a measure of the resistance of a material or assembly to heat flow. It is the inverse of the U-factor (R = 1/U) and is expressed in units of hr-ft2-[ring]F/Btu. The higher a window's R-value, the greater are its resistance to heat flow and its insulating value.

The measure of a material’s resistance to heat flow. The higher a material’s R-value, the more it insulates. For more information on R-Value, click on the term.

A value given for the resistance to heat transfer of a roof or wall system.

The measure of a material's insulating ability or resistance to heat flow. The higher the R-value of a material or assembly, the higher the insulating value.

The resistance of a material to heat flow is its R-value. The higher the R-value the better the material insulates against heat transfer. R-value can be compared to the U-value by dividing 1 by the U-value. (R=1/U)

A measure of the ability of a substance or combination of substances to retard the flow of heat. The higher the R-value, the better the insulating properties of the substance.

The resistance a material has to heat flow. Higher numbers indicate greater insulating capabilities.

The measurement of how insulation can slow down the transfer of hot and cold temperatures; the higher the R-value the better the insulation

A measure of a product's energy efficiency. Resistance to heat transfer. The higher the R-value, the better the insulating effect & the lower the rate of heat flow.

(Thermal Resistance) A measure of resistance to heat flow of a material or construction a higher value indicates a better heat insulating property. The R-value of an ordinary single-pane sash with a 15 mph wind on one side is about 0.9.

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) EPS (2.0 lb density) 4.2 Fiberglass batting 3.11 Cellulose fiber 3.70 Drywall 0.90

The measurement of thermal resistance to heat flow. A higher R-value indicates greater insulating effectiveness. The type of material, its density and its thickness are all factors in determining R-value. Installing more insulation in a building helps the R-value increase.[xvi

Measure of the resistance of a material to heat flow. The higher the number, the greater the resistance to heat flow.

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.

R-value is a measure of the thermal resistance of a material. Thermal resistance is an index of a materials' resistance to the flow of heat. It is the reciprocal of the thermal conductivity.

The plastic strain ratio is a measurement for the resistance to thinning during forming operations: the ratio of true width strain divided by true thickness strain in the uniform elongation region of a tensile test.

A WHOLE OR MIXED NUMBER THAT IDENTIFIES A WINDOW, DOOR , SKYLIGHT OR WALL'S ABILITY TO RESIST THE FLOW OF HEAT THROUGH IT. THE HIGHER THE NUMBER, THE BETTER (EXAMPLE: AN R=2.7 IS BETTER THAN AN R=2.0). R IS EXPRESSED IN UNITS OF HOUR PER SQUARE FEET IN DEGREES FAHRENHEIT OF BRITISH THERMAL UNIT. PROFESSIONALLY, FENESTRATION ORIENTED ORGANIZATIONS USE "U"-VALUE, WHICH THE INVERSE OF "R".

Grading standard for insulating materials. It stands for "resistance to heat flow" and is stamped on most good brands of insulation material. The higher the R factor the better.

a measure of resistance to heat flow through a unit width of material expressed in moC/W (hr.ft2.oF/BTU.in).

ability of a material to resist heat flow; the higher the R-value, the more powerful the insulation.

A measure of thermal resistance, indicating how effective a material is as an insulator. R-value is measured in the hours needed for one Btu to flow through one inch of the material when the temperature difference (from one side of the material to the other) is one degree Fahrenheit. Its units are hour-square foot-degree Fahrenheit/Btu-inch.

a measurement of how much heat insulation allows to pass through its insulating barrier

a measurement of the resistance to heat transfer

a measure of an insulation 's resistance to heat flow

a unit of thermal resistance used for comparing insulating properties of different materials

A measure of a material's ability to resist the flow of heat. The formula for an R-Value is R=1/. This value is expressed as BTU/h/square ft.

The measurement of resistance to heat transfer in a material. The higher the R-Value, the greater the insulation value.

A measurement of the insulative ability of a material.

A measurement 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.

A measure of thermal resistance. The R-value gauges the effectiveness of different types of home insulation; the greater the R-value, the greater the level of insulation quality.

The measure of a material’s resistance to heat flow. The higher a material’s R-value, the better it’s insulating properties.

A measure of the resistance an insulating material offers to heat transfer. The higher the R-value, the more effective the insulation.

A unit of thermal resistance. A material's R-value is a measure of the effectiveness of the material in stopping the flow of heat through it. The higher a material's R-value, the greater its insulating properties and the slower the heat flow through it.

A measure of resistance to the flow of heat. Higher R-values indicate a material's greater ability to insulate. The energy efficiency of log homes is not measured in R-value.

The ability of insulation to slow heat loss is measured by R-value, or heat-flow resistance factor. The more effective the insulation, the higher its R-value.

R-value is a measure of a material's or a construction's ability to retard heat flow. It is convenient to use because R-values of materials in series can be added to determine a construction's total thermal resistance. [R = 1/K -or- 1/C] The higher the R-value, the better the resistance to the flow of heat (BTUs) and the better the insulation. R-values are usually reported for 1-inch of thickness. R-values are usually reported at mean temperatures of 75°F (24°C).

Refers to a window's resistance to thermal transfer or heat flow. The higher the value, the better the insulation.

Unit of measure describing the ability of an insulation to resist heat flow. Higher values permit less heat flow.

The thermal resistance of a glazing system. The higher the R-value the less heat is transmitted throughout the glazing material. The R-value is the reciprocal of the U-value.

A measure (h ft2 °F/Btu) of thermal resistance, or how well a material or series of materials resists the flow of heat. The R-value is the reciprocal of the U-factor.

Numeric meaurement of a material's resistance to thermal transfer. The measurement represents the time it takes for one degree Fahrenheit of heat to transfer through the material. The larger the number the better the insulation provided by the material.

The resistance of conductive heat energy. The higher the number the greater the insulating capacity. It is the reciprocal of a U-value; R=1/U.

A measure of the resistance of a material or assembly to heat flow. It is the inverse of the U-factor (R = 1/U) and is expressed in units of hr-ft 2 -°F/Btu. A high window R-value, has a greater resistance to heat flow and a higher insulating value.

Represents a material's ability to resist heat loss. A high R-value indicates the ability of the material, such as insulation, to retain heat in the winter, and the ability to resist heat in the summer. For Oregon, the Revised Energy Code calls for walls to be rated R-21, floors R-25, flat ceilings R-38, and vaulted ceilings R-30. Radiant Energy Energy contained in light rays, which may be absorbed by a man-made solar energy collector, such as solar panels, and dispersed as heat.

A measurement of how much a material resists heat transfer. A higher R-Value means a greater insulating effect and a lower rate of heat flow.

The resistance of a material to heat flow. This common measurement is the reciprocal of the U-Value. R-Value can be compared to U-Value by dividing 1 by the R-Value. (Thus, an R-Value of 2 equals a U-Value of 0.5.) See U-VALUE.

An expression of the insulating properties of a material as measured by resistance to the flow of energy from inside a house to the outside. Higher numbers indicate better insulation.

Resistance to thermal transfer or heat flow. Higher R-value numbers indicate greater insulating value.

The measurement of a materials resistance to heat flow. salvage The recovery (monetary) value of a damaged component or item.

A measure of the resistance of a glazing material or fenestration assembly to heat flow.

The thermal resistance of a glazing system. The R-value is the reciprocal of the U-value. The higher the R value, the less heat is transmitted throughout the glazing material.

The Resistance to heat transfer of a material. Insulators have relatively high R values.

The R-value of a window refers to the amount of heat loss it allows. The higher the number, the less heat is lost. R-values today can go from 0.9 to 4.0, or even more.

A number assigned to thermal insulation to measure the insulation's resistance to heat flow. The higher the number, the better the insulation.

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 measure of the thermal resistance of a building element; the reciprocal of the U-value. See thermal resistance.

The resistance to heat flow. This unit characterizes the insulating value of materials that are used to minimize heat flow. Higher R-values indicate a material's ability to resist more heat flow.

A term which, when used with a number, indicates the level of resistance to heat flow in a building material. The higher a material's R-value, the more effective insulation it provides.

In thermal insulation, the thermal resistance of insulation materials or constructions.

A construction term that refers to the resistance of to heat loss. The higher the R-value, the slower the rate of heat loss.

Measure of thermal resistance used in housing insulation.

Thermal resistance, a measure of a material's or a construction's ability to retard heat flow. R-Values in a series of materials can be added to determine a construction's total thermal resistance.

A measurement that indicates the ability of a material to resist heat transfer. The higher the R-Value of a material, the greater its insulating properties.

The resistance of insulation material (including windows) to heat passing through it. The higher the number, the greater the insulating value.

The rating of a window treatment in its capacity to resist the flow of incoming or outgoing heat.

marks a window's resistance to heat loss or gain. The higher the R-value, the better the window reduces heating and cooling bills.

R-value measures insulation's resistance to heat flow; it is important for temperature control issues.

Measure of resistance to heat flow. The higher the R-Value, the more insulation provided.

Resistance a material has to heat flow. The higher the R-value, the greater the resistance.

Measures the insulation effectiveness of the window. The R-value equals one divided by the U-value. The higher the R-value, the better insulating performance.

R-value measures the resistance of a glazing material or fenestration assembly to heat flow. It is the inverse of the U-factor. A high R-value window has a greater resistance to heat flow and a higher insulating value than one with a low R-value.

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. The higher the R-value number, a material, the greater its insulating properties and the slower the heat flow through it. The specific value needed to insulate a home depends on climate, type of heating system and other factors.

A unit of thermal resistance, the opposite of thermal conductance. The higher the R value, the greater the insulating quality.

The number of minutes (seconds) required for 1 Btu (joule) to penetrate one square foot (square meter) of a material for each degree of temperature difference between the two sides of the material. The resistance of a material to the passage of heat. The reciprocal of conduction (1/c).

The measure of resistance to heat flow. Insulation materials have tiny pockets of trapped air. These pockets resist the transfer of heat through material. The ability of insulation to slow the transfer of heat is measured in R-values. The higher the R-value, the better the insulation material's ability to resist the flow of heat through it. The Federal Trade Commission prohibits expressing R-value in terms of inches, because R-value is not a linear measurement.

You want to look for higher R values. The R-value measures the resistance of thermal transfer or heat flow through the window. A typical R-value for the center of a double glazed window is R2. When Low-E and argon gas are added, the R-value typically doubles to about 4, reducing heat loss by approximately 50%.

This refers to the resistance a window has to thermal transfer or heat flow. The higher the value, the better the insulation.

Thermal resistance is expressed in ft^2/hr/°F/BTU. It is the reciprocal of U-value. The higher the R-value, the less heat is transmitted through the glazing material.

A measurement of the ability of insulation to slow the transfer of heat or cold. The higher the R­value, the greater the insulation power.

The thermal resistance of glazing or insulation. The higher the R value, the less heat is transmitted throughout the material.

A number which describes in relative terms, the ability of a material or assembly to resist the flow or transmittance of heat. Assemblies or materials with high R-values are better insulators than those with lower R-values.

resistance value, used specifically for materials used for insulating structures. Three inches of fiberglass insulation has an R-value of 11.

A measure of thermal resistance of a material, equal to the reciprocal of the U-Value. The R-Value is expressed in terms of degrees Fahrenheit times hours, times square feet per Btu.

R-Value refers to a window treatment, ceiling, or wall's capacity to keep heat in or out.

R-value is a term used indicate an objects ability to resist heat loss. The higher the R-value, the better an objects ability to resist heat loss. R-values are determined by inverting the U-value (R=1/U).

A measure of insulation. A measure of a materials resistance to the passage of heat. The higher the R value, the more insulating "power" it has. For example, typical new home's walls are usually insulated with 4" of batt insulation with an R value of R-13, and a ceiling insulation of R-30.

With regard to insulation; an "R" value measures the insulation material's resistance to heat. A higher "R" value means greater insulation. If the inside of an exterior wall is about the same temperature as other interior walls, then the insulation is deemed adequate.

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.

A measure of a material's resistance to heat loss, usually applied to insulation products. The higher the R-value, the slower the rate of heat loss.

The R-value is a measure of thermal resistance. The SI units for thermal resistance are K·m²/W. R-values are commonly used to characterize thermal insulation materials in buildings.

The R-Value test, http://www.dot.ca.gov/hq/esc/ctms/CT_301.pdf California Test 301, measures the response of a compacted sample of soil or aggregate to a vertically applied pressure under specific conditions. This test is used by CalTrans for pavement design, replacing the California Bearing Ratio test. Many other agencies have adopted the California pavement design method, and specify R-Value testing for subgrade soils and road aggregates.