This note discusses performances of air conditioning systems, including heat pumps and chillers. It describes the efficiencies of systems so you can estimate how much energy a system may use. The discussion applies equally to residential, commercial, and industrial systems.
Knowing how much electricity each of your appliances uses will also give you a clearer picture of where your energy dollar is going. Powered with this knowledge, you can use energy more efficiently and trim your energy budget. If you want an estimate of how much electricity your home appliances consume, refer to the Household Appliances list below. If you want a more exact estimate, you can generally find the wattage stamped on the bottom or back of the appliance, or on its "nameplate."
Energy, as defined by my Physics teacher, Mr Ismail, back in high school, is the ability to do work. Work, in simple terms, is defined as force (F) applied to move any object, by a distance (x). Hence, if the force required to move the object is larger, i.e. moving a train (due to its steel-laden weight), then the work done per distance moved is much larger than moving a bag of cotton.
Commercial refrigeration systems in the US are mostly rated in tons of refrigeration and this term is used widely in other parts of the world. However, outside the US, cooling systems may be normally specified in kW (or MW) or in Btu/h.
We have always used the energy of the sun as far back as humans have existed on this planet. As far back as 5,000 years ago, people "worshipped" the sun. Ra, the sun-god, who was considered the first king of Egypt. In Mesopotamia, the sun-god Shamash was a major deity and was equated with justice. In Greece there were two sun deities, Apollo and Helios. The influence of the sun also appears in other religions - Zoroastrianism, Mithraism, Roman religion, Hinduism, Buddhism, the Druids of England, the Aztecs of Mexico, the Incas of Peru, and many Native American tribes.
Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. The energy sources we use to make electricity can be renewable or non-renewable, but electricity itself is neither renewable or non-renewable.
Wind is simple air in motion. It is caused by the uneven heating of the earth’s surface by the sun. Since the earth’s surface is made of very different types of land and water, it absorbs the sun’s heat at different rates. During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises, and the heavier, cooler air rushes in to take its place, creating winds.