Choosing the Best Insulation
- By Janet Wiens
- December 1st, 2009
When the weather gets colder, individuals select the best garment to keep warm. If it is rainy, we do the same thing in order to keep dry. Just as humans select the best insulation to protect themselves, buildings need insulation to maximize energy efficiency and to contribute to other critical requirements, such as sound control.
Facility personnel have hundreds of choices when it comes to selecting the best insulation for a project. Some products have been on the market for decades, while others are relatively new. Following some key points will help to ensure that the selected insulation will successfully serve its intended purpose for many years.
Making the Choice
Insulation comes in many forms, including batt, blankets, boards, granular, and loose fill. The optimum time to select insulation is during the preliminary design phase, when other energy-related and system decisions are being made.
“Facility personnel tend to use insulation that they have used on previous projects,” said Darrell Winters, director of codes and standards for the North American Insulation Manufacturers Association (NAIMA). “There is wisdom in using what you know. At the same time, many colleges and universities are considering their insulation alternatives based on a desire to maximize energy efficiency.”
Winters said that it is critical to look at the building — whether it is a new project or a renovation — as a whole. Individuals must determine how the insulation works in concert with the building system, use, and other components. Considering how wall, floor, and ceiling insulation works with all features is critical and cannot be overemphasized.
“The building’s structure, use, and geographic location have an obvious and significant impact on the type of insulation that is used,” Winters said. “A structure may be more adaptable to blown rather than batt or board insulation in certain areas. A project’s geographic location and the associated heating and cooling loads and requirements also have a substantial impact.”
Efficiency and Environmental Concerns
An insulation’s R-value, determined by a federal government rating system, relates to energy efficiency. The R-value measures the product’s ability to resist heat traveling through it. Higher R-values are desirable because it means that the product offers better thermal protection than a product with a lower R-value.
A product’s environmental properties must also be considered, including how and where it is manufactured, the recycled content, and the overall content. Winters noted that a product’s green attributes are more important today than at any point in time. The association he works for represents manufacturers for fiberglass, slag wool, and rock wool products, and he notes that all three product types have positive environmental attributes.
Sound control is also an issue. A music building or theater has vastly different requirements from a classroom or administrative building. Insulation, again, works in concert with other building components to provide the required level of sound absorption and control.
Look at the Price Tag
Cost is the final factor, as it is for virtually every building product. Facility personnel must weigh an insulation’s benefits in light of other building features and the associated budgets for these requirements.
The Longwood University Approach
John Wood, director of capital planning and construction at Longwood University in Farmville, VA, agrees with Winters that insulation decisions must be made at the beginning of a project. “We ask our architects and engineers to recommend insulation for our larger projects,” he said. “All of our new buildings and our renovations must be to Leadership in Energy and Environmental Design (LEED) standards, so energy efficiency and the role of insulation in that equation is very important.”
The new Health and Fitness Center at Longwood is the first building to achieve LEED Certification on the institution’s campus; Moseley Architects served as the Architect of Record.
Computer modeling is used to help determine the optimum insulation for larger projects, and Wood noted that most computer modeling solutions go well beyond ASHRAE standards. The University’s larger building projects typically involve a combination of batt and extruded polystyrene insulation. For small projects, he says that the facility staff typically uses what they know, which most often involves lay-in insulation for walls and ceilings.
The new Health and Fitness Center illustrates the facility department’s approach to facility projects. The structure houses all recreation components, which were previously spread out around campus, into one very efficient building. The planning team used the LEED Green Building Rating system to make design decisions, and energy efficiency was a key priority. The 74,683-sq.-ft. building envelope was enhanced to include more roof insulation than normal, and five-in.-thick polyisocyanurate foam, rated for an aged value of R-25 or better, was used for this purpose. More efficient batt insulation was also used for the walls. Insulation was protected during construction to prevent dirt and moisture from entering the building during installation, which could have occurred if the insulation had been minimally protected when on site.
“We received a LEED Gold rating for our facility, and selecting the right insulation was part of achieving that rating,” said Wood. “This building is very energy-efficient and illustrates the sustainable standards we are using at Longwood.”