There is a lot of science that goes into heating and cooling systems, and the professionals who work on your business or organization’s energy management system must have a solid understanding of basic thermodynamic principles. Here’s an informative science blog from Hartford’s trusted HVAC professionals at the Tradesmen of New England. This time, we’ll explore the three ways that thermal energy can be exchanged from one object to another.


The first way that heat energy can be transferred is by radiation. Hot objects give off infrared waves. When these waves are absorbed by another object, there is an increase in energy that contributes to a higher temperature. For example, a piece of iron left in a fire will begin to glow. If you pull it out of the fire and hold your hand close to it, you will feel the heat right away. Energy transfer by radiation does not require actual contact between the two objects.


When two objects of different temperature do come into contact, thermal energy is exchanged by the process of conduction. The hotter object will decrease in temperature and the cooler one will increase until their temperatures have equalized. On a molecular level, this heating and cooling occurs when the particles that comprise one material collide with those of the other, thereby imparting some of their momentum, which is essentially what temperature measures.


Forced air HVAC systems rely on convection to be effective. Convection is simply changing the temperature of an area by introducing different air. For example, a furnace heats air, which is then moved by fans into a different area of a building. When the warmer air is introduced into a room, the temperature increases.