Course Description

Heat rejection is the process of transferring unwanted heat from a refrigeration or air conditioning system to the ambient environment. In simple terms, every cooling system moves heat from where it is not wanted-inside a building-to where it is less objectionable-the outdoors. However, this transfer is not automatic; it requires dedicated equipment and energy input. In HVAC applications, we have three primary methods: evaporative, which uses water evaporation; dry, which uses ambient air only; and adiabatic, a hybrid that pre-cools air with small amounts of water. The choice of equipment directly impacts chiller efficiency. If you can reject heat at a lower temperature-for example, supplying cooler water to a chiller condenser-the chiller’s coefficient of performance improves dramatically. Conversely, poor heat rejection forces the chiller to work harder, consuming more electricity. This relationship between heat rejection and chiller performance is the central theme of our course.

What you'll learn in this course?

• Differentiate between the primary types of heat rejection equipment: cooling towers, dry coolers, evaporative condensers, and hybrid systems.

• Explain the thermodynamic principles of wet, dry, and adiabatic heat rejection, including approach temperature and range.

• Select appropriate heat rejection equipment based on climate, water availability, space constraints, and energy codes (ASHRAE 90.1).

• Identify common operational issues such as fouling, legionella risk, freezing, and fan energy consumption.

• Calculate basic sizing parameters and compare life-cycle costs for different heat rejection options.

Prerequisites

• Basic knowledge of HVAC refrigeration cycles, condensers, pumps, and heat transfer

• Familiarity with building mechanical systems and basic engineering calculations is helpful