It is installed in conjunction with the furnace or air handler. The compressor pumps a chemical known as refrigerant through the system.
Here, the supply airflow rate is constant, but the supply air temperature varies according to the thermal loads of space. These systems are generally small, and they serve a single thermal zone. Variable Air Volume VAV meets the varying heating and cooling needs of different building zones as they are energy efficient.
Hydronic systems are used for circulating hot water through the warming baseboards and radiators in floors or ceilings. The advantages of heating your home using a hydronic system are that they are quiet, efficient and durable. In the Vapour-Compression Refrigeration cycle, the refrigerant undergoes phase changes.
It is extensively used for the air-conditioning of buildings and automobiles. Auto-refrigeration is a process where an uncontrolled phase change of a hydrocarbon from the liquid state to vapour occurs. A ton describes how much heat the AC unit can remove from a home in one hour. This is measured in the British thermal unit BTU. One ton of ac removes 12, BTUs of air per hour. The amount of heat that can raise the temperature of one pound of water by one degree Fahrenheit is known as one BTU.
It is about joules. The infiltration rate is the measure of the flow rate of outside air into a building. The number of interior volume air changes that occur per hour is known as air exchange rate, I. The heat load from lighting in a building is calculated from the number of lights of each type and wattage.
Then multiply this number by the usage factor and the special allowance factor. An air handler or an air handling unit is used to condition and circulate air in the HVAC system. Its components include blowers, heating elements, filter racks and sound dampers. A fan coil unit is a device that contains a heating or cooling coil and fan. It is part of an HVAC system. They are used in residential, commercial, and buildings.
Time : Time varies. The average time is 2 hours. Bookmark Page. Two locations where a cold air return should be installed:. Open area of wall and low to the ground. Behind appliances and high on the wall. Open area of wall and high on the wall. Behind appliances and low to the ground. Which of the following is a law of thermodynamics:. Heat is a form of matter. Heat moves toward a place with higher intensity.
Heat moves toward a place with lower intensity. Heat moves toward a place with a higher temperature. How fast heat will travel. The quantity of heat. The volume of heat. How hot something feels. The temperature of heat in a substance. The quantity of heat in a substance. The velocity of heat in a substance. The heat potential of a substance. Degrees Celsius, F ahrenheit and Kelvin. International System of Units.
British Thermal Units. Board of Trade Unit. If 1 pound of water warms to 60 degrees F from 55 degrees F, what btu of latent heat will it have absorbed? What is the amount of heat energy required to evaporate 1 pound of water? In an air conditioning and refrigeration system, what occurs in an evaporator? The refrigerant absorbs the latent heat. The refrigerant evaporates latent heat. Latent heat is condensed.
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