A measure of thermal resistance used to compare insulating values The higher the R-value number of a material, the better its insulating properties and the slower the heat flows through it Optimum Utility Systems provides evaluations of roof, wall, floor, piping, and equipment insulation at manufacturing and processing sites and recommends cost-effective improvements See related article
Measure of resistance to heat flow The R-value is the reciprocal of the amount of heat energy per area of material per degree difference between the outside and inside Insulation for the home has R-values usually in the range of R-10 up to R-30 The R-value is proportional to the thickness of the material For example, if you doubled the thickness, the R-value doubles The following table lists R-values for commonly-used construction materials at one-inch thickness: Material R-value Hardwood siding 0 91 Brick 1 00 Poured Concrete 0 08 EPS (1 5 lb density) 4 EPS (2 0 lb density) 4 2 Fiberglass batting 3 11 Cellulose fiber 3 70 Drywall 0 90
A measure of a substance's resistance to heat flow The R-values of materials are added to produce the total R-value of a building surface The higher the R-value, the greater the resistance to heat flow
refers to insulation's resistance to heat flow, not to its thickness Tiny air pockets trapped in the insulating material resist the passage of heat preventing heat gain in the warm summer months, and heat loss in the colder fall and winter seasons The higher the insulation's R-Value, the greater its insulating power
The measure of a materials resistance to heat flow The higher a materials R-value, the more it insulates For more information on R-Value, click on the term
A unit of thermal resistance used for comparing insulating properties of different materials The higher the R-value, the greater the material's insulating abilities Applies to roofing, insulation, windows etc
Resistance to heat flow, a high R-value indicates that a window has good heat-insulating properties, whereas a low R-value indicates that a window has less heat-insulating value For more, see our HomeTips article, Understanding U-Factors & R-Values
A measure of the ability of a material to insulate against heat loss The higher the R-value, the better the material is at insulating R-values are usually expressed in terms of a standard unit of thickness of the material For example, loose fiberglass insulation has an average R-value of 2 7 per inch, while rigid boards made of expanded polystyrene insulation have an R-value of 4 per inch
R-value is a measurement of heat resistance It is the inverse of the U-value, so the higher the R-value the better the insulation resists heat transfer Many factors can affect the R-value of insulation, including the type of insulation, and the age of the insulation To determine the R-value of the insulation in your house, first determine the type of insulation present, whether that insulation is new, and measure the depth of the insulation in inches Look your insulation up on the table below, and multiply the R-value per inch by the number of inches present in your house
A measure of a material's resistance to the flow of heat R-value is a laboratory measurement based on the constant temperatures on both sides of a material However, it does not reflect the fluctuating conditions that face the insulating materials in actual use, nor does it include the effect of thermal mass on energy efficiency
quantitative measure of resistance to heat flow or conductivity, the reciprocal of U-factor The units for R-value are ft2 °F hr/Btu (English) or m2 °K hr/W (SI or metric) While many in the building community consider R-value to be the primary or paramount indicator of energy efficiency, it only deals conduction, one of three modes of heat flow, (the other two being convection and radiation) As an example of the context in to which R-value should be placed, 25% to 40% of a typical home's energy use can be attributed to air infiltration
A unit of thermal resistance used for comparing insulating values of different material It is basically a measure of the effectiveness of insulation in stopping heat flow It is a measure of a material's resistance to heat flow in units of Fahrenheit degrees x hours x square feet per Btu The higher the R-value of a material, the greater its insulating capability
a measure of the rate of resistance to heat loss or gain through a material; typically a wall or a roof The higher the R-value, the greater the material's resistance to heat flow and the better its insulating value
A unit of thermal resistance used for comparing insulating values of different materials The higher the R-Value of a material, the greater its insulating properties and the slower the heat flows through it
R-value is a measure of how well insulation will resist the flow of heat Higher R-values mean greater insulating ability, which means greater household energy savings and greater cost savings
A measure of the resistance of a glazing material or fenestration assembly to heat flow It is the inverse of the U-factor (R = 1/U) and is expressed in units of hr-sq ft-°F/Btu A high-R-value window has a greater resistance to heat flow and a higher insulating value than one with a low R-value