How Insulation R-Values Impact Efficiency

October 06, 2011

In the varied climate of Johnson County, with weather highs and lows, adding insulation to your home can provide year-round benefits and savings. To get the most of your insulating efforts, however, you must understand insulation types and R-values.

R-value is a measurement of the insulation's resistance to heat flow. The higher the R-value, the higher that resistance is -- meaning the greater the effectiveness of the insulation. Basically, higher is better; however, there are other factors to consider:

  • Type of insulation - Not all type of insulation are suitable for all purposes.
  • Installation - Improper installation, such as compressing insulation to make it fit, will alter R-values.
  • Need versus cost - You don't need the very highest R-value for every purpose, such as covering ductwork. The goal is to save money, not go broke buying insulation!

R-value is often measured in inches. The commonly encountered fiberglass blanket insulation, for example, typically has an R-value range of 2.9-4.3 per inch of thickness. Adding more inches -- layers -- adds more R-value.

Most homes will get the most benefit from adding attic insulation. If your attic's insulation is level with or below attic floor joists, you'll probably benefit from adding more. The U.S. Department of Energy recommends an R-value of 38 or higher in most attics. Many homes have poorly insulated basements or crawlspaces as well.

Insulating ductwork and water pipes will also boost your energy efficiency, as well as help prevent condensation and inhibit mold growth. Foam insulation is available to fit most ductwork and pipes. Look for an R-value of 3 or higher.

The Federal Trade Commission requires all insulation be clearly labeled with R-value and other key information, including any health, safety or fire-hazard issues -- all of which are important to take into account when selecting insulation.

Likewise it's important to note that the more you seal and insulate your home, the more you need to pay attention to your ventilation systems, or your indoor air quality may suffer.

If you still have questions about R-values or increasing your home's efficiency with insulation, you're welcome to contact us at Santa Fe Air Conditioning & Heating. We'll be happy to discuss your home's unique insulation needs.