Energy savings analysis has been around for years. There are any number of Internet-based calculators, formulas and procedures for estimating the savings associated with products or actions undertaken to reduce or avoid energy usage. Energy savings is but one component of a much more comprehensive analytical process referred to as life cycle analysis or LCA. But LCA is not nearly so well-defined. Unlike energy savings analysis, which considers a limited number of variables that can be reasonably well defined and quantified, there is no uniform procedure for LCA.

There are some Internet-based calculators for LCA, but they range from being over-simplified to exceedingly complex; from being biased toward individual products or special interests to being overly generic and meaningless. Some approaches to LCA only consider short term direct financial burdens while others consider more indirect or subjective costs both upstream and downstream in the life of a product.

A mainly financial LCA approach for comparing roof systems might consider the following:

• Installation – product cost, installation costs, tear-off costs, disposal costs, business disruption costs.
• Long Term Durability – routine maintenance costs, roof replacement costs.
• Repairs – roof repair costs, interior damage repair costs.
• Energy Savings – estimated savings, rebates and incentives.
• Warranty – cost premiums.

On the other hand, a highly comprehensive environmental-based approach might entail the evaluation of all material and energy inputs and outputs at every stage, from the creation of natural resources through extraction, manufacture, use, and demolition, and disposal of a product. Consider the complexity of the following extreme LCA flow example:

BANG → Earth Appears → Life Begins → Dinosaurs/Other Creatures Appear → Creatures Die/Turn Into Fossil Fuels → Human Race Appears/Evolves → Resources Extracted (fossil fuels, salt, etc.) → Resources Transported to be Processed/Refined → Process/Refine Raw Materials → Process Components (film, scrim) → Produce Product Components (membrane, rigid parts, etc.) → Transport for Fabrication → Fabricate and Assemble The Duro-Last® Cool Zone® Roofing System → Deliver to Jobsite → Installation → Roof In Action (energy savings/heat island mitigation/global warming or cooling or both) → End of Useful Life → Removal/Disposal → Recycle and/or Transport to Landfill → 100,000 to 1 Million Years of Decay and Revert to Fossil Fuels, Salt, etc. → Another BANG!? Or Re-Extraction?

Although this second example seems extreme or absurd, it makes the point that there can be limitless considerations in a comprehensive LCA. The difficulty comes in deciding how far to go and making fair and objective assumptions of all criteria at each stage in the life of the product or system. One of the best things LCA helps accomplish is identification of opportunities for improvement. The important thing to remember in addressing this continuous improvement process is to remember that every action has a reaction, so don’t rob Peter to pay Pa

In case you haven’t seen it in the news recently, another conspiracy and cover-up has been discovered and is being referred to as “Climategate.” It seems there has been some manipulation of the database of historical temperature data that has been used to support the concept of global warming. A string of emails between scientists has been uncovered that indicates there has been some manipulation and/or deletion of data that did not support global warming theories, bringing into question the validity of graphs and studies that suggest the earth is warming because of human activities.

So what does this have to do with cool roofing? Can cool roofing really influence global climate? Energy Secretary Steven Chu thinks so. Some studies have shown that cool roofing can indeed help reduce urban heat islands. This may be true, but given the recent buzz noted above, is the data in those studies also suspect?

There may be some influence on urban heat islands from cool roofs, but the real and practical proven influence cool roofing has is on energy usage. Science isn’t even necessary to prove to building owners that cool roofing reduces air conditioning needs. All that a building owner needs to do is open his or her July utility bill.

Savings in summer electricity use for air conditioning is real, and even if there is some heating penalty (the idea that white roofs will prevent a building from warming up in winter), that penalty is almost always less than the benefits from reduced cooling loads.

Two main Federal tax incentives exist for installation of cool roofing, but as with any Federal government program there are qualifications that need to be met.

Residential Tax Credit

At this time, single-ply membranes are not eligible for a tax credit on residential applications. However, if additional insulation is installed during roof replacement, the cost of the insulation can be claimed as a credit.

Commercial Tax Deduction

In general, tax law allows a deduction for part or all of the cost of energy efficient building property that the taxpayer places in service between December 31, 2005 and December 31, 2013. Several conditions must be met to qualify for the commercial tax deduction:

1. The building must be within the U.S. and must meet the requirements of ASHRAE Standard 90.1-2001 – Energy Standard for Buildings Except Low-Rise Residential Buildings.

2. To qualify for the maximum total combined deduction for all lighting, HVAC, hot water, and building envelope property installed, the total annual energy and power costs of the building must be reduced by at least 50 percent.  A partial deduction is allowed for each separate building system. The IRS set the following target reductions in March 2008:

• Interior lighting – 20%
• HVAC and hot water – 20%
• Building envelope – 10%

Cool roofing is partially qualifying if it is estimated to reduce the total annual energy and power costs by 10 percent or more. The maximum deduction amount for partially qualifying property is $0.60 per square foot of the building.

3. The Performance Rating Method (PRM) must be used to compute the percentage reduction. Calculations are based on a reference building located in the same climate zone as the taxpayer’s building and containing the new building component that has been incorporated, but is otherwise identical to the reference building. The Department of Energy maintains a list of qualified software to be used to calculate energy and power costs for certification.

4. To claim the deduction, the taxpayer must obtain a certification provided by a qualified individual. The taxpayer is not required to attach the certification to the tax return, but the taxpayer must maintain proper records to establish the entitlement. A qualified individual:

• is not related to the taxpayer claiming the deduction;
• is an engineer or contractor that is properly licensed as a professional engineer or contractor in the jurisdiction in which the building is located; and
• Has represented in writing to the taxpayer that he or she has the requisite qualifications.

A certification must contain:

• the name, address, and telephone number of the qualified individual;
• the address of the building to which the certification applies;
• one of five statements (as outlined by the IRS) explaining the manner in which the building envelope property satisfies energy efficiency requirements.

By Cool Roof Rating Council

A cool roof reflects and emits the sun’s energy as light back to the sky instead of allowing it to enter the building below as heat. In many climate zones, a cool roof can substantially reduce the cooling load of the building, providing several direct benefits to the building owner and occupants:

• Increased occupant comfort, especially during hot summer months
• Reduced air conditioning use, resulting in energy savings typically – 10-30%1, and
• Decreased roof maintenance costs due to longer roof life.

Cool roofs benefit the environment and public health in additional ways. As recognition of these benefits has become more widespread, cool roof requirements are appearing in building energy codes and green building programs across the nation.

Climate Change Mitigation

Cool roofs reduce greenhouse gas emissions by conserving electricity for air conditioning; less CO2 is emitted from power plants. Cool roofs also help cool the world, simply by reflecting the sun’s energy back to the atmosphere, thereby mitigating global warming. A Lawrence Berkeley National Laboratory study found that world-wide reflective roofing will produce a global cooling effect equivalent to offsetting 24 gigatons of CO2 over the lifetime of the roofs. This equates to $600 billion in savings from CO2 emissions reduction.2

Urban Heat Island Mitigation

Cities can be 2º to 8ºF warmer than surrounding areas due to dark materials, including roofs, which absorb the sun’s light energy as heat during the day and release it at night as heat.3 This phenomenon prevents air from cooling down at night and results in higher temperatures being maintained longer. By immediately reflecting solar radiation back into the atmosphere and reemitting some portion of it as infrared light, cool roofs result in cooler air temperatures for urban environments during hot summer months.

Reduced Smog

Cool roofs, through mitigation of the urban heat island effect and reduction of ambient air temperatures, in turn improve air quality. Smog is created by photochemical reactions of air pollutants and these reactions increase at higher temperatures. Therefore, by reducing the air temperature, cool roofs decrease the rate of smog formation.

Public Health Benefits

Lower ambient air temperatures and the subsequent improved air quality also result in a reduction in heat-related and smog-related health issues, including heat stroke and asthma.

Peak Energy Savings and Grid Stability

Because cool roofs reduce air-conditioning use during the day’s hottest periods, the associated energy savings occur when the demand for electricity is at its peak. Therefore, cool roofs reduce stress on the energy grid during hot summer months and helps avoid shortages that can cause blackouts or brownouts. In addition, for building owners that pay for energy based on the time of use, they save energy – and more money – when it is at its most expensive.

Secondary Energy Benefits

Cool roofs directly reduce air conditioning use for buildings by reducing heat gain in the building below, but they also indirectly reduce air conditioning use in urban areas by helping lower ambient air temperatures. Cooler daytime temperatures mean that buildings and vehicles use less air conditioning and save additional energy. In turn, this results in a reduction in the CO2 emissions from electricity generating power plants.

The Cool Roof Rating Council (CRRC) is a non-profit membership organization. Formed in 1998, the CRRC maintains a credible, third-party rating system to measure and label the radiative properties of roofing materials. Please visit the CRRC at www.coolroofs.org.

1Energystar.gov

2 Akbar, H. (2008). Global Cooling: Increasing Solar Reflectance of Urban Areas to Offset CO2. In press, Climate Change.

3 Energystar.gov

Reflectivity, or albedo, is the percentage of the sun’s energy that is reflected by a surface. Another important measurement of a roof membrane’s performance is emittance. Emittance deals with how effectively a surface releases heat; it is the percentage of absorbed energy that a material can radiate away.

Most authorities have concentrated on reflectivity as the prime measurement of energy performance of cool roofing. However, with even the most reflective materials some energy is absorbed, and if that absorbed energy is not released efficiently it can cause a roof to heat up.

There is another measurement, called the solar reflectance index (SRI), that is beginning to get some attention. SRI combines reflectivity and emittance to measure a roofs overall ability to reject solar heat. The calculation of this index is defined by ASTM E 1980-01 and is based on some rather complicated math that includes values for solar absorptance, solar flux, thermal emissivity, the Stefan Boltzmann constant, and various other coefficients. Standard black (reflectivity 5%, emittance 90%) has an index of 0, and standard white (reflectivity 80%, emittance 90%) has an index of 100. Very hot materials can actually have negative values and very cool materials can have values greater than 100.

When all is said and done, a specific value can be calculated for any roofing product. Materials with the highest SRIs are the coolest choices for roofing.

Here is a sampling of products measured by Lawrence Berkeley Labs:

Noted roofing authority, Richard L. Fricklas, discusses PVC roofing in Buildings Magazine’s December 2009 Newsletter.

For the last year, attention seems to be more on cool roofing, LEED, and vegetated roofs rather than what the roofing system is made of or what it can do. Maybe because current roofing systems are all well established, so they’re no longer newsworthy? Several claims are being made as to which manufacturer has lowest carbon footprint and which products are truly recyclable.

To read the full article click on the link below.

PVC Roofing

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Numerous terms and ideas are used to describe products, processes and techniques that are said to be sustainable or provide high performance. Terms such as “green,” “environmentally-friendly,” “recyclable” and “long life-cycle” attempt to define the concept of sustainability. But what really is sustainability? How do you determine whether a product is truly sustainable or not?

Along with the growth of green design programs such as LEED® and Green Globes, there have been efforts by state and local governments to add sustainability guidelines to building codes. The federal government has indicated it plans to add green design guidelines to its building requirements as well.

Guidelines for many performance criteria are established based on standards. There are ANSI standards for PVC sheet roofing, for measuring emittance and for calculating a solar reflectance index. There are LEED standards that attempt to set the bar for high performance building design and construction. There are standards for wind loads and for material strength and thickness. Sustainability standards already exist for a few building products, but not for single-ply roofing. Without specific, complete standards for single-ply roofing, PVC-based products could become part of a broad category that would not accurately or effectively present the complete green picture for vinyl roofing.

The Vinyl Roofing Division of the Chemical Fabrics and Film Association has undertaken an ambitious effort to develop and obtain approval for an ASTM standard for Sustainable Thermoplastic and Thermoset Single-Ply Membrane Roofing. The process is anticipated to take another 6 – 12 months, but in the end the standard will provide solid guidelines as to what constitutes a sustainable single-ply roofing system. Stay tuned for updates as the project progresses.

The term “green roof” has become narrowly defined in recent years to refer to “vegetative roof.” But “green roof” can also mean “sustainable roof” – one that provides long-term environmental benefits that building owners want roofing systems to deliver for their high-performance facilities: high reflectivity; recyclability; able to accommodate photovoltaic systems; able to help facilities obtain LEED credits; etc. This brief video discusses these benefits and more. For additional information about green roofing, visit www.whiteequalsgreen.com.

Significant Savings Drive Demand for Cool Roofing

Cool Roofing Options and Choosing the Best Cool Roofing System

There are two primary types of cool roofing products on the market today: (1) reflective paints and coatings; and (2) single-ply roofing systems. Paints and coatings based on either acrylic or elastomeric chemistry can be an effective short-term solution for reducing energy costs, but most facility owners looking for long-term, low-maintenance solutions opt for a complete single-ply roofing system.

Many roofing products are on the market, which can make choosing the right one a challenge. Fortunately, several objective tools are available to help with the process. Choosing a system from the approved list of products in the EPA’s ENERGY STAR® Roof Products Program or from the Cool Roof Rating Council (CRRC) ratings chart is a good way to narrow down the selection process. Products on the ENERGY STAR list undergo rigorous testing before approval to ensure that they meet the established standard for reflectance.

In addition, the ENERGY STAR Roof Products Program has developed an energy savings calculator that projects the potential savings from installing a cool roof compared with alternative “non-cool” systems.

Here is a short list of important factors to consider when selecting a cool roofing system:

1. Reflectance/emittance performance, both initial and after three years.
2. Long-term track record of durability and performance.
3. A good warranty backed by a solid, well-established manufacturer.
4. Climate and weather extremes in a given location.
5. Maintenance requirements and ease of repair.

In our next installment we will discuss: Single-Ply Cool Roofing Systems

How Cool Roofing Works

The trend may be new, but mankind has understood for centuries that white or light-colored surfaces are cooler than dark surfaces. Those stunning, ancient, all-white Mediterranean and Middle Eastern cities are not only aesthetically pleasing, they are also surprisingly cool and comfortable even on the hottest days of summer. Economic and environmental pressures have inspired a renewed interest in the heat-reflective properties of white surfaces, and recent research into the dynamics of urban heat islands, or UHIs – the phenomenon where even small cities are typically three to ten degrees warmer than nearby suburbs and countrysides.

The UHI chain of cause and effect is clear: As temperatures increase, more electric power is needed for air conditioning and more fossil fuel is consumed, which leads to higher levels of air pollution. The probability of smog rises five percent for each one-half degree increase in ambient temperature above 70ºF.

Meanwhile, Oak Ridge National Laboratory (ORNL) has conducted several related studies to evaluate various materials for solar reflectance and emittance.

• Reflectance, also known as albedo or reflectivity, is the percentage of solar energy reflected by a surface. The higher the percentage of reflectance, the more heat energy will be reflected from the surface.

• Emittance, or emissivity, is the percentage of heat energy a material can absorb and then shed in the form of infrared radiation. Materials with low emittance tend to heat up more easily because they collect and trap heat. It is interesting that while many black materials have very low reflectance, they can exhibit very high emittance.

Although there is no industry-wide definition of a cool roof per se, the Environmental Protection Agency’s (EPA) ENTERGY STAR® Roof Products Program has established a minimum standard for products to qualify. The EPA standard requires that low-slope roof products have an initial reflectance of at least 65 percent, and a reflectance of at least 50 percent after three years of weathering. The ENGERGY STAR Program also requires products to carry warranties similar to, or better than, those offered by the same manufacturer for similar non-reflective roof products. ENERGY STAR ratings can be found on their web site, www.energystar.gov.

In our next installment we will discuss: Cool Roofing Options and Choosing the Best Cool Roofing System.