Case Study #1

POLYISO EMERGES DECISIVE WINNER IN COMMERCIAL ROOFING STUDY

Polyiso insulation emerged as the decisive winner over extruded and expanded polystyrene insulations in a recent study that compared the cost benefits of using various insulation products in commercial roofing systems. The study--completed by Energy Conservation Management (ECM), an independent energy research and analysis firm in Baltimore, Maryland--revealed pertinent information about factors, such as return on investment, installation costs and payback rates, which determine the cost effectiveness of using different insulation products in construction applications. The bottom-line numbers showed why polyiso has become the leading insulation product in the marketplace today, as well as why it is the preferred choice for specifiers, architects, and contractors nationwide. As you review the following information, you will see that polyiso's performance and cost benefits are outstanding!

The Study

Three one-story buildings in Boston, Houston, Phoenix, Seattle and Washington, D.C. were modeled. Using an hourly energy simulation program called micro-AXCESS 10.2 D, analyses were performed to determine the energy usage of each building. Once the base models were built, only changes in the roofing insulation were simulated. The rooftops of the three models in each city were run using different levels of insulation: a minimal insulation level, a "typical" insulation level for each city and an ASHRAE 90/1 level. The energy output for each city was run with a utility rate file to obtain the utility costs for each scenario. These utility costs were then compared with the installation costs of polyiso and expanded and extruded polystyrenes to determine payback rates and return on investments.

The Results

Returns on Investment (ROI)

According to ECM, the returns on investment for polyiso ranged from 3.1 to 43.5 times higher than those for both extruded and expanded polystyrene which means that one would receive a higher percentage of return on the amount of money initially invested with polyiso than they would with extruded or expanded polystyrenes.


Bars reaching 100% are actually higher than 100%. ROI polyisocyanurate for Houston Typical is 2324%. ROI polyisocyanurate for Houston Ashrae is 454%. ROI polyisocyanurate for Washington, DC Typical is 678%.

"Polyiso is in and of itself a good investment because the percentage of investment one can recoup over a given period of time with polyiso is much higher than with extruded or expanded polystyrenes."

 

Payback Rates

The paybacks for using polyiso were all at least three times faster than those for extruded polystyrene -- six of the ten cases pay back within five years.


"Polysiocyanurate was shown to be the more profitable investment over polystyrene in all five cases, for all R-values and in all cities," said Tara Dorr, author of the report and energy analyst for ECM, "because the paybacks for increasing the levels of insulation from the baseline one inch perlite with an R-value of 3.89 to higher R-values showed themselves to be very reasonable."

 

Installation Costs

Installation costs ratios for polyiso ranged from 39-48 percent, which means that the cost of increasing the insulation from the baseline level to a certain R-value in each case was 52-61 percent less expensive with polyiso than with extruded polystyrene.


"The installation costs for increasing the R-value of a roof scenario using polyiso insulation was less expensive than using polystyrene to achieve the same R-value," said Dorr, "There are higher material and labor costs due to the underlayment and cover board needed when using polystyrene and the increased thickness of insulation needed to achieve a certain R-value because of the lower 'R per inch' value of polystyrene."

 

Cost Factors Defined

Return on Investment - Percentage of investment that will be recouped over a given period of time.
Payback Rates - The length of time and years it takes to recoup initial investment.
Installation Costs - The dollar cost of installing products or materials based on materials and labor.

The Polyisocyanurate Insulation Manufacturers Association (PIMA) produces technical bulletins in an effort to address frequently asked questions about polyiso insulation. PIMA's technical bulletins are published to help expand the knowledge of specifiers and contractors and to build consensus on the performance characteristics of polyiso. Individual companies should be consulted for specifics about their respective products.

The Polyisocyanurate Insulation Manufacturers Association (PIMA) is the North American trade association that advances the use of polyisocyanurate (polyiso) insulation. Polyiso is one of the nation's most widely used and cost-effective insulation products available.

PIMA's membership consists of manufacturers of polyiso insulation and suppliers to the industry. Our members account for a majority of all of the polyiso produced in North America.

 

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