Heat & Thermodynamics
The Alphabet Soup
100

 This type of heat changes a substance's temperature without changing its state.

 What is sensible heat?

100

These early refrigerants, like R-11 and R-12, contain chlorine, fluorine, and carbon, and were phased out due to high ozone-depletion potential.

 What are CFCs (Chlorofluorocarbons)?  

200

 This is the heat absorbed or released during a change of state, such as a liquid changing to a vapor.  

 What is latent heat?

200

R-22 belongs to this family of partially halogenated refrigerants that contain hydrogen, chlorine, fluorine, and carbon.

: What are HCFCs?  

300

These charts give the saturation pressure corresponding to a saturation temperature, but they do not directly predict the pressure or temperature of superheated vapor.

What are Pressure-Temperature (PT) charts?

300

These refrigerants, like R-134a, contain no chlorine and have zero ODP, but many still possess high global-warming potential (GWP)

What are HFCs?

400

 This condition occurs when a liquid is cooled below its saturation temperature

What is subcooled liquid?

400

Containing double bonds that help them break down rapidly after release, these refrigerants have zero ODP and very low GWP.  

What are HFOs

500

 The operating-pressure category of a refrigerant is based on its liquid saturation pressure at this specific boiling temperature.

 What is 104°F?

500

To determine the chemical composition (carbon, hydrogen, and fluorine atoms) of many single-component halogenated refrigerants, you add this specific number to the refrigerant number.  

 What is 90?  

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