Evaporative cooler

An evaporative cooler lowers air temperature by evaporating water into a moving airstream, usually through a wetted pad. It works best where outdoor air is hot and dry.

Evaporative cooling: Cooling produced when a liquid absorbs heat as it changes into vapor. The device uses this heat-absorbing phase change to lower air temperature.
Cooling pad: A porous medium wetted with water to expose a large surface area to passing air. Air passes through this component while water evaporates from its surface.
Desert cooler: A household evaporative cooler designed for hot, dry climates, commonly using a wetted pad and fan. It is the familiar room-scale form of the device.
Air conditioning: The controlled treatment of indoor air to regulate temperature, humidity, cleanliness, or circulation. Refrigeration-based air conditioning can cool without relying on outdoor air’s evaporation capacity.
Wet-bulb temperature: The lowest temperature attainable by evaporating water into air at a given pressure and humidity. It sets the practical lower limit for direct evaporative cooling.
Axial fan: A fan that moves air parallel to its rotational axis. Many coolers use one to draw or push air through the wetted pad.
Cooling tower: A heat-rejection structure that cools water by exposing it to air and allowing some water to evaporate. It applies evaporative heat transfer to cooling water rather than directly cooling room air.
Vapor-compression refrigeration: A refrigeration cycle that moves heat using a circulating refrigerant compressed and expanded through components. Unlike an evaporative cooler, it can cool air below outdoor wet-bulb temperature.
Psychrometrics: The study of the thermodynamic properties of moist air and their relationships. Its humidity and enthalpy relationships explain the cooler’s air-state changes.
Water pump: A machine that moves liquid by converting mechanical energy into fluid pressure and flow. It circulates water from the reservoir to the cooling pad.

Linked from 4 pages