Roof and Wall Benefit Analysis
R-50 Systems provides the most advanced insulation technology in the building market today. There are numerous benefits to the R-50 System insulation products vs. the standard building envelope insulations now available.
In the United States, many governing bodies, such as IBC, BOCA, and GSA have mandated considerably higher R-value levels for insulation in building roof/wall construction. With these mandates come immediate consequences which will be discussed in this report along with the outstanding benefits of the R-50 Systems insulation products.
The buildings sector accounts for approximately 41% of the total energy consumed in the United States. Approximately 37% of this “building” energy is used by the HVAC systems to heat and cool the facilities. A large fraction of this energy is lost through the building envelope. Continuing advances in building envelope technologies play an important role in reducing overall building energy consumption.
Roofing/wall systems is an area of the building envelope in which significant advances have been made. Better insulating properties and improved solar energy reflectance are but two characteristics that have shown significant gains. One particular technology that has demonstrated results for improving insulation is Vacuum Insulated Panels (VIP) and modified units of VIP.
R-50 insulations are very high performing insulations. The products reduce the building energy use and also reduce the thickness of insulation required to achieve thermal goals. R-50 Systems provides an insulation R-value factor that meets or exceeds the standards set today by the local/regional, national, and federal guidelines. The factory fabricated system for roofs consists of a vacuum insulated panel set between two fire-rated boards. The system is fireproof and water resistant. R-50 Systems can be installed on most roof deck types and can support all conventional low-slope roof systems. R-50 insulation is produced in plant to provide extreme insulation R-values at 1” to 1.5” thickness.
Buildings with curtain wall facades have large expanses of vision glass and aesthetics. A curtain wall system can be designed for energy efficiency, and does not need to have an overall poor thermal performance. Glass curtain walls generally have lower thermal performance compared to other typical enclosure systems. The introduction of R-50 Systems VIP technology may provide buildings with configurations similar to 40% glass and 60% spandrel with greater energy efficiency by reducing the total heat consumption. To a great extent, we are now able to add significant thermal insulation for EFIS applications.
• Vacuum insulated panels enhance the thermal performance of typical curtain wall systems, compared with conventional insulated solutions.
• Increasing the thickness of conventional insulation will not be efficient enough to meet the overall R-value requirements for buildings.
• The vacuum insulated panels reduce the condensation risk compared with conventional insulations.
2. Construction Consideration – Value Added
The R-50 Systems products provide extremely high R-value insulations to meet today’s mandates in a 1.5” or less thickness. Conventional options, such as polyisocyanurate, would potentially need up to 15” of height to reach the R-value objective. This makes the conventional insulation approach impractical, as the use of polyisocyanurate insulation, for example, would raise the roof surface up to or above the existing flashing system, thereby requiring extensive modifications to the counter flashings, masonry, window sills, and equipment pads. Also, the wider the interior insulation, the less usable space for living or operations. The obvious alternative is to use an insulation system that will function better and keep the construction price well below the traditional options, as extensive building modifications are no longer necessary. The savings experienced by reduced building modifications are significant no matter how large or small the structure, and must be considered when designing the roof and wall system.
• Camden Courthouse – GSA1
– R-50 VIP roof installation Green Proving Ground Certified2
– Per Oak Ridge National Laboratories, use of R-50 Systems roof insulation, without requiring building modifications, resulted in saving $200,000 (10,000 s.f. area).
3. Energy – Potential Savings with R-50 Systems Insulations
As energy prices increase, the energy-related savings also will increase. Additional analysis suggests that the costs and benefits vary significantly depending on perspective. An owner/operator such as the GSA might yield strong financial benefits from replacing non-conforming insulation (NCI) on roofs of their assets with energy efficient roofs. Based on R-50 Systems insulation vs. conventional insulation, 6 million square feet of roof/wall area potentially has the benefit in energy savings and reduction in construction costs of approximately $60 million or approximately $10 saved per square foot of building area.
The various aspects considered in the cost-benefit analysis are only part of the actual impact of an R-50 VIP roof. The value and productivity of the building itself could add to the already positive market acceptance of R-50 assemblies. Basic savings on yearly energy costs can be estimated based on the cost of local energy prices, not knowing future costs.
4. Long Term Benefits
Based on the Dow Chemical Company White Paper of November 2009 , “… the average life of a roof system in North America is 16 years.” The cost of roof replacement increases every year, and by the year 2030, the average will be in the area of $30.00 per square foot. Roof replacement includes roof insulation. However, if the insulation did not require replacement, R-50 Systems insulation attributes make it feasible, in many cases, to replace only the membrane on top of the insulation. Then, the cost for roof replacement would be reduced to a minimum square foot cost resulting in significant savings.
Example. Assuming the average industrial/commercial roof is 20,000 s.f.:
Example 1 – 20,000 s.f. total roof replaced @ $30.00/s.f. = $600,000.00
Example 2 – 20,000 s.f. replace roof membrane only @ $10.00/s.f. = $200,000.00
5. Economic Parameters
The economic parameters of each site must be carefully analyzed to determine the cost effectiveness of Vacuum Insulated Panels in a roofing or wall application. Factors that contribute to the economically viable use of Vacuum Insulated Panels include, but are not limited to, the following:
• High unit costs of energy in terms of $/kWh of electricity or $/mcf of natural gas.
• Extreme climate zones are found in the North or the Southwest of the United States.
• Single story buildings with large roofs such as flat office buildings or large maintenance facilities.
• High costs of modifying the building to reach the desired R-value using conventional insulation. Such modifications might include raising mechanical equipment, having to change the brick and sills around windows, or building up parapets around the roof edges to account for added thickness of conventional insulations.
• High rise buildings with curtain walls and large expanses of glass.
It must be emphasized that a careful analysis must be conducted for each building unit roof/wall to determine the overall cost-effectiveness of reaching a certain R-value by using R-50 Systems roof insulation versus conventional roof insulation.
6. Environmental Impact
R-50 Systems roof/wall installation performs year after year. Not only does it reduce the total annual energy consumption of the building, but the longer a roof/wall can be kept in use, the more it contributes to the overall sustainability of the building by delaying the impact of eventual replacement. Deferring a roof replacement can save hundreds of thousands of dollars while the stability of wall insulation will continue to reduce costs for many years.
R-50 Systems will reduce downstream waste during construction, maintenance, and demolition phases because the insulation is designed to be reusable. Sustainability with recycling is also a major plus for R-50 Systems insulation. Reduction of landfill costs, as well as environmental costs, add to the value added performance.
According to the GSA Green Proving Ground
VIP technology has the potential to significantly reduce energy use when applied to reroofs in cold-climate low-rise installations where roof/wall area is a significant fraction of the overall building envelope surface area.
ENERGY EFFICIENCY – U.S. Department of Energy simulation studies have shown that increasing roof insulation from R-15 to R-50 reduces heating losses through the roof significantly (5 to 10 times higher R-Value). This benefit is best realized in heating dominated climates.
COST EFFECTIVENESS – VIP insulation system provides:
• Short term: Eliminate building modifications
• Long term: Decreased energy costs
Summary of Findings by National Research Council of Canada
• Based on sound principles of the basic physics of heat transfer, it is realistic to expect five to ten times larger R-value/in. from VIPs than from traditional thermal insulation materials used in building envelope construction.
• Use of VIPs in energy-efficient building envelope construction is a real possibility and an attractive proposition for the roofing industry.
• Recent upgrades of building energy codes in North America offer an historic opportunity for the construction industry to integrate VIPs in building envelope construction.
• Available field performance evaluation results provide encouraging indicators for the long-term thermal performance of VIPs in both roof and wall constructions.
• Application of VIPs provides highly efficient thermal insulation in building envelope construction. The advantages include higher thermal resistance, reduced thickness of building components and recyclable materials.
• Researchers across the world, including those from National Research Council of Canada, are working with construction industry stakeholders to exploit the advantages and address the challenges.
• R-50 insulation is more cost effective than traditional insulation, which requires extensive building modifications to achieve similar high R-values.
• R-50 insulation reduces 60% ± of long-term replacement costs.
• The total roof/wall system becomes sustainable with the use of R-50 insulation.
• R-50 insulation makes it economically feasible to re-roof with high R-rated insulation to drastically reduce annual energy consumption of buildings.
• R-50 insulation is a perfect insulation to be used under a green vegetative roof.
• R-50 insulation systems are 99% recyclable.
• R-50 insulation reduces landfill and environmental costs.
• R-50 insulation provides a lifetime roof insulation system.
• R-50 insulation is fireproof and waterproof.
1. Oak Ridge National Laboratory Report to GSA: “Vacuum Insulated Panels in a roofing application, GSA Federal Courthouse, Camden, NJ”
Dan Howett, P.E., Therese Stovall, Mahabir Bhandari, PhD, Kaushik Biswas, PhD
2. GSA Proving Ground Program Certification
3. United States, November 2009 White Paper
The Dow Chemical Company
4. U.S. Department of Energy simulation studies
5. National Research Council of Canada
Vacuum Insulation Panels (VIPs): An Historic Opportunity for the Building Construction Industry – By Phalguni Mukhopadhyaya, Sudhakar Molleti, and David van Reenen.
Printed in RCI Interface Magazine August 2014