Proper insulation in your home will keep you warmer in the cold months, cool in the hot months, and can save you money. Understanding R-values and applying that knowledge to your home can help you optimize your home’s energy efficiency.
The EPA calculates that a typical homeowner can save up to 15% on annual heating and cooling costs by applying insulation and sealing their home in the right areas. You can check out the EPA Energy Star site to understand why you may want to seal and insulate, energy efficiency methodologies, and defining problem areas.
As with most products, there are several different types of insulation available for almost every application and scenario. Using the right product to optimize the R-value is the key to increasing energy efficiency.
Explaining R-Value
The R-value associated with insulation products is a rating given with respect to the insulation’s resistance to heat flow. What that means is how well the insulation prevents the movement of heat flowing into or out of your home.
Higher temperatures move to lower temperatures, so that means we want to keep the heat from escaping from our homes in the colder months and from getting into our homes in the hotter months. Insulation and its R-value play a big part in controlling that energy flow. The higher the R-value, the higher the resistance to heat flow, which leads to better performance.
Choosing the best product
Depending on whether you live in the northern part of the country or in the south, R-value recommendations will vary. Choosing the right product to meet your needs and meet recommended R-values is not a one-size-fits-all solution.
The United States Department of Energy has developed recommendations for the types of products and recommended R-values across several regions of the country. In general, this means that what is required for International Falls, Minnesota, will be different from Miami, Florida. The map below shows regional R-value recommendations.
R-Value recommendation map sourced from EPA Energy Star
Within each zone, there are R-value recommendations for specific systems in the home. Attics will have a higher R-value recommendation than floors, for example. The chart below has the specific recommendations for each of these zones as shown on the map above.
R-Value recommendations for specific home systems – homedepot.com
By using the guidance above, you can make decisions on materials for your next insulation project or confirm that the systems in your home are adequately insulated.
Typical insulation types and R-value ratings
Blown-in or loose-fill insulation
This type of insulation is typically an attic application. The insulation materials are loaded into a machine that mixes and fluffs them up so they can be blown into an attic space. This process allows for access to hard-to-reach areas and is relatively cost-effective. Fiberglass and cellulose are the primary materials used for this process.
Blown-in fiberglass insulation application
Fiberglass loose-fill insulation is primarily glass that is spun to make the fibers that make up the loose fill. Fiberglass insulation resists moisture absorption, which helps to resist mold, mildew, and other fungal issues. It does not do much with respect to air leakage or the sealing of gaps or openings. Fiberglass loose-fill insulation averages an R-value of R-2.2 to R-3.8 per inch of application.
Cellulose loose-fill insulation is made up of recycled cardboard and newspaper, which is additionally treated with chemicals that make it resistant to fire, rodents, and other pests. Cellulose insulation works well to settle in and combat air leakage. In studies using blower door testing, cellulose loose-fill insulation has one of the highest resistances to air leakage.
Cellulose is a bit less DIY-friendly. It is harder to install and very dusty. Over time, the product settles, which reduces its overall R-value. Cellulose R-values tend to be higher than fiberglass’s, ranging from R-3.2 to R-4.0 per inch.
Airborne particles from both fiberglass and cellulose can pose a health hazard to people when they are installing them. As with all products, installers should make sure they are using the recommended PPE (personal protective equipment) when installing.
Insulation Blankets
Insulation blankets are typically the most inexpensive insulation options. Commonly referred to as “batts,” this product comes in rolls that can be cut to the desired length. Batts are also designed to fit between wall studs, attic joists, or floor joists, come in varying thicknesses, and are typically made of fiberglass. Insulation blankets are DIY-friendly and easy to install.
Fiberglass batts come either with or without a vapor barrier attached to them. The downside to fiberglass batts is consistent installation, especially around the edges and corners. R-values for insulation blankets range from R-2.9 to R-4.3 per inch of thickness.
Fiberglass insulation installed in a wall structure
Spray Foam
Spray foam insulation is designed to both insulate and reduce air leakage. This product is sprayed into place, where it expands, seals, and hardens. Spray foam installation requires specialized equipment and is not typically a DIY application. Spray foam works well in most applications. The downside is that it is one of the most expensive alternatives, but it has a higher payoff in the long run. R-values for spray foam range from R-3.5 to R-6.5 per inch, depending on whether it is an open- or closed-cell product.
Installing spray foam to a wall structure
Foam Board Insulation
Foam board insulation, like spray foam, has a high resistance to heat flow and leakage. The tight pore structure of foam board makes it resistant to moisture intrusion. We typically see this type of foam installed on the perimeter of basement walls. Foam board insulation typically comes in 4x8-foot rectangular sheets that are easy to work with and cut to size. While providing high R-values, foam board insulation does not do a very good job of sealing cracks or openings. It has R-values that range from R-4.0 to R-6.5 per inch of thickness.
Summary
Insulation is an important component that can save you money while protecting you from outdoor temperatures. Choosing the right product for your needs is important when updating or replacing insulation in your home.
At HomePro Inspections, our home inspectors are trained to inspect all areas of the home. When performing a home inspection, our home inspectors observe and document the type and approximate depth of the insulation where it is accessible. Recommendations are made depending on our findings.
Visit our website to learn more or to schedule your home inspection in the Rochester, Owatonna, and Faribault, MN areas. You can contact us today at (507) 202-8942 or utilize our online “Schedule Now” feature to set up an appointment.