From the simple air conditioning units that cool homes to the robust systems that can manage industrial complexes, HVAC systems ensure proper temperature control and comfort through their use. By taking advantage of thermodynamics, fluid power, and heat transfer, HVAC systems can either heat or cool buildings and regulate humidity as needed. With varying types of HVAC systems being available on the market, it can be useful to be aware of the roles and functionalities of each to make a more well-informed purchasing decision.