Understand sensible and latent heat and why air conditioning must control both air temperature and moisture for good summer comfort.
Sensible heat changes temperature and can be observed with a dry-bulb thermometer. Latent heat involves moisture and phase change without appearing directly as a simple air-temperature change.
During cooling, the evaporator handles both loads: it lowers air temperature and condenses water vapor from the air when the coil is below the dew point.
The proportion of sensible and latent work affects equipment selection, airflow and comfort.
Heat that changes dry-bulb temperature.
Energy associated with moisture in the air.
Temperature at which moisture begins to condense from air.
Water removed from indoor air during dehumidification.
The sensible portion of total cooling capacity.
Airflow can influence the balance between sensible cooling and moisture removal.
Many service symptoms are easier to understand when you know what the system is trying to do. Pressure, temperature, airflow, heat transfer and controls are connected; a change in one can affect several measurements elsewhere in the system.
Professional HVAC diagnosis may require electrical meters, refrigeration gauges and temperature probes, airflow or static-pressure instruments, combustion analyzers and manufacturer-specific procedures. The Academy explains the concepts without encouraging unsafe internal testing.
Connect pressure, temperature and phase change.
Understand the air side of the system.
Review the complete system in homeowner terms.
Look up unfamiliar HVAC terminology.
Use the Learning Center for homeowner-focused explanations, the Troubleshooting Center for symptoms, and the Buying Guides when you are evaluating equipment or proposals.
Connect the technical concept to the complete residential system.
Look up related components, measurements and trade terminology.