Insulation R-Values Explained
Insulation is a heat-resistant material placed inside walls, floors, attics, and crawl spaces that prevents hot air from entering the house during the summer, and hot air from leaving the house during the winter. Insulation’s effectiveness is measured by its r-value, or measure of thermal resistance. R-values are important to consider when choosing a type of insulation, as insulation with higher r-values can impact price of the insulation, as well as comfort in the home, and overall lifetime value and energy efficiency. Critter Authority offers all types of insulation, with many different r-values, in the Richmond, VA area. If you are interested in getting your insulation redone, contact our team of experts to get started today with a FREE estimate at (804) 492-2804!
What is an R-Value?
R-values are the measure of thermal resistance in a unit of insulation, or how well it can resist heat. A higher r-value means that the insulation can resist heat better. R-values vary based on the type, thickness, and density of the insulating material. Typically, the higher the r-value, the more effective the insulation is, but also the higher the cost.
The equation to calculate R-values is:
R-value = temperature difference x area x time / heat loss
Fiberglass batts and rolls typically have an r-value of 2.9-3.8 per inch.
Blown-in cellulose insulation typically has an r-value of 3.1-3.8 per inch.
Open-cell spray foam insulation has an r-value of 3.8 per inch, while closed-cell spray foam has an R-value of 7.0 per inch.
Foam board insulation’s r-value depends on what type of foam is used. Rock Wool board has an r-value of 4.2, as does expanded polystyrene. Extruded polystyrene has an r-value of 5.0, while polyisocyanurate foam board has an r-value of 6.0
Why Do R-Values Matter?
R-values matter because they are an easy way to help you determine which type of insulation will provide you with the most energy efficiency. Having the right r-value for your home can ensure that your HVAC systems aren’t straining to keep your home comfortable, which means that your heating and cooling bills will be lower each month. Over time, less strain on your HVAC systems can prevent costly repair bills, and it can allow your HVAC system to function longer without needing a replacement. It’s important to note however, that the higher your R-value is, does not automatically mean the better that insulation is for your home. Different regions require different r-values. The US Department of Energy has divided the US into seven different regions based on r-values required to maintain a comfortable temperature in the home.
R-Value Requirements by Region
Location and climate can affect the r-value of insulation needed to effectively control the temperature in your home. For example, region one in Florida requires a lower r-value needed to insulate an attic, at R30 to R49. Note that this doesn’t mean that the insulation needs to have an R-value of 30 per inch, but rather the attic insulation as a whole needs an R-value that high. For example, if you have an r-value of 5 per inch, then your attic insulation in region one would have to be at least 6 inches thick (6 inches x R-value of 5 per inch= R-value of 30) in order to effectively insulate your home.
Critter Authority’ service area of Richmond, Henrico and Hanover places us firmly within Region 4, as defined by the US Department of Energy. Region 4 requires an r-value of R38 to R60 in attics, R13 to R21 in walls, and R25 to R30 in floors and crawl spaces. It’s important to adhere to these guidelines to avoid under-insulating or over-insulating your home.
How R-Values Apply to Different Areas of Your Home
R-values are not a one size-fits-all solution, as different areas of the home require different r-values. The Stack Effect moves hot air upwards throughout the home, letting most of the heat inside the home escape through the roof. A higher r-value is essential in the attic to prevent heat from leaving the home during the winter, when you want to keep that warm air inside the home. Walls, floors, and crawl spaces often require a lesser r-value, as the insulation in these areas are mostly to keep the temperature consistent across the home, not prevent the heat from escaping like in the attic.
Choosing the Right R-Value for Your Home
Choosing the right insulation and the right r-value for your home depends on your climate, as well as your home’s design and whether or not you already have a working insulation job. You might only need to add a few inches of insulation to an attic that already has some, but if you are insulating a new build, this might require more insulation to reach an acceptable r-value. If you need new insulation installed in your home in Richmond, Henrico or Hanover, then contact the insulation experts at Critter Authority. Our trained technicians will carefully inspect your home, assess your insulation needs, and then provide you with recommendations on your next steps. We can remove damaged or settled insulation, clean the area to remove any damage done by pests or wildlife, and then replace the insulation with newer, highly effective material. Contact our team to get started today with a FREE estimate at (804) 492-2804!