Refrigeration heat recovery systems can be integrated with existing HVAC systems through a secondary heating circuit. This circuit receives the recovered heat from the refrigeration process and distributes it to various parts of the building, such as space heating, hot water systems, or process applications. The integration process typically involves designing and installing additional components, such as heat exchangers, pumps, and control systems, to ensure seamless interaction between the refrigeration heat recovery system and the existing HVAC infrastructure.