What's In Your Attic?

Winter is on its way and, with it, so come the frigid temperatures. Do you know what’s in your attic?…or walls?…or floor? Hopefully the answer is insulation. In the United States, heating and cooling account for 50 to 70% of all energy used in the home. A lot of that energy is being wasted because of inefficient building practices. Ensuring proper insulation in your home can make you more comfortable, save money and reduce the burden our limited energy resources. Here are a few things that you should know about insulation.

How Insulation works

Heat naturally travels from warm to cold space through conduction, convection and radiation. In winter, heat moves from our living spaces to wherever it is colder, typically outdoors. This lost heat must be replaced by a heating system to maintain comfort. In the summer, heat moves from outdoors in and must then be removed by an air conditioner. Insulating decreases the heating and cooling that is needed by providing an effective resistance to the natural flow of heat. This thermal resistance is known as the R-value. The R-values vary widely depending on the type of material, its thickness and density. The higher the R-value, the more effective the insulation.

Types of Insulation

Blanket or Batt insulation is traditionally made of mineral fibers or rock wool, but are now available in cotton, sheep’s wool and hemp. They are available in a variety of widths and are available with or without vapor retardant facing. Because of its availability and ease of installation, blanket insulation is a great choice for the homeowner.

Loose Fill insulation is typically made from cellulose (recycled paper), fiberglass or rock wool. These loose fibers are blown into walls and attics using pneumatic equipment, usually by professionals. Loose fill can be packed in to existing walls and irregularly shapes areas, making it an excellent option for retrofits on older homes.

Foam insulation is sprayed in liquid form using special equipment by professionals. This insulation comes in open or closed cell varieties. Open cell foam allows water vapor to pass through, but has a lower R-value. Closed cell foam is a better choice when space is limited.

Rigid insulation is made from plastic foams and is molded into board forms. Rigid foam is often used on foundation walls.

Insulation Fun Facts

• Insulation reduces average home heating and cooling costs by around 20%. [1]
• Insulation currently in place in U.S. buildings reduces the amount of carbon dioxide by 780 million tons each year. [2] This is the equivalent to the electricity use of over 90 million homes for one year [3] 
• For every Brittish Thermal Unit (Btu) consumed in the production of insulation, 12 Btus are saved each year by the use of insulation. [4]
• All insulation products installed in U.S. buildings save consumers about 12 quadrillion Btus annually, or about 42% of the energy that would have been consumed with no insulation in place. [5]
• This is the equivalent of 40 million Btus or 7 barrels of oil per person per year. [6] This is the equivalent of 28 barrels of oil saved by each U.S. family of four per year. 
• Energy efficiency through insulation is the simplest and most cost effective way to reduce energy use and greenhouse gas emissions.  [7]

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[1]  “Insulating Your Home: Save Energy and Money,” Better Homes and Gardens (Better Homes and Gardens Home Information System, 1995), p.1

[2]  Green and Competitive: The Energy, Environmental and Economic Benefits of Fiber Glass and Mineral Wool Insulation Products. Energy Conservation Management, Inc; The Alliance to Save Energy; Barakat & Chamberlin, Inc., June 1996.

[3] EPA Greenhouse Gas Equivalencies Calculator – www.epagov/cleanenergy/energy-resources/calculator.html

[4] Green and Competitive Report: Energy Conservation Management, June 1996

[5]  Green and Competitive Report: Energy Conservation Management, June 1996

[6] EPA Greenhouse Gas Equivalencies Calculator – www.epagov/cleanenergy/energy-resources/calculator.html

[7] A Cost Curve for Green House Gas Reduction, The McKinsey Quarterly 2007, Number 1.

About the Author
Tim DeLuca is Weatherization Inspector for 4CORE, is native of the planet earth and has been living in Colorado on and off since 1995. After studying Business at the University of Cincinnati, he moved to Fort Collins, were he studied Fine Arts and Design at Colorado State University. He then began to pursue his love and fascination with carpentry, construction, design, engineering, and energy efficient building techniques. Most recently, Tim was the Crew Leader for a group of Weatherization Installation Technicians through an apprentice program offered in partnership with Americorps, the Southwest Conservation Corps and 4CORE. After one successful year, he was hired on as an Inspector at 4CORE. In his spare time, Tim enjoys spending lots of time with his family, preferably outdoors.