Definitions for

**"Thermal conductivity"****Related Terms:**Thermal conductance, Thermal coefficient of expansion, Heat capacity, Heat transfer coefficient, Specific heat, Thermal resistance, Conductance, Specific heat capacity, Btu, Cte, U-factor, British thermal unit, Heat flow, K-factor, B.t.u, Coefficient of thermal expansion, U-value, Thermal capacity, Btuh, Btu/h, Thermal, Coefficient of expansion, Thermal insulation, Thermal inertia, Heat load, Heat content, Boiler horsepower, Enthalpy, Pyrometer, Thermometer, U value, Heat flux, Ptc, Temperature, Positive temperature coefficient, Differential scanning calorimetry, R-value, Kelvin, Temperature rise, Thermal efficiency, Sensible heat, Conduction, Hspf, Heat rise, Latent heat of vaporization, Thermal expansion, Negative temperature coefficient, Dsc, Total heat

The property of a material that describes how well heat passes through it.

The thermal conductivity of a substance is the quantity of heat in cal/sec passing through a body 1 cm thick with a cross section of 1 sq. cm when the temperature difference between the hot and cold sides of the body is 1 deg. C.

The rate at which heat is conducted through a solid at 'steady state' (meaning that the temperature profile does not change with time) is governed by the thermal conductivity. It is measured by recording the heat flux J (W/mÂ²) flowing from surface at temperature T1 to one at T2 in the material, separated by a distance X.

The relative ability of a material to conduct heat.

This property is known as the K factor. It is a measure of the transfer of heat by conduction. It tells how much heat is transferred from one side of a plate to the other side. It is measured as BTUs (units of heat in the English system) per hour per unit area (square feet) for a thickness of one inch and a temperature difference of one degree Fahrenheit between both sides of the plate. Units - BTU/hr/sq/°F/inch. - Watt/(Meter Deg Kelven) W/MK. Higher numbers mean that the material will absorb more energy before it is broken by a moving weight.

The ability of a material or substance to transmit or diffuse heat

Rate at which heat will flow through a material.

The heat energy that will be transmitted by conduction through 1 square foot of 1inch thick homogeneous material in 1 hour when there is a difference of 1 degree Fahrenheit perpendicularly across the two surfaces of the material. The higher the k-value, the lower the R-value. Materials with high k-values are good heat conductors, and conversely. For more information, click here.

The property of matter by which heat energy is transmitted. For engineering purposes it is measured by the amount of heat transmitted by a given section over a given length under a known temperature difference in a unit of time, ic., CaIlcm2/cmICIsCc.

Measures the transfer of heat through a material.

Heat transfer property of materials expressed in units of 'Btu (Btuh) per hour per inch of thickness per square foot of surface per one degree F. temperature difference.' Referred to by the letter 'k.'

an intrinsic property of a material indicating how well heat transfers through the material.

Thermal conductivity () is rate of heat flow divided by area and by temperature gradient.

property of a material indicating its ability to transfer heat

Measures the rate at which heat is transferred.

Property of a material which describes its ability to conduct heat.

See CONDUCTIVITY, THERMAL.

Thermal conductivity is a physical property of a material that characterizes the ability of that substance to transfer heat. The value of thermal conductivity determines the quantity of heat passing per unit of time per unit area at a temperature drop of 1-degree C per unit length. In the limit of infinitesimal thickness and difference in temperature, the fundamental law of heat conduction is: Where: is a measure of the heat flow is the cross sectional area is the temperature / thickness gradient is defined as the thermal conductivity Thermal conductivity differs with each substance and may depend on the structure, density, humidity, pressure and temperature. Materials having a large thermal conductivity value are good conductors of heat; one with a small thermal conductivity value is a poor heat conductor i.e. good insulator. Hence, knowledge of the thermal conductivity value (units W/m•K) allows for quantitative comparisons to be made between the thermal insulation efficiencies of different materials.

The property of a material that describes the rate at which heat will be conducted through a unit area of the material for a given period of time.

The measure of heat transmission through a cellular material. Determined by the base material, cell size, density and often water resistant properties.

The ability of a material to transmit heat through its bulk and, by direct contact, to other substances. Aluminum is a good heat conductor and is widely used in cookware and in radiators and other heat exchangers.

A unit for comparing or calculating quantities of heat. Thermal Conductivity is the amount of heat necessary to raise the temperature of one gram or one pound of water from zero to one degree Centigrade.

A measure of how rapidly heat travels through an object.

Thermal conductivity of a rock is the measure of how easily heat is transmitted through the rock. It is power per unit distance per unit temperature and is measured in units of W/m/K.

It is the rate of heat flow, under steady conditions, through unit area, per unit temperature gradient in the direction perpendicular to the area. Thermal Conductivity is usually expressed in English units as BTU's per square foot per hour per degree Fahrenheit for a thickness of one inch. (ASTM C518)

The rate of heat flow under steady state conditions through unit area per unit temperature gradient in a direction perpendicular to an isothermal surface.

The ability of a substance to transmit heat through its molecules.

The measure of the rate at which heat passes through a material, expressed in W m-1 K-1

property of a substance which measures its efficiency to conduct heat

The ability of a material to conduct heat. Diamonds have the highest conductivity of any material.

A measure of the rate of flow of thermal energy through a material in the presence of a temperature gradient. Materials with high electrical conductivities tend to have high thermal conductivities.

The degree to which a material acts as a conductor or heat sink.

The time rate of heat flow through unit thickness of a flat slab of a homogenous material in the perpendicular direction to the slab surfaces induced by unit temperature gradient. Units for k are (Btu in) / (hour ft2 ¡F) or Btu / (hour ft ¡F) [Imperial system] and Watts / (m ¡C) [SI system]. See "Thermal resistivity".

The quantity of heat that will flow through a unit area of a substance in unit time under a unit temperature gradient. In permafrost investigations thermal conductivity is usually expressed in W m-1 oC-1

The rate of heat flow, in BTU's per hour, through a square foot of material exactly one inch thick whose surfaces have a temperature differential of 1 F.

A measure of the capacity of a material to conduct heat.

The measurement of heat transmitted through a material. A low k factor indicates that the material is a good thermal insulator. Units of k are Btu-in./hr-ft2-Â°F or, in SI, W/m Â°C.

A measure of a rock's capacity for heat conduction.

A measure of a plasticâ€(tm)s ability to conduct heat.

The property of a material to conduct heat in the form of thermal energy.

The measure of the rate at which heat passes through a material, expressed in cal . cm-1 . sec-1 . °C-1. The symbol is K.

(1) The heat energy that will be transmitted by conduction through one square foot of 1" thick homogeneous material in one hour when there is a difference of 1? F perpendicularly across the two surfaces of the material. The formula for thermal conductivity is: k = Btu/SQUARE FOOT/ INCH/HOUR/DEGREE FAHRENHEIT. (2) Heat energy (Btuh) transferred via conductance only through a 1-in.-thick 1 ft2 area of homogeneous material per ?F temperature difference from surface to surface. Unit for k is Btuh/(in.2?F).

It is defined as the rate of flow of heat between two surfaces of unit area sepated by unit distance when the temperature difference between them is 10 C.

Ability of a material to conduct heat; physical constant for quantity of heat that passes through a unit cube of a substance in a unit of time when difference in temperature of two faces is 1 degree.

A measure of the rate at which a material conducts heat through its thickness.

the ability of a material to conduct heat; physical constant for quantity of heat that passes through volume of a substance in unit of time for unit difference in temperature.

This is a factor used to express the ability of the body to transfer heat by conduction. Units are Btu's/(ft×hr×°F)

measure of the ability of a solid or liquid to transfer heat.

the heat energy that will be transmitted by conduction through one square foot of one inch thick homogeneous material in one hour when there is a difference of one degree Fahrenheit perpendicularly across the two surfaces of the material.

A property of materials which measures the ability of a material to conduct heat. It can be expressed as power per degree length (watts/meter-C). Metals have a high thermal conductivity (conduct well) while air fibers and plastics have much poorer conductivities.

A measure of how rapidly heat is conducted through a material.

The ability of a substance to conduct heat. Mathematically, the ratio of the rate of heat flow to the rate of temperature change in the particular substance.

The property of matter by which heat energy is transmitted through particles in contact. For engineering purposes, the amount of heat conducted through refractories is usually given in Btu per hour for one square foot of area, for a temperature difference of one degree Fahrenheit, and for a thickness of one inch, Btu/hr·ft·F/in.

A measure of a materials ability to move heat from one place to another. During laser cutting, the cut zone should be heated without wasting energy heating up surrounding workpiece material. Materials with high thermal conductivity, such as copper and aluminum, cutting is slowed down as heat escapes from the cut zone.

The ability of a material to conduct heat, expressed as thermal power conducted per unit temperature and thickness. Metals and other thermal "conductors" have a large thermal conductivity. Refractories and other thermal "insulators" have a low thermal conductivity.

A measure of a material's ability to conduct heat. Measured in BTU-inch/hours-square foot/°F or calorie-centimeters/second-square centimeters/°C.

In physics, thermal conductivity, k, is the intensive property of a material that indicates its ability to conduct heat.