MODULE 2. Heat Pump Market Developments.

This module reviews current market developments in heat pump technology, explaining how shifts in refrigerants, thermodynamic cycle design, and component innovation are shaping today’s commercial and domestic systems. It outlines how manufacturers integrate advanced compression schemes, natural refrigerants, and high-efficiency heat exchangers to meet tightening environmental and performance requirements.

Lesson 9 presents the single-stage vapor compression cycle, surveying state-of-the-art commercial units using this cycle.

Lesson 10 introduces two-stage compression with vapor injection, explaining economizer and flash-tank configurations, their effects on interstage pressures, discharge temperature, and cold-climate capacity, and their implementation in enhanced vapor-injection compressors.

Lesson 11 examines cascade systems, outlining the separation of low- and high-temperature circuits, the function of the cascade heat exchanger, refrigerant selection, and applications requiring high lift or staged temperature levels, including parallel, series, and hybrid configurations.

Lesson 12 covers CO₂ transcritical systems, detailing the role of the gas cooler, high-pressure operation, and the influence of CO₂’s critical and triple points. It compares several CO₂-based architectures and presents commercial high-temperature DHW systems such as the Mitsubishi QAHV.

Lesson 13 reviews natural refrigerants (hydrocarbons, CO₂, and ammonia) addressing thermodynamic behavior, safety classes, flammability and toxicity management, and representative domestic products. It concludes with an overview of EU regulatory frameworks that guide refrigerant selection and system design.