Using Appropriate Diagrams And References, The Three Main Mechanisms Of Heat Transfer Relevant For Building Services Engineering

In our physical world, there are a multitude of phenomenon that occur daily that we experience that often go unnoticed. It contains a vast array of conceptual applications and the equations applied to them in order to better explain and calculate the phenomenon involved. In a normal occurrence an individual can explain and calculate certain aspects of movement and processes that are also involved with it. When dealing with the transferring of heat and various process related to heat, the terms convection, conduction and radiation are frequently discussed thoroughly. The overall field of thermodynamics involves the study of thermal processes in physical systems. Some terms involved with these particular concepts include: closed system, empirical law, free energy, joule’s law, specific, temperature, and thermodynamics. The general defined term of convection is “the heat transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it” (Georgia State University). “In the world of physics, the term conduction is usually defined as a form of heat transfer by the way of molecular tension inside an object or material that does not show any individual motion in its entirety” (Georgia State University). Radiation by means of physics related terms is defined as “the emission or transmission of energy in the form of waves or particles through a

Heat: The amount of energy associated with the movement of atoms and molecules in matter.

Thermal energy is the energy a substance or system has related to its temperature. This means the energy of moving or vibrating molecules. Atoms and molecules are always in motion. Generally the motion of thermal energy cannot be seen, but instead the effects it has on the substance can be seen or felt. Thermal energy can have several different uses. It can be used to heat homes, cook food, and generate electricity.

2. Conduction heat loss by direct molecule to molecule transfer from one surface to another. (skin loses heat through direct contact with cooler air, water, or other surfaces)

There are four basic components for thermal energy (heat): 1. All matter is made up of tiny particles called atoms. These can only be seen with special microscopes. 2. The atoms are always moving – they all have kinetic energy. 3. The particles have space between them. Different states of matter have different amounts of space. 4. Adding heat (energy) to matter makes the particles move more quickly. Since faster moving things have more kinetic energy, adding heat increases the energy of the particle. 5. Cooling it down decreases the amount of kinetic energy and slows the movement down.

It is where heat is transmitted to a material which is generally a metal as they are good conductors while gases and non-metals are generally

Heat energy (or just heat) is a form of energy which transfers among particles in a substance (or system) by means of kinetic energy of those particles. Heat energy can be transferred by four different methods such as conduction, radiation, convection, and latent heat transfer. In conduction, the heat spreads through a substance when faster atoms and molecules collide with neighboring slower ones and it transfers some of their kinetic energy to them. A great example of conduction is when you can warm your back muscles with a heating pad. Radiation is the process where heat emanates from an object that

A good conductor of heat would be metal, because electrons are free to bounce around and move very fast, while non-metals such as fibers, spun glass and other dense material restricts the free flow of electrons, making them slow.

Heat from the fire chamber is channeled up the chimney, where there is a pot or pan is resting on the grates. The heat is concentrated in the insulated chimney, thus, less heat loss through conduction. The insulation around the chimney can withstand temperatures up to 2000° F. This means the heat is not conducted through the metal

The concept of using radiant and convection heat for comfort has been around since early man. People chose south facing caves because the sun would warm up the rocks during the day and radiate the heat into the cave at night. The flames from a fire also gave off radiant heat. Technology has developed to control radiant and convection heat. Radiant heating and cooling (RHC) systems utilize the surrounding surfaces as heating and/or cooling sources. Generally, RHC systems are systems that radiant heat transfers cover more than 50% of heat exchange within a specified space. Compared to all-air systems, which depend on convection only, the RHC system provides heating and cooling by the combination of radiation and convection in a building. There are three types of radiant floor heating systems. The first type is a radiant air floor, where the air is the heat-transferring medium. The second type is electric radiant floor. The last type is hydronic radiant floor, which uses hot water.

Whenever two objects of different temperature are brought together, thermal energy passes from the warmer to the cooler object until the two are the same temperature.

The rate of heat loss by a surface through convection depends on the wind speed above that surface.

Heat is a form of energy that is transferred between two substances at different temperatures. The flow of the energy is from the object of higher temperature to the object of lower temperature. The heat is measured in units of energy, usually calories or joules. Temperature on the other hand, is how cold or hot an object is. The temperature is the average kinetic energy per molecule of a substance. This is measured in degrees on the Celsius or Fahrenheit or in Kelvins.

Heat transfer processes are prominent in engineering due to several applications in industry and environment. Heat transfer is central to the performance of propulsion systems, design of conventional space and water heating systems, cooling of electronic equipment, and many manufacturing processes (Campos 3).

To conduct a proper analysis of the 1-D transient conduction in a plane wall we must take the necessary mathematical procedures to obtain an analytical model that accurately represents the heat transfer that occurs. The equation must accurately model a plane wall that has a thickness L, is well-insulated on one side, but is still vulnerable to convection on the other side. In order to complete the model, one must scale the problem in terms of both a length scale and a time scale to transform the variables to a dimensionless form that allows for a set of solutions that can be narrowed down to the simple parameter, Bi=hL/k.