Room air distributionRoom air distribution is characterizing how air is introduced to, flows through, and is removed from spaces. HVAC airflow in spaces generally can be classified by two different types: mixing (or dilution) and displacement. Mixing systems generally supply air such that the supply air mixes with the room air so that the mixed air is at the room design temperature and humidity. In cooling mode, the cool supply air, typically around 55 °F (13 °C) (saturated) at design conditions, exits an outlet at high velocity.
Computer coolingComputer cooling is required to remove the waste heat produced by computer components, to keep components within permissible operating temperature limits. Components that are susceptible to temporary malfunction or permanent failure if overheated include integrated circuits such as central processing units (CPUs), chipsets, graphics cards, and hard disk drives. Components are often designed to generate as little heat as possible, and computers and operating systems may be designed to reduce power consumption and consequent heating according to workload, but more heat may still be produced than can be removed without attention to cooling.
Newton's law of coolingIn the study of heat transfer, Newton's law of cooling is a physical law which states that The rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its environment. The law is frequently qualified to include the condition that the temperature difference is small and the nature of heat transfer mechanism remains the same. As such, it is equivalent to a statement that the heat transfer coefficient, which mediates between heat losses and temperature differences, is a constant.
EvaporatorAn evaporator is a device used to turn a liquid into a gas. Some air conditioners and refrigerators use compressed liquids with a low boiling point that vaporizes within the system to cool it, whilst emitting the thermal energy into its surroundings. Evaporators are often used to concentrate a solution. One example is the climbing/falling film plate evaporator, which is used to make condensed milk. Similarly, reduction (cooking) is a process of evaporating liquids from a solution to produce a "reduced" food product, such as wine reduction.
EmissivityThe emissivity of the surface of a material is its effectiveness in emitting energy as thermal radiation. Thermal radiation is electromagnetic radiation that most commonly includes both visible radiation (light) and infrared radiation, which is not visible to human eyes. A portion of the thermal radiation from very hot objects (see photograph) is easily visible to the eye. The emissivity of a surface depends on its chemical composition and geometrical structure.
Regenerative heat exchangerA regenerative heat exchanger, or more commonly a regenerator, is a type of heat exchanger where heat from the hot fluid is intermittently stored in a thermal storage medium before it is transferred to the cold fluid. To accomplish this the hot fluid is brought into contact with the heat storage medium, then the fluid is displaced with the cold fluid, which absorbs the heat. In regenerative heat exchangers, the fluid on either side of the heat exchanger can be the same fluid.
Energy auditAn energy audit is an inspection survey and an analysis of energy flows for energy conservation in a building. It may include a process or system to reduce the amount of energy input into the system without negatively affecting the output. In commercial and industrial real estate, an energy audit is the first step in identifying opportunities to reduce energy expense and carbon footprint. When the object of study is an occupied building then reducing energy consumption while maintaining or improving human comfort, health and safety are of primary concern.
Energy Saving TrustEnergy Saving Trust is a British organization devoted to promoting energy efficiency, energy conservation, and the sustainable use of energy, thereby reducing carbon dioxide emissions and helping to prevent man-made climate change. It was founded in the United Kingdom as a government-sponsored initiative in 1992, following the global Earth Summit. Energy Saving Trust is no longer public funded and is a profit for purpose company. Energy Saving Trust has regional offices in England, Wales, Northern Ireland, and Scotland and runs numerous energy advice services in the UK.
