Air Conditioning Repair Certification (ETI) Practice Exam 2025 - Free Air Conditioning Repair Practice Questions and Study Guide

Heat is typically transferred in fluids through convection, which is the process of heat transfer by the movement of a fluid. In convection, warmer portions of the fluid rise while cooler areas sink, creating a circulation pattern that effectively distributes heat throughout the fluid. This process is essential in applications such as heating and cooling systems, where air or liquid must efficiently transmit thermal energy.

Convection occurs in both liquids and gases and can be classified into two types: natural convection, driven by buoyancy forces resulting from temperature differences, and forced convection, which involves an external force such as a pump or fan to induce fluid motion.

While conduction is a method of heat transfer through direct contact between materials and radiation involves the transfer of energy through electromagnetic waves without the need for a medium, these processes do not apply specifically to fluids in the same way that convection does. Concentrated energy is not a recognized method of heat transfer but may refer to the focus of energy in a specific area, lacking context in standard thermodynamics.