Trane Heating and Air Conditioning Units. Types of refrigerants: Blends Azeotropic. 

An azeotropic blend is generally a mixture of two substances that behave as if they were a pure fluid. When they add or remove heat, the composition (molecular fraction) of vapor and liquid remain essentially unchanged throughout the process. In other words, in a blend with 50% of fluid A and 50% B fluid, fluid per molecule it evaporates or condenses, a molecule of fluid B does the same. 

A zeotropic blend is a mixture of refrigerants that have different levels of volatility when observing the performance of the refrigeration cycle. For example, a molecular change in the composition and / or a change in the saturation temperature during boiling or condensation, in this way, it behaves as a single component refrigerant as it condenses or evaporates. 

The Montreal Protocol requested the suspension of production and consumption of all fluorocarbon refrigerants (CFCs) and hydrochlorofluorocarbons (HCFCs), and from the entry into force of the protocol, the air conditioning industry and refrigeration is committed to the community to establish substitute refrigerants for the ozone layer deteriorate.

Since then, a large number of refrigerants has been introduced worldwide, of which some are long-term alternative, and others are of the transitional type. With the increasing attention to the problem of deterioration of the ozone layer, there is now more pressure to adopt the new refrigerants with little or no global warming.