This course provides a comprehensive understanding of thermal engineering with a focus on heat pump systems, building thermal networks, and their role in national electrification and decarbonization. It covers fundamentals like thermodynamics, heat transfer, and cycle analysis, including alternative refrigerants and property chart methods, and emphasizes hands-on learning using advanced software tools for load estimation, system design, and optimization. Students will explore HVAC&R applications across residential, commercial, industrial buildings, and data centers, focusing on integrating buildings with electric grids and car charging infrastructure to support decarbonization. The course also examines transient behaviors of heat pumps and their connection to grid-edge technologies, energy storage, and renewable energy deployment for sustainable building operations. Special emphasis is placed on the role of data centers in energy systems, highlighting their potential for demand-side management, energy storage, waste heat utilization, and contribution to resilient, low-carbon smart grids.