Achieving Greater R-Values in Exterior Walls As with attics or anywhere else in your home, adding more layers of insulation to your exterior walls is key to having a higher R-value and better thermal performance. Foam board insulation is easy to install between wall studs and over existing blanket insulation.
Installing more insulation in your home increases the R-value and the resistance to heat flow. In general, increased insulation thickness will proportionally increase the R-value.
Vacuum insulated panels have the highest R-value, approximately R-45 (in U.S. units) per inch; aerogel has the next highest R-value (about R-10 to R-30 per inch), followed by polyurethane (PUR) and phenolic foam insulations with R-7 per inch.
R-Value is a measure of insulation's ability to resist heat traveling through it. The higher the R-Value the better the thermal performance of the insulation.
R-Value 2.0 to 3.5 – Cool
An R-Value of 2.0 to 3.5 will be sufficient to keep you warm in temperatures as low as 5º.
Fiberglass and rock wool batts—2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products. Generally, batt insulation is the least expensive wall insulation material but requires careful installation for effective performance (see page 4).
In finance, an R-squared above 0.7 would generally be seen as showing a high level of correlation, whereas a measure below 0.4 would show a low correlation. This is not a hard rule, however, and will depend on the specific analysis.
Insulation ratings can be improved by adding more layers of insulation. You can mix the type and material of insulation too. For example, if your attic already has fiberglass insulation blankets installed, you can improve its R-value by installing blown-in cellulose insulation on top of the blankets.
It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.
Simply put, R Value is a term the construction industry uses to explain how well a material prevents heat from passing through a given material. The higher the R Value, the greater the resistance and better thermal insulating power.
A higher R-value means a higher insulating rating. In other words, the higher the R-Value, the better the product is at insulating your home. This means less heat loss in winter, less heat gain in summer and increased savings on your energy bill year round.
The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space. While you might think that too much insulation can't be bad, there are some significant consequences to consider.
Depending on where you live and the part of your home you're insulating (walls, crawlspace, attic, etc.), you'll need a different R-Value. Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces.
We've learned that R-values are a measure of thermal resistance, indicating how well a material can resist heat flow. The calculation of R-values involves several factors, including material type, thickness, density, temperature, and the age and condition of the insulation.
Compression. Improperly installed insulation loses its R-value. For example, fiberglass can lose up to 50 percent of its prescribed R-value when compressed.
Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests. However, if the insulation is in decent shape and just needs a boost, adding a new layer on top can be a cost-effective option.
As a general guideline, it's advisable to install double layers of thermal insulation throughout your house. Nevertheless, this may not be feasible in all areas due to space limitations. Typically, it's not practical to add two layers of insulation within the walls of your home.
Never place insulation close to water heaters, oil burners or anything hot. The backing is especially flammable and will be a major fire hazard for your home.
The thermal barrier of a home should consist of a continuous layer of insulation on all sides—including the lowest floor, the exterior walls, and the ceiling or roof. Doubling the thickness of insulation will double the insulation's R-value, cutting heat loss in half.
Thermablok® Aerogel is a revolutionary advancement in thermal technology offering the thinnest insulation available to prevent thermal and cold bridging. Classed as a Super Insulation, Aerogel has the highest insulation value of any known material with the lowest thermal conductivity value of any solid (0.015W/mK).
Spray foam insulation offers better longevity because it can be used with traditional construction methods such as bricks and blocks, which are more durable than SIPs. Spray foam is an alternative that allows you to have the best of both worlds.
If we wish to label the strength of the association, for absolute values of r, 0-0.19 is regarded as very weak, 0.2-0.39 as weak, 0.40-0.59 as moderate, 0.6-0.79 as strong and 0.8-1 as very strong correlation, but these are rather arbitrary limits, and the context of the results should be considered.
The R-value (the 'R' stands for “resistance”) will tell you how well different barriers will resist that transfer. In the US, you will see R-values ranging from 0 to 66. Higher numbers mean better resistance to heat transfer.