What does R-Value Mean?

An important rating system for insulation shoppers

What is R-Value?

If you have been considering insulation for your home or commercial space, you have probably come across the term “R-value.” R-value can have a huge impact on the efficiency of your home systems and future utility costs. But what is an R-value of insulation?

Simply put, R-value is a measure of thermal resistance used to categorize insulation types. The higher the R-value (or “resistance value”), the greater the insulating effectiveness. R-value is used to measure the resistance of heat flowing through a specific material based on its thickness. When you see a high R-value, it means that this insulation is more resistant to heat flow.

Why is R-Value Important for Insulation?

Insulation is designed to stop the flow of heat out of your home and keep the interior of your home warm in the winter months. R-value can also greatly affect the bottom line of business expenses if you select commercial building insulation that isn’t a good fit for your needs.

In many cases, consumers think that R-value is the only thing that determines the quality of the insulation. However, there are four factors that go into determining the effectiveness of insulation for your home. The four factors are conduction, convection, air infiltration, and radiation. R-value measures three of these four factors.

Although some people suggest that R-value only measures the conductive heat flow of a material, it also measures radiation and convection heat flow as well. The testing used to determine the R-value of a material is called AST C518, which is short for the Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus. Since R-value measures all three types of heat flow, it is an effective way to determine the insulation properties of materials.

Proper insulation can save you money on your annual cooling costs. In some cases, insulation installation is eligible for a federal tax credit. Since each insulation has a different R-value, it’s important to research which ones work best for each installation project.

What is the Best R-Value of Insulation in Your Home?

When it is time to pick insulation for your home, there are a few things that you need to consider. The first is where you live. If you live in an area with a cold climate, then you will want insulation with a higher R-value. Insulation panels with the highest R-values, like vacuum insulated panels, can have ratings of up to R-45 per inch. On the other hand, some foam insulations have a rating of R-7 per inch, which is better suited to more temperate climates. Lower R-rated insulation can also save you money in terms of material costs if you don’t need heavy-duty cold weather insulation. For R-value information based on your climate zone, reference the map below.

Climate Map for R-Value

Next, consider the specific features of your home. Is your home a multi-level or single-level structure? Do you have cathedral ceilings? These factors and others play a role in determining the type of insulation that you need. Additionally, consider your cooling and heating systems. Heat pumps, furnaces, and central air conditioners make a difference in the type of insulation that you should install.

Practical Considerations for R-Value Ratings

The measurement of the R-value of insulation is measured in a lab. However, you are not using your insulation in a lab setting. Each day, your home is affected by circumstances like humidity, wind, and temperature changes. These factors change the pressure difference between the interior and exterior walls of your home. Pressure differences can also be the result of rising hot air and forced air from various mechanical systems in your home.

These pressure differences allow heated air to move into areas in your home that are unheated such as your attic, basement or garage. Inside the building materials used to construct your home, there can be small gaps and fissures that your heated air can be forced through when there is a pressure difference between your interior and exterior walls.

For the best insulation possible, you will want to choose a product that has a high R-value. Ensure the space is fully filled with insulation. This will avoid heat loss through convection. Your insulation must be densely packed to keep from losing heat through radiation and air infiltration. If you get the right balance of these four factors in your home insulation, you will find that your energy bills will be lower, and your home will be more energy efficient during the winter months.

Insulation Installation Near You

Whether you need residential or commercial building insulation, TruTeam is here to help. For more information on R-values necessary in your home or business or for a free quote on your insulation project, contact our local experts. Our insulation specialists can help with every step of the insulation process, from material selection to completed installation. We are the leading installer of insulation in the United States, and we are available to answer any questions you have about insulation.

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