Which measurement unit corresponds to heat energy?

Heat energy is primarily measured in joules, but in many practical contexts, especially in relation to power usage, watts are a relevant unit. A watt is defined as one joule per second, quantifying the rate at which energy is transferred or converted. In the study of fire behavior, understanding this relationship is critical because it helps in assessing how quickly heat energy is generated and impacts surrounding materials and conditions.

The other units mentioned serve different purposes: lumens measure the quantity of light emitted by a source, pascals measure pressure, and kelvins measure temperature on an absolute scale. None of these directly correspond to the measurement of heat energy at the same level that watts do, making watts the most appropriate choice in this context.