Drawdown – Insulation

This is the second in a series of posts presenting the work of Project Drawdown. We’ll focus on Buildings and Cities, however if you would like to explore more about Project Drawdown, we encourage you to visit their website.

What is Project Drawdown? The intention of the founders is to identify, analyze, and develop a database of the most effective solutions already in place for arresting and reversing global warming. Can these solutions be scaled, and if so, what are their impacts? What’s the ultimate price tag — what are the costs and savings related to each solution?

“Drawdown Fellows include 75 individuals from twenty-two countries. Forty percent are women, nearly half have PhDs, and others have at least one advanced degree. They have extensive academic and professional experience at some of the world’s most respected institutions.”

Nearly all of the solutions presented by Project Drawdown result in “regenerative economic outcomes that create security, produce jobs, improve health, save money, facilitate mobility, eliminate hunger, prevent pollution, restore soil, clean rivers, and more.”

INSULATION

“Heat always moves from warmer areas to cooler areas, until a temperature equilibrium is reached. This heat flow presents a central challenge when keeping buildings within a desirable range of 67 to 78 degrees Fahrenheit. To close the gap on unwanted heat gain or loss and maintain comfortable room temperature, we use more energy. Air infiltration accounts for 25 to 60 percent of energy used to heat and cool a home—energy that is simply wasted.

By better insulating a building envelope, heat exchange can be reduced, energy saved, and emissions avoided. What makes insulation effective is its capacity for thermal resistance, measured as R-value—the higher the better. Ideally, a building’s thermal layer should cover all sides—bottom floor, exterior walls, and roof—and be continuous. Sealing gaps and cracks is also critical to a more effective building envelope.

Insulation is one of the most practical and cost-effective ways to make buildings more energy efficient—both in new construction and through retrofitting older buildings that often are not well encased. At relatively low cost, insulation results in lower utility bills, while keeping out moisture and improving air quality.”

 (Source: http://www.drawdown.org/solutions/buildings-and-cities/insulation)

Here in Georgia, we’ve worked closely with builders to deliver energy-efficient homes to our clients. With minimal additional cost and time investment, we make sure our foundations, walls, and roofs are well-insulated; that all of the joints and seams and any other gaps are caulked and sealed; and that all thermal bridges are considered and addressed. Furthermore, high-performance windows help to reduce heat transfer (stay tuned for an upcoming post about the drawdown potential of “smart glass”).

In residential design, we have moved toward using 2×6 studs at 16″ on center for exterior wall framing. This deeper, wider cavity allows for more insulation fill within the exterior walls and less thermal bridging where studs meet exterior wall sheathing. We like to use blow-in cellulose insulation in these exterior wall cavities, as it fills the nooks and crannies of these spaces with a dense insulation and is made from recycled materials.

Spray-in icynene foams are commonly used and are very effective at providing a great insulation barrier, sealing all of the little holes, particularly in roof areas and crawl spaces where gravity would tug at blow-in products such as cellulose. However most all of these spray-in foams currently available contain isocyanates, including methylene diphenyl diisocyanate (MDI), which are toxic VOCs during the installation process. Manufacturers claim that once these foams harden, the chemicals become inert, however much depends on the proper mixing of the chemicals during installation to achieve proper hardening in order to stop the off-gassing process. In the event of a fire the spray foam insulation would off-gas, and in remodel jobs there is risk of having these particles enter the air, posing a threat to workers. There is some emerging work on plant-based spray-in foam insulation with soy and caster oils used as the base instead of petroleum-based chemicals, however they are not commonly available at this time. We hope this is one area in which we’ll see a big leap forward over the coming years.

Drawdown’s analysis suggests that by 2050, if 54% of existing residential and commercial buildings install insulation, it would result in: