Skip to content

Class: HeatOfVaporization

The HeatOfVaporization class is a subclass of Variable designed to represent the heat required to change a unit mass of a substance from liquid to gas at a given pressure. It ensures accurate calculations by storing all values internally in its base SI unit, Joules per kilogram (J/kg).

Supported Units

The following units are supported for initialization and conversion.

Unit str Conversion Factor to Joules per Kilogram (J/kg)
Joules per kilogram J/kg 1
kilojoules per kilogram kJ/kg 103
megajoules per kilogram MJ/kg 106
calories per gram cal/g 4184
British Thermal Units per pound BTU/lb 2326

Class Reference

class HeatOfVaporization(value, units='J/kg')

A class for handling heat of vaporization measurements with automatic unit conversion.

Parameters:

  • value : float or int
    The numeric value of the heat of vaporization. Must be a non-negative number.
  • units : str, default='J/kg'
    The unit of the provided value. Must be one of the supported units.

Raises:

  • ValueError : If value is negative or units is not a valid unit.

Examples: 

# Create a HeatOfVaporization object of 2.257 MJ/kg  
>>> hv1 = HeatOfVaporization(2257000)

# Create a HeatOfVaporization object of 540 cal/g  
>>> hv2 = HeatOfVaporization(540, "cal/g")

Properties

Property Type Description
.value float The numeric value of the heat of vaporization, always in Joules per kilogram (J/kg). This is the internal representation used for all calculations.
.original_value float The numeric value as provided during initialization.
.original_unit str The unit as provided during initialization.

Methods

to(target_unit)

Returns a new HeatOfVaporization object converted to the target_unit. The original object remains unchanged.

Parameters:

  • target_unit : str
    The unit to convert to. Must be one of the supported units.

Returns:

  • HeatOfVaporization
    A new HeatOfVaporization object with the same value, represented in the target unit.

Raises:

  • ValueError : If target_unit is not a valid unit.

Examples: 

# Initialize a heat of vaporization of 2257000 J/kg  
>>> water_hv = HeatOfVaporization(2257000, "J/kg")

# Convert to cal/g  
>>> water_hv_cal = water_hv.to("cal/g")

>>> print(water_hv_cal)  
540.057352 cal/g

String Representation

  • __str__(self)
    Returns a human-readable string representation of the heat of vaporization, rounded to six decimal places, using its original value and unit.
  • __repr__(self)
    Returns an unambiguous string representation suitable for developers and debugging.