Understanding Insulation R-Values

Many San Antonio homeowners are very well educated on many things in today’s housing market. Market values, projected appreciation, and real values are just some of the bevy of statistics available at the touch of a button for San Antonio’s discerning home buyer. This is of course no different when it comes to insulating the San Antonio homes being bought, sold, and rented at blinding speed. However, while most San Antonio homeowners understand insulation and can hold their own when their chosen San Antonio insulation professional is appraising their existing or planned insulation, not many understand exactly what they are looking for in insulation or even its basic components.

This is where something called R-value comes in, and R-value is very important to attic insulation. While there is a math formula that is used to calculate R-value, we’ll be speaking specifically about what R-value is, not how to calculate it, because, after all, today’s home buyer is buying the insulation, not designing it. Essentially, R-value is a measure of thermal resistance, and anyone who has lived in San Antonio long enough understands the value of great thermal resistance when those brutal summers come along. R-value is the ratio of the temperature difference across an insulator and what is called the heat flux. Heat flux itself is the rate of heat energy through a given surface. If you’re scratching your head, don’t worry, it’s all just complicated ways of saying why the R-value of any given insulation is important. In layman’s terms, the R-value is just the value of the insulation and a rating on how well it performs in both keeping outside air out and conditioned air in. Basically, R-value is just what allows insulation to, well, insulate.

As different R-values correspond to different levels of insulation, Energy Star recommends different R-value for different areas of the country. San Antonio is listed in “Zone 2,” which corresponds to needing an R-value of R30 to R60, R25 to R38, and R13 to R19 in an uninsulated attic, insulated attic, and floor, respectively.

Of course, the R-value of your insulation is important for more than just your peace of mind. R-value can also be necessary for determining eligibility for tax credits associated with insulation. As we’ve mentioned in this space, R-value is also key in determining whether or not your insulation is qualified for CPS San Antonio’s sizable insulation rebates as well.