ICC Commercial Mechanical Practice Exam

The function of a heat exchanger in HVAC systems is to transfer heat between two or more fluids without allowing them to mix. This process is crucial for efficient heating and cooling operations. In practical terms, a heat exchanger works by allowing one fluid, which is often a refrigerant, to absorb or release heat to another fluid, which could be air or water. The design of the heat exchanger ensures that while heat can flow from one fluid to another, the two do not come into direct contact, thus preventing contamination and maintaining the integrity of each fluid's properties.

This capability is essential in various applications within HVAC systems, such as in air conditioning units, where heat must be removed from the refrigerant so it can absorb more heat from the indoor environment. It also plays a significant role in boiler systems, where heat is transferred from the combustion products to water without mixing.

The other options, while related to HVAC operations, do not accurately describe the fundamental role of heat exchangers. For example, increasing the temperature of one fluid, filtering air particles, or cooling refrigerants are specific actions that may involve heat exchangers or other components but do not define their primary function.