What is the English unit of heat measurement?

The unit of heat measurement in the English system is the British thermal unit, commonly known as Btu. A Btu is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at a constant pressure. This unit is widely used in heating and cooling applications, particularly in the context of air conditioning and refrigeration systems, making it particularly relevant for professionals in the field.

The other options represent different types of energy or heat measurement units but are not used primarily within the English unit system. For instance, the calorie is a metric unit measuring heat, primarily in the context of nutrition and science, while the joule is utilized in both the metric and SI (International System of Units) systems to quantify energy. The newton is a unit of force and does not pertain to heat measurement. Understanding these distinctions is important for practical applications in refrigeration and HVAC systems, where accurate measurement of heat is critical for efficiency and performance.