HVAC & Refrigeration Engineering
Psychrometrics, thermal load calculation, vapor-compression refrigeration, and building ventilation.
Theory Modules
Study the theory, review the governing formula, and test your knowledge with interactive questions.
Air Conditioning Load
The air conditioning load is the rate at which heat and moisture must be removed from (cooling load) or added to (hea...
Compressors
A compressor adds shaft work to a gas to increase its pressure and usually its temperature. For a steady-flow compres...
Condensers
Condensers are heat exchangers used in refrigeration and HVAC systems to reject heat from the refrigerant to the surr...
Dew Point
Dew point temperature (T_dp) is the temperature at which air becomes saturated (100% relative humidity) and water vap...
Energy Efficiency (HVAC)
HVAC energy efficiency focuses on minimizing the energy required to maintain indoor thermal comfort and air quality....
Evaporators
The evaporator is a critical heat exchanger in a vapor-compression refrigeration cycle. Its primary function is to ab...
Expansion Valves
An expansion valve meters liquid refrigerant from the high-pressure side of a refrigeration or heat-pump system into...
Fans
A fan is a turbomachine that moves air or gas by adding mechanical energy to the fluid, producing a pressure rise tha...
Heat Pumps
A vapor-compression heat pump moves heat from a low-temperature source to a higher-temperature sink. In heating mode,...
Humidity
Humidity quantifies the amount of water vapor present in air and is a critical parameter in HVAC design, thermal comf...
HVAC Fundamentals
HVAC (Heating, Ventilation, and Air Conditioning) fundamentals cover the principles and systems used to control indoo...
Psychrometry
Psychrometry is the study of the thermodynamic properties of moist air (a mixture of dry air and water vapor) and the...
Refrigeration Cycles
Refrigeration cycles operate on the principle of transferring thermal energy from a low-temperature region to a high-...
Relative Humidity
Relative humidity (RH) expresses how close moist air is to saturation at a specified temperature. It is defined as th...
Sensible / Latent Heat
In moist air (psychrometrics), heat transfer is divided into sensible and latent components. Sensible heat changes th...
Ventilation
Ventilation is the process of supplying outdoor air to indoor spaces to maintain air quality, dilute contaminants, an...