Sensible heat is the energy required to change the temperature of a substance without altering its phase or state of matter. In HVAC systems, sensible heat cooling or heating results in a measurable temperature change that can be detected by a thermometer. This differs from latent heat, which changes the phase of a substance without affecting temperature.
HVAC Applications
Sensible heat load calculations are critical for sizing air conditioning and heating equipment. A typical residential cooling system removes both sensible and latent heat, with sensible heat typically accounting for 60 to 75 percent of total cooling load in standard climates. Ductwork design, coil selection, and compressor capacity all depend on accurate sensible heat measurements.
Technical Significance
Sensible heat is measured in BTU (British Thermal Units) per hour. The sensible heat ratio (SHR) compares sensible cooling capacity to total cooling capacity and typically ranges from 0.6 to 0.8 for residential systems. Understanding sensible heat helps technicians diagnose performance issues and optimize system efficiency for occupant comfort.