#### Heat Transfer Knowledge and Engineering

The following are links to heat transfer related resources, equations, calculators, design data and application.

Heat transfer is a study and application of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy and heat between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes.

Heat Transfer Equations and Calculators
Hemispherical Emissivities of Various Surfaces Table - emissivities of various surfaces at several wavelengths and temperatures.
Heat Loss Through Enclosure Walls Equations and Calculator Determine required wall thickness of an enclosure for temperature control and insulation requirements. Known Design Data: Size (thickness) of insulated encluosure walls and inside and external surface temperatures
Heat Loss Through a Wall Equation and Calculator Determine the steady state heat loss through a single wall.
Heat Loss through Aluminum Framed Window Equations and Calculator Design equations and calculator example Heat Loss through Aluminum Framed Window.
Heat Loss through a Single-Pane Window Equation and Calculator

Assumptions

1 Heat transfer through the window is steady since the surface temperatures remain constant at the specified values.
2 Heat transfer through the wall is one-dimensional since any significant temperature gradients will exist in the direction from the indoors to the outdoors.
3 Thermal conductivity is constant.

Heat Loss through a Double-Pane Window Equation and Calculator A double-pane window is considered. The rate of heat transfer
through the window and the inner surface temperature are to be determined.
Conduction-Rectangular Coordinates Calculation Example Conduction - Rectangular Coordinates example calculation
Conductive Heat Transfer Parallel Cylinders Equation and Calculator Conductive Heat Transfer of A row of equally spaced parallel isothermal cylinders buried in a semi-infinite medium (L >>D, z and w >1.5D)
Conductive Heat Transfer Cylinder of Length Equation and Calculator Conductive Heat Transfer of Circular isothermal cylinder of length L in the midplane of an infinite wall (z > 0.5D)
Conductive Heat Transfer Square Solid Equation and Calculator Conductive Heat Transfer of Circular isothermal cylinder of length L at the center of a square solid bar of the same length
Conductive Heat Transfer Eccentric Cylinder Equation and Calculator Conductive Heat Transfer of Eccentric circular isothermal cylinder of length L in a cylinder of the same length (L > D2).
Conductive Heat Transfer Large Plane Equation and Calculator Conductive Heat Transfer of Large plane wall equation and calculator.
Conductive Heat Transfer of a Cylindrical Pipe or Layer Equation and Calculator Q = Rate of Steady State Heat Conductivity (W)
S = Conduction Shape Factor (ft) which has the dimension of length, and k is the thermal conductivity of the medium between the surfaces. The conduction shape factor depends on the geometry of the system only.
Conductive Heat Transfer of a Isothermal sphere buried in a semi-infinite medium Conductive Heat Transfer of a Isothermal sphere buried in a semi-infinite medium at T2 whose surface is insulated
Conductive Heat Transfer of a Spherical Layer Equation and Calculator Conductive Heat Transfer of a spherical layer equation and calculator
Conductive Heat Transfer of a Disk buried parallel to the surface Conductive Heat Transfer of a Disk buried parallel to the surface in a semi-infinite medium (z >> D)
Conductive Heat Transfer of the edge of two adjoining walls of equal thickness Conductive Heat Transfer of the edge of two adjoining walls of equal thickness
Conductive Heat Transfer Corner of three walls equal thickness equation and calculator Conductive Heat Transfer of a Corner of three walls of equal thickness equation and calculator
Conductive Heat Transfer Isothermal sphere buried medium equation and calculator Conductive Heat Transfer of a Isothermal sphere buried in a semi-infinite medium equation and calculator
Steady State Conduction Multi layer Cylinder Calculation Equation and calculator temperature on one side of an isothermal constant temperature multilayer cylinder.
Heat Loss From an Insulated Electric Wire Equation and Calculator Heat transfer is steady since there is no indication of any change with time
Maximum Power Dissipation of a Transistor Equation and Calculator

Assumptions:

2 The transistor case is isothermal at 85°C.

Heat Loss of Two Cylinders at Known Separation Equation Steady State Rate of Heat Loss of Two Cylinders at Known Separation Equation and Calculator. Two parallel isothermal cylinders placed in an infinite medium (L >>D 1 , D 2 , z)
Isothermal cylinder of length L buried in a semi-infinite medium calculator Steady State Rate of Heat Loss of Isothermal Cylinder. Isothermal cylinder of length L buried in a semi-infinite medium (L >>D and z >1.5D)
Heat Loss of cylinder buried in medium equation and calculator. Heat Loss of cylinder buried in a semi-infinite medium equation and calculator. Vertical isothermal cylinder of length L buried in a semi-infinite medium (L >>D)
Linear Thermal Expansion Equation and Calculator Linear expansion is the change in length as opposed to change in volume. To a first approximation, the change in length measurements of an object due to thermal expansion is related to temperature change by a "linear expansion coefficient".
Extruded ( Finned )Heat Sink Radiation Formulae Equation to calculate the radiation from an extruded (finned) heat sink.
Selecting a Heat Sink for a Transistor Equation and Calculator

Assumptions:

2 The transistor case is isothermal at 90°C.
3 The contact resistance between the transistor and the heat sink is negligible.

Convection of Known Surface Area Calculator Convection of mass cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids.
Convective Heat Transfer Convection Equation and Calculator is the transfer of heat from one place to another by the movement of fluids
Convection Heat Transfer Coefficients Equations and Calculators Simplified relations for natural convection heat transfer coefficients for various geometries in air at atmospheric pressure for laminar flow conditions.
Heat Loss from a Pipe Equation and calculator will determine the heat loss through a bare pipe
Heat Sink Convection with Fins Calculator Fins are used to increase heat transfer area and provide a cooling effect.
Heat Radiation of a Surface Calculator Heat Radiation of a Surface Calculator
Estimating Junction Heat Transfer and Temperature of a Transistor Equation and Calculator
Heat Transfer Application
APM® Alloy Heating Tubes Review APM is iron-chromium-aluminium (Fe-Cr-AI) powder metal alloy
Bayonet Heating Elements Review Constructed with inline configurations and have electrical plugin "bayonet" connector to facilitate quick installation and removal.
Coefficients Linear Thermal Expansion Thermal expansion is the tendency of matter to change in volume in response to a change in temperature, through heat transfer.
Coil Heating Elements Review Heating elements work by converting electricity into heat energy, are rated in watts, however heat energy transfer varies by design.
Compression Tension Stress Linear Thermal Expansion Equation and Calculator Compression or Tension Stress is the change in stress due to the material expansion by the change of temperature.
Insulation Blanket Applications and Capabilities Overview When selecting the appropriate material for an insulation application, material galvanic capabilities, temperature range, and installation requirements should be understood
Insulation Material Thermal Conductivity Chart Various Insulation Material Thermal Conductivity Table

1 Heat transfer is steady since there is no indication of any change with time.
2 Heat transfer is one-dimensional since there is thermal symmetry about the centerline and no variation in the axial direction.
3 Thermal conductivities are constant. 4 The thermal contact resistance at the interface is negligible.

Heat Losses From Bare and Insulated Pipe Heat Loss in Btu/h/ft Length of Fiberglass Insulation and Bare Pipe, ASJ Cover 150°F Temperature of Pipe Horizontal
Heat Loss from Pipe Outdoors Heat Loss from Piping Chart For Piping Intended to Be Installed Outdoors
Heat Loss Insulated Pipe Equation and Calculator Equation and calculator will determine the conductive heat loss through a cylinder or pipe wall insulation.
Heat Transfer Coefficient Calculations This Worksheet will allow you to calculate heat transfer coefficients (h) for convection situations that involve internal flow in a tube of given cross-section. Premium membership required
Ribbon Heating Elements Review Ribbon coil heating elements
Rod Heating Elements Review Rod Heating Elements are cylindrical heating components of various lengths
Thermal Energy Created by the Human Body he body is a heat engine. It converts chemical energy of the food consumed into both heat to sustain metabolism and work.
Thermal Properties of Common Building Materials The materials' thermal properties govern the rate of heat transfer between the inside and outside of the building, the amount of heat that can be stored in the material..
Convection Heat Transfer
Convective Heat Transfer Coefficients Table Chart Convective Heat Transfer Coefficients Table Chart
Convective Heat Transfer Convection Equation and Calculator Convection is usually the dominant form of heat transfer in liquids and gases.
Overall Heat Transfer Coefficient Overall Heat Transfer Coefficient Equation
Convection Heat Transfer Convection Heat Transfer calculation example
Thermal Radiation Radiant heat transfer involves the transfer of heat by electromagnetic radiation that arises due to the temperature of a body
Black Body Radiation A body that emits the maximum amount of heat for its absolute temperature is called a black body.
Emissivity and Heat Transfer Emissivity Equation
Radiation Configuration Factor Radiative heat transfer rate between two gray bodies equation.
Solar Radiation Incident on the Surface of Earth Hourly variation of solar radiation incident on various surfaces and the daily totals throughout the year at 40° latitude
Heat Transfer Terminology
Heat and Temperature Temperature is a measure of the amount of energy possessed by the molecules of a substance.
Heat and Work Energy terms heat and work both represent energy in transition
Modes of Transferring Heat Heat is always transferred when a temperature difference exists between two bodies.
Heat Flux Heat Flux equation - The rate at which heat is transferred
Thermal Conductivity Heat transfer characteristics of a solid material are measured by a property called the thermal conductivity (k) measured in Btu/hr-ft-°F.
Log Mean Temperature Difference Temperature change between two fluids across the heat exchanger is best represented by the log mean temperature difference
Convective Heat Transfer Coefficient Convective heat transfer coefficient is sometimes referred to as a film coefficient
Overall Heat Transfer Coefficient Overall Heat Transfer Coefficient Equation
Bulk Temperature Fluid temperature (Tb), referred to as the bulk temperature, varies according to the details of the situation.
Water Boiling Graph Curve at 1 Atmosphere Typical Water Boiling Graph Curve at 1 Atmosphere
Conduction Heat Transfer
Conduction and Heat Transfer Conduction involves the transfer of heat by the interaction between adjacent molecules of a material.
Equivalent Resistance Method Equivalent Resistance Method equation and calculation example
Electrical Analogy Heat Tranfer Electrical Analogy Heat Transfer equation and calculation
Conduction-Cylindrical Coordinates Heat transfer across a rectangular solid is the most direct application of Fouriers law.
Overall U-factors (heat transfer coefficients) for various windows and skylights Overall U-factors (heat transfer coefficients) for various windows and skylights in W / (m 2 · °C)
Interior and Exterior Surface Heat Transfer Coefficients Equations for Windows Heat transfer through a window is also affected by the convection and radiation heat transfer coefficients between the glass surfaces and surroundings.
Heat Loss from Ducts in a Building Equation and Calculator Heat Loss from Ducts in a Building Equation and Calculator and cost of energy lost.
Heat Conduction through a Wall Equation and Calculator Heat Conduction through a wall equations and calculator.
Steady State Conduction Multi layer Isothermal Walls Calculation Steady State Conduction Multilayer Isothermal Walls Calculation and equation
Thermal Conductivity Conversions Conversions Factors for Thermal Conductivity Unit
Thermal Conductivity of Gases Table of thermal conductivity of gases as a function of temperature.
Thermal Conductivity of Common Metals and Alloys Table gives typical values of thermal several common commercial metals and alloys.
Thermal Conductivity Common Liquids Thermal Conductivity of Liquids Table

Heat Exchangers

Heat Exchangers Transfer of heat is usually accomplished by means of a device known as a heat exchanger.
Parallel and Counter-Flow Designs Parallel and Counter Flow heat exchanger Designs
Non-Regenerative Heat Exchanger The non-regenerative application is the most frequent and involves two separate fluids.
Regenerative Heat Exchanger Regenerative heat exchanger typically uses the fluid from a different area of the same system for both the hot and cold fluids.
Cooling Towers Typical function of a cooling tower is to cool the water of a steam power plant by air that is brought into direct contact with the water.
Log Mean Temperature Difference Application to Heat Exchangers To solve certain heat exchanger problems, a log mean temperature difference or must be evaluated.
Overall Heat Transfer Coefficient Overall Heat Transfer Coefficient Across Heat Exchanger Tubes Equation
Overall Heat Transfer Coefficients in Heat Exchangers Representative values of the overall heat transfer coefficients in heat exchangers.
Empirical correlations for the average Nusselt number for forced convection over a flat plate and circular and noncircular cylinders in cross flow

Heat Transfer Engineering Reference Data

Properties of air at 1 atm pressure Engineering properties of air at 1 atm pressure
Thermal contact conductance of some metal surfaces in air (from various sources) table
Unit thermal resistance (the R-value) of common components used in buildings
Unit thermal resistances (R-values) of well-sealed air spaces (from ASHRAE Handbook of Fundamentals, Ref. 1, Chap. 22, Table 2)
Saturation pressure of water at various temperatures
Boiling and freezing point properties of selected substances
Thermal Properties of insulating materials (at a mean temperature of 24°C)
Combined natural convection and radiation thermal resistance of various heat sinks used in the cooling of electronic devices between the heat sink and the surroundings. All fins are made of aluminum 6063T-5, are black anodized.