Heat Transfer Mechanisms

A solid consists of low kinetic energy vibrating particles locked into position by interparticle attractive forces. When heat is applied, energy is absorbed and the particles start vibrating more vigorously.

Water vapour at 373K has more energy than water at 373K as the steam has absorbed latent heat of vaporisation to change the state. Therefore the more burning sensation.

Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process that is specified in some way. An example is latent heat of fusion for a phase change, melting, at a specified temperature and pressure. Latent heat is associated with the phase changes of atmospheric water vapor, mostly vaporization and sublimation.

The more light the object absorbs, the more heat absorbed since light is energy. If you consider it a color, black absorbs the most heat. A black object absorbs all wavelengths of light and reflects none. Objects that are white, on the other hand, reflect all wavelengths of light and therefore absorb the least heat.

Conduction, convection, radiation, all the 3 processes involves heat transfer.

Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection. Conduction is the transfer of energy through matter from particle to particle. 

On heating a liquid, heat absorbed by its molecules is absorbed and stored in the form of potential energy.

On the heating matter, the kinetic energy of particles increases, so they gain energy and on the cooling matter, the particle's the motion of particles decreases, so they lose energy.

In addiiton to the temperatre steam has latent heat of vapourization which it acquires after converting into steam from water.

A solid consists of low kinetic energy vibrating particles locked into position by interparticle attractive forces. When heat is applied, energy is absorbed and the particles start vibrating more vigorously.
Finally, the vibrations become energetic enough to overcome the attractive forces, and the particles start sliding out of their positions to flow about. The solid is now melting into a liquid.

Evaporation involves conversion of liquid to vapor which happens when latent heat is absorbed by the liquid.

A condenser is simply a heat exchanger,the purpose of a condenser in the cycle of compression refrigeration is to change the hot gas being discharged from the compressor to a liquid prepared for use in the evaporator. The condenser accomplishes this action by the removal of sufficient heat from the hot gas, to ensure its condensation at the pressure available in the condenser. The heat is shifted to another medium, like water or air, to cool the condenser.

A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. In most cycles it undergoes phase transitions from a liquid to a gas and back again.A heat pump is a device that transfers heat energy from a source of heat to what is called a "heat sink". Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses a small amount of external power to accomplish the work of transferring energy from the heat source to the heat sink.

A refrigerator works by absorbing heat from its interior and releasing it into the surrounding room through the condenser coils at the back. When the door is kept open, the refrigerator draws in more warm room air and continuously runs, ultimately expelling more heat into the room than it removes, causing the room temperature to rise.

Heat spontaneously flows from a hotter to a colder body. The rate at which energy is conducted as heat is a function of temperature. Hence heat flows as a result of temperature.