Puron® Is The Key To Quantum PlusTM Performance.   At Bryant, we believe that heating and cooling equipment should offer lasting comfort and value. That’s why we designed the Quantum Plus air conditioners with Puron. In addition to the comfort and reliability you’d expect from a Bryant product, the Models 550A, 552A, and 556A offer Puron, the environmentally sound alternative to refrigerants currently in use. 1. Puron™ Refrigerant is chlorine-free to provide environmentally sound performance and meet upcoming government regulations.  This refrigerant offers higher levels of energy efficiency and helps protect you from future costs of servicing product with Freon-22 refrigerant. 2. AeroQuiet™ System utilizes a patented design to move air more easily, reducing sound and increasing fan efficiency.  The motor is totally enclosed for durability season after season. 3. High-Efficiency Scroll Compressor has a more powerful motor and heavier construction than standard scroll compressors for reliable operation.  A compressor sound hoot makes the Quantum Plus units extra quiet. 4. High & Low Pressure Switches ensure reliability and protect the most important component in your air conditioner - the compressor - for years of dependability. 5. DuraGuard™ Coil Guard helps avoid damage from rocks and other debris to keep the unit running efficiently.