Skip to content

Class: HeatFlow

The HeatFlow class is a subclass of Variable designed to represent the total heat transfer rate. It ensures accurate calculations by storing all values internally in its base SI unit, Watts (W).

Supported Units

The following units are supported for initialization and conversion.

Unit str Conversion Factor to Watts (W)
Watts W 1
kilowatts kW 1000
megawatts MW 106
British Thermal Units per hour BTU/h 0.293071
calories per second cal/s 4.184
kilocalories per hour kcal/h 1.163

Class Reference

class HeatFlow(value, units='W')

A class for handling heat flow measurements with automatic unit conversion.

Parameters:

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

Raises:

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

Examples: 

# Create a HeatFlow object of 5000 Watts  
>>> Q1 = HeatFlow(5000, "W")

# Create a HeatFlow object of 5 kilowatts  
>>> Q2 = HeatFlow(5, "kW")

Properties

Property Type Description
.value float The numeric value of the heat flow, always in Watts (W). 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 HeatFlow 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:

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

Raises:

  • TypeError : If target_unit is not a valid unit.

Examples: 

# Initialize a heat flow of 5000 Watts  
>>> heat_flow_W = HeatFlow(5000)

# Convert to kilowatts  
>>> heat_flow_kW = heat_flow_W.to("kW")

>>> print(heat_flow_kW)  
5.0 kW

String Representation

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