NIR Green

 
What are Cool Roofs?

 
Cool Roofs use roofing materials that are highly reflective (also called high albedo roofs) of the sun’s radiant heat. They may also have a high thermal emittance value. Emittance is a measure of how much of the absorbed radiant energy is given off into the atmosphere - keeping the surface cooler as a result. One of the issues given enormous attention in the last few years is the usage of Cool Roofs to mitigate the Urban Heat Island effect. The Urban Heat Island effect is the creation of higher ambient temperatures in densely compacted urban areas than the surrounding suburban areas. It is a result from reduced vegetative growth as well as a higher incidence rate of black or dark colored pavement and roofing. Typically, Cool Roofs are those with a solar reflectance value of 0.65 or higher when new. That means 65% of the total radiant heat energy is reflected back into the atmosphere.
 
Fact: As much as 40% of a city’s impervious area is composed of roof area.
 
Why is an Urban Heat Island significant?
Because it means that more cooling energy is needed for occupied spaces in these urban areas. There is also a higher incidence rate of air pollution created that includes the production of ozone.
 
Cool Roof Studies
Studies have shown that if cities were to install only Cool Roofs, significant energy savings will result as well as an improvement in urban air quality. These studies have led to local and state-mandated commercial roof regulations. They are rapidly proliferating to other locales that see cool roofing as an inexpensive means to reduce overall energy consumption. Such programs as Title 24 in California and regulations in the State of Georgia, Salt Lake City, Chicago and other urban northeastern cities are examples of trends being adopted nationwide.
 
What is Daylighting?

 
As the name implies, daylighting is a strategy for reducing energy use by using natural daylight for illumination in occupied buildings that allows reduction of the amount of electric lighting needed. Calculations for the amount of lumens needed in a space for different tasks are often performed to optimize the lighting required. The amount of illumination provided by natural daylighting is calculated under varying conditions including overcast conditions so that a range of illuminances are determined and used to supplement the required electrical lighting load. Location of openings becomes a key factor as well. Studies have shown that glazing located high in a wall allows daylighting to penetrate greater distances into a room. Additionally, as the height of the windowsill increases, the point of maximum illumination moves away from the window.
 
Natural Daylighting
In using natural daylighting as a primary source of lighting in commercial buildings, the concern becomes how to get natural daylight into spaces that are furthest away from daylight sources such as windows. Skylights are used as one method to allow daylighting to illuminate interior spaces. The general rule of thumb is to space skylights one to 1.5 times the height of the room. The most illumination is obtained when a series of smaller skylights are inserted in ceilings of rooms and have been shown to be the most energy efficient pattern of adding daylighting into interior spaces. Additionally, the use of reflective light shelves at windows can also be used to allow daylighting to be reflected further into interior spaces as well. The introduction of highly reflective tubular skylights called Solatubes or Apollo Light Pipes allow daylight to be collected and introduced into spaces in which more conventional skylights cannot be constructed.
 
Fact: One study by Southern California Edison in retail spaces showed a 26% improvement in sales volume in large retail stores that had skylighting versus similar stores without skylights. Other studies have shown that retail stores that have no skylights can expect approximately 40% higher sales volume merely by installing skylights in their retail facilities.
 
Daylighting Interior Spaces
The addition of natural daylighting into interior spaces have been shown in many studies to have tangible productivity benefits. Some of these benefits include reduction in employee absenteeism, higher retail sales, and improved student health and academic performance. The Heschong Mahone study found that students in spaces with the most daylighting in their classrooms progressed 20% faster on mathematics tests and 26% faster on their reading examinations versus those students in classrooms with the least amount of daylighting.
 
What are Garden Roofs?
One of the most interesting roof types being proposed and installed as a solution to mitigating the Urban Heat Island phenomenon is the Garden Roof, a better descriptor than the broader term Green Roof that can refer to reflective cool roofs as well. Essentially, the low-slope roof area is covered with a roofing membrane but installed on top of that roof membrane is a series of planting containers that are filled with growing medium and plants.
 
Types of Garden Roofs
Intensive - are planned and designed roofs incorporating planting media up to several feet in depth requiring extensive maintenance. These roofs are intended for public access and use; usually built-in-place.
Extensive - have planting media eight inches or less in depth with few maintenance requirements and are not intended for public access; usually composed of recycled plastic modular planting units.
 
Benefits of Garden Roofs
- Mitigate Urban Heat Island effect
- saves energy, reduces rooftop temperatures
- Manages storm water runoff
- Aesthetic improvement-adds value
- Reduces glare to surrounding buildings
- Increases oxygen production
- Plants absorb CO2
- Absorbs sound - due to increased mass
- Reduced HVAC requirements
What is the LEED program?
LEED is an acronym for Leadership in Energy and Environmental Design.
 
Who administers the LEED program?
LEED is a program sponsored and administered by the USGreenBuilding Council.
 
What is LEED’s purpose?
LEED’s purpose is to provide a rating system that incentivizes designers and builder’s decisions to choose “green” building products for the construction and operation of buildings.
 
How is a LEED credit obtained?
LEED provides a set of widely accepted criteria as guidelines for choosing “green” products. Selecting “green” products over more traditional ones can provide LEED credits.
 
What is a “green” product?
1. Technically, a “green” product is one that has minimal impact to the environment.
2. Green products are factors in designing for sustainable development.
 
What is meant by sustainable development?
Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
 
Are building products the only way to obtain LEED credits?
No. How and where the site is selected and used as well as how the building affects the surrounding microclimate’s environmental conditions make up some available LEED credits.
 
Does NIR use products that can lead to a LEED credit?
Yes, reflective roof membranes and coatings qualify for a LEED credit. Depending on recycled content, some products may qualify for an additional LEED credits. (wood fiberboard, iso, EPS). Amounts of insulation above that required by code can be seen as an additional LEED credit. Depending on job location, products used from manufacturing locations within 500 miles of the job may also be considered for a LEED credit.
 
What is a LEED certified project?
A LEED certified project is one that has submitted documentation to the LEED Steering Committee for verification of the total number of credits allowed by LEED guidelines for certification. A minimum of 26 LEED verified credits is required to be awarded “certification” status for New Construction and 39 LEED credits for Existing Buildings.
 
PhotoVoltaic Solar Systems

 
PhotoVoltaic (PV) Solar Panels are designed to produce electricity from exposure to the sun’s radiant energy. This electricity is considered “free” electricity since no fuels are used to produce it. The mechanism is fairly simple. Silicon wafer semiconductors are exposed to the radiant energy of the sun and produce a small electrical current. To make enough power to matter, groups of these semiconductors are connected together in a panel. These panels are arranged in arrays so that the wattage produced is then transferred to a power inverter that converts the direct current produced by the panels into more usable alternating current to run appliances, etc. Until recently, these PV panels were composed of large, bulky, glass-enclosed panels that created holes in the roof where they were mounted, requiring a host of flashing details that the PV installer was ill-equipped to address. The new generation of PV panels are laminated to flexible panels of polymeric membrane at a much reduced cost and reduce the number of roof penetrations since they need no special mounting racks that penetrate the roof. Instead, the flexible laminated PV film panels are hot-air welded directly to a compatible roofing membrane conforming to the roof membrane’s contours.
 
Benefits of Film-laminated PV Panels
 • Minimizes roof penetrations for installation
 • Effective without having to be angled directly to the sun
 • Increased security and wind resistance due to fusing films directly to the roof membrane through hot air welding
 • Lighter weight than glass panels adding very little additional load to the structure
 • Lower cost to manufacturer
 • Higher electrical conversion efficiency
 
This technology is also available in the form of smaller roof tiles that can be used in residential applications, taking the place of conventional roof tiles or shingles.
 
Fact: Federal Tax incentive: 30% Investment tax credit on installed system cost. Other regional power companies may offer rebates for PV systems as well.
 
To see specific state incentives, use the following website: http://www.dsireusa.org

 

 
About Roofing Products Recycling
The practice of recycling is somewhat obvious from its name. Generally, recycling is: - Re-using a material after its initial service life ends by reprocessing into a new product - Re-using edge trim during manufacture and adding to virgin material. This re- use of edge trim and other scrap during manufacture results in the reduction of virgin materials use and the reuse of waste materials instead of going to and fills. Common organic roofing materials that can be easily recycled are wood fiberboard insulation and perlite insulation. The Biggest downside to recycling is the economics - it can be costly and there are no centralized recycling centers.

Characteristics of Recyclable Materials

- Ability to be easily re-introduced and processed into a new product
- Easily separated from other additives and ingredients
- Easier to accomplish with thermoplastic materials or organic materials
 
Why?
Because thermoplastic materials are not molecularly cross-linked allowing them to be reformed with the introduction of heat and pressure. Thermoset materials, by contrast, cannot be easily re-used once their molecules have cross-linked. That means that thermoset materials must be ground up into small particles and dispersed in a polymeric matrix to be recycled.
 
What is a Thermoplastic Material?
It is a material that does not undergo a molecular cross-linking and remains in a state that allows it to be fused and formed into alternative shapes and forms through the application of heat and pressure.
 
Examples of common thermoplastic roofing materials are:
- TPO n PVC n EPS
- XPS n Uncured EPDM n Asphalt
 
Thermoset materials go through a process that results in cross-linking of molecules (also called “curing” or “vulcanization”) that permanently sets the physical properties in the material. Examples of common thermoset roofing materials include EPDM and polyisocyanurate insulation.
 
About Green Construction Tax Incentives
There are numerous state government and power company programs, rebates and incentives to make choosing sustainable products and practices fiscally rewarding and to induce designers and building owners to adopt green strategies for their facilities. Some of the most financially rewarding of the state and local power company programs can be found at the website: http://www.dsireusa.org
 
Additional Programs
In addition to the programs that vary from state to state and from power company to power company, there is also a federal tax deduction available through the Internal Revenue Service for commercial property owners. This tax deduction is for commercial property owners who bring their property up to a minimum level of energy efficiency or even greater than the minimum requires and was enacted in the 2005 Energy Policy Act. It is only for buildings that were retrofitted after December 31, 2005 and prior to January 1, 2009. The qualifying building must have reduced energy costs resulting from the building’s heating, cooling, ventilation, hot water and interior lighting by 50% from a reference building meeting the minimum requirements of ASHRAE 90.1-2001 Standard.
 
Deductions
The amount of the deduction is $1.80 per square foot of conditioned area if the 50% improvement is documented. Lesser deductions are available up to $0.60 per square foot if the energy improvements reach a minimum level of 16 2/3% above the reference building mentioned above. The Department of Energy also lists acceptable computer programs that can be used to calculate and verify the energy improvement. These deductions are available for buildings or systems placed in service from January 1, 2006 through December 31, 2013.
 
Title 24
The California Energy Commission (CEC) created regulations to reduce California’s energy consumption and provide Energy Efficiency Standards for Residential and Nonresidential buildings that is formally titled “California Code of Regulations, Title 24, Part 6”. The Cool Roof Update adopted in 2005 further sets cool roof energy standards for design and construction of roofs in California. This new regulation added a prescriptive requirement for non-residential buildings with low slopes.
 
What does Title 24, Part 6 now require?
Prescriptive requirements to install roofing materials that have an initial solar reflectance of 0.70 or greater and an initial thermal emittance of 0.75 or greater. Aged reflectance and emittance values will become the standard for compliance in the future.
 
What buildings are affected?
All Low-Slope (<2:12) non-residential roofs over conditioned spaces (heated or cooled) that are New Construction or are an existing building and is being reroofed that has a reroof area of 2000 s.f. or more or the amount of the area of roof to be reroofed is 50% of the total roof area…then compliance to Cool Roof Prescriptive requirements are mandatory.
Note: The rules are a little different for both high-rise residential buildings and hotels.
 
Are there any exceptions?
Yes. If an existing non-residential building’s roof is a BUR or Modified Bituminous roof with a rock or gravel surface, no removal of existing layers or installation of insulation is contemplated and there is no recoating with liquid applied coatings contemplated, then reflective roofing is not required.
 
How will this be enforced?
Evidence of compliance is determined by providing labels of the CRRC-rated products that are proposed when applying for a building permit. Non-complying roof systems will not be acceptable and do not allow the permits to be issued.
 
What is a CRRC-rated product?
CRRC is the Cool Roof Ratings Council – an independent and unbiased organization that establishes test criteria for compliance to Title 24. CRRC is also a clearing-house for verification and dissemination of this information. Specific labels showing compliance to Title 24 requirements are licensed to the manufacturers’ of materials that have undergone testing to CRRC protocols. These labels show the reflectivity and emissivity values for the tested roof product.
 
Can NIR provide CRRC-rated products?
Yes, we do use various TPO and PVC membranes that are Title 24 compliant materials. In addition, some of the white coatings used over SPF are also Title 24 compliant.
 
Besides CRRC-Rated Roof Products are there also minimum insulation requirements in Title 2?
Yes. Depending on the location of a building in California, minimum U values have also been established for compliance to Title 24.
 

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