schools efforts:

  • 83% of K-12 and 85% of university leaders report increased faculty satisfaction as a result of teaching in a green school.
  • Nearly a third (32%) of K -12 school leaders report reduced student absenteeism.
  • 48% of K-12 and 56% of university leaders who increased access to natural light and views into their classrooms reported increased student engagement.
  • 44% of K-12 and 51% of university leaders who included improved acoustics in their green projects noticed improvement in student attentiveness as a result of those improvements.

McGraw-Hill Construction’s Dodge Green Construction Outlook, drawn from proprietary project data reported in November that 54% of education construction was green in 2012—up from 30% in 2008, and it is expected to grow, which reinforces the importance of this study and the benefits green buildings can offer.

The report also includes opinions from the design and construction community, and reports form their clients mirror the results from the schools and universities directly. 85% of architects report a positive impact on health and well-being from their green school projects, and 85% of them are reflecting student mobility and health concerns into the design of their buildings.

The study was produced with the support of the U.S. Green Building Council Center for Green Schools, Lutron, Project Frog and Siemens. Survey and data partners included the Council of Educational Facility Planners International, The American Institute of Architects, Associated General Contractors of America, Green Schools National Network, National Association of Independent Schools, National Building Museum, Society for Colleges and University Planning, and Second Nature.

Download the full New and Retrofit Green Schools SmartMarket Report.

Learn LED Basics

LED LIghtingLED Lighting: A Primer to Lighting the Future by Sal Cangeloso. Maker Press/O’Reilly Media, Sebastopol, CA. 59 pages. ISBN 978-1-449-33476-5.

Light-emitting diode (LED) lighting has become all the rage. While the technology is still more expensive than incandescent or fluorescent lighting, there are many applications where the benefits outweigh the cost.

What are those applications? Well, that’s the question this book will help you answer. Not only does it explain LED technology in a straightforward way, it offers some help in making a decision on whether or not to go with LED lighting.

This help comes in Chapter 8, “Do LEDs Make Sense Today?” As the book explains, there are three things to consider when contemplating the switch to LED lighting:

  • initial cost,
  • power savings, and
  • replacement costs.

By replacement costs, the author means not the cost of a replacement bulb, but the labor cost involved in replacing it. For example, if a bulb is located in an inaccessible place such as a fixture high up on a wall or ceiling, the labor cost could be considerable. Using LED lighting reduces these costs because you have to replace them very infrequently.

According to the author, the future is bright (pun intended) for LED lighting. As companies develop the technology, costs will come down, making them the right choice for more lighting applications. “It’s just a matter of time,” he says, “until the light-emitting diode is the tool by which we illuminate the world around us.”

Outlook for construction improve for 2013

Associated General Contractors of AmericaSignificantly more construction firms are planning to add new staff than plan to cut staff while demand for many types of private sector construction projects should increase this year according to survey results released recently by the Associated General Contractors of America and Computer Guidance Corporation. The survey, conducted as part of Tentative Signs of a Recovery: The 2013 Construction Industry Hiring and Business Outlook, provides a generally optimistic outlook for the year even as firms worry about rising costs and declining public sector demand for construction.

Stephen E. Sandherr, the association’s chief executive officer noted that significantly more firms are planning to add staff this year compared to the number of firms expecting to make layoffs. He said that 31 percent of firms plan to add staff this year, while only 9 percent plan to make layoffs this year. The scope of those staff additions are likely to be modest, however, with 79 percent of firms reporting they plan to hire 15 or fewer people in 2013 and only 13 percent planning to hire more than 25 new workers this year.

Among the 30 states with large enough survey sample sizes, 56 percent of firms in Maryland plan to hire new staff this year, more than in any other state. Only 14 percent of firms in South Carolina plan to add staff this year, the least amount in any state. Meanwhile, 37 percent of firms in Michigan plan layoffs for this year, the highest percentage of any state. No firms working in Maryland reported plans to make layoffs this year. (Click here for state-by-state survey results.)

Contractors appear increasingly optimistic that demand for certain private sector projects will expand this year, Sandherr noted. Firms are most optimistic about the outlook for hospital and higher education construction, he said, noting that 36 percent of firms predict the amount of money spent on those projects will grow in 2013 while 39 percent of firms expect the market will remain stable compared to last year. Contractors were also optimistic about the markets for power construction, but had lower expectations for manufacturing; private office and retail, warehouse and lodging construction.

Meanwhile, contractors expect demand for many types of public construction will decline in 2013. For example, 40 percent of contractors report they expect demand for public buildings to shrink in 2013 while only 18 percent expect that market to grow. Another 37 percent of contractors report they expect demand for K-12 school construction to shrink while only 20 percent expect it to increase. And 35 percent of contractors expect the market for manufacturing facilities to shrink this year, while only 23 percent predict it will expand.

A significant – but smaller than last year – number of contractors report that customers’ projects have been delayed or cancelled because of tight credit conditions. Forty percent of responding firms report that tighter lending conditions have forced their customers to delay or cancel construction projects. Only 3 percent of firms reported having an easier time getting credit while 41 percent report no change in credit conditions.

Overall demand for new construction equipment is likely to remain modest in 2013. Sixty-four percent of firms plan to purchase new equipment this year, down from 70 percent last year, while 77 percent of firms plan to lease this year compared to 78 percent in 2012. Contractors are increasingly relying on leasing equipment to avoid having to pay for idle equipment during lags in construction activity, the economist noted. Even as they shift toward more leasing, firms’ appetite for new equipment remains modest, with two-thirds of the firms planning to buy and 73 percent planning to lease $250,000 or less in equipment this year.

Contractors also report being squeezed by rising costs for health insurance and construction materials. Seventy-five percent of firms reported paying more for health care coverage in 2012 and 77 percent expect to pay even more in 2013. Meanwhile, 88 percent of firms reported paying more for construction materials last year while 90 percent expect to pay more for their supplies this year. However, contractors are increasingly optimistic about their ability to raise bid levels. Twenty-eight percent of firms expect to increase the amount they charge for construction this year, nearly double the 15 percent of firms that increased prices in 2012.

An increasing number of construction firms – 38 percent in 2012 compared to 35 percent in 2011 – report using Building Information Modeling services, also known as BIM, association officials noted. And 43 percent report they expect the use of BIM to increase in 2013. In addition, more firms report working on public private partnerships, which leverage private-sector dollars to finance public projects. Thirty-seven percent of firms report being involved in these kinds of projects in 2012 and 97 percent expect demand for these kinds of privately financed projects to increase or remain stable in 2013.

60 percent of firms report they plan to invest in their information technology departments in 2013. He added that 73 percent of those firms report they expect to invest over $10,000 in new information technology this year. However, a relatively small percentage of firms – 11 percent – report they plan to purchase new financial and job cost software in 2013, Kirk added. Similarly, only 9 percent of firms plan to lease or finance the purchase of new financial and job cost software in 2013.

The outlook, which the association co-sponsored with Computer Guidance, was based on survey results from over 1,300 construction firms from 49 states, the District of Columbia and Puerto Rico. Contractors from every segment of the industry answered over 30 questions about their hiring, equipment purchasing and business plans. Economists and specialists from the association and Computer Guidance analyzed those comments to craft the outlook. View Tentative Signs of a Recovery: The 2013 Construction Hiring and Business Outlook Report. View the survey results.