Residential_Hvac_R_Systems

HAC 200 Applied Heating Residential HVAC/R Systems Presented by: July 20, 2010 This paper is submitted in partial fulfillment of the Associate of Science Degree in Electronic Systems and HVAC program. Presented to: Professor In the HVAC/r field there are 2 main types of systems, Commercial and Residential. While both are equally important and valuable I will be talking about Residential systems. In this paper, we will concentrate on how a Residential system works and the different types of Residential air conditioning systems how they are comprised by energy source. The most common central residential A/C system incorporates an indoor air handler unit which draws building air through return ducts from the living space, cools it by moving the air across an evaporator coil, and expels cooled and dehumidified air back into the living area through supply ducts. Liquid refrigerant is released into the interior of the evaporator, changing its state from liquid to gas, cooling the evaporator coil, which in turn cools and dehumidifies air which is blown across the coil. Refrigerant used to cool the evaporator coil runs in independent piping from the evaporator coil to a compressor and condenser unit outside where the refrigerant is re-pressurized, cooled, and returned back to the evaporator coil as a liquid. Air-cooled air conditioner systems refer to the use of air to cool the compressor and the condenser coil. These split systems usually have an evaporator cooling coil installed indoors to work along with the blower and duct system which may also be sitting atop a heating furnace. The outside half of the equipment contains the compressor and condenser coil. Refrigerant moving through the system as a gas or liquid moves heat from inside the building (at the evaporator coil in an air handler) to outside the building at the condenser unit's condensing coil. Water cooled A/C systems work in a way similar to the system listed above, but use water as a chiller to remove heat from the high temperature gas in the compressor and condenser unit. Evaporative coolers, also called "swamp coolers", depend on the evaporation of water to cool indoor air, rather than the transfer of refrigerant through cooling coils. Cooling towers, swamp coolers, and even a simple window fan blowing air across a pan of water and into a room are types of evaporative cooling systems. Swamp cooler systems may use less energy than a refrigerant-gas and compressor type air conditioner but they'll only work where the ambient humidity is low enough to make it easy to evaporate water, such as in Arizona and other areas of the Southwest and Mexico. Gas Chiller A/C Systems operate by the same principles as the above systems, but they use heat to change the refrigerant gas states rather than compression and expansion by a compressor motor. Some refrigerators, including ones used in R/V's also operate on this principle, as they can cool without requiring electricity to operate a compressor motor. Ammonia was the traditional gas used for this type of system. References Types of HVAC Systems: www.staffordheatingandair.com/systems.htm Types of Air Conditioning Systems: http://www.brighthub.com/engineering/mechanical/articles/897.aspx Air Conditioning Heating Systems: http://highperformancehvac.com/ E-How: Types of HVAC Systems: http://www.ehow.com/facts_5009377_types-hvac-systems.html Residential Duct Systems: http://www.toolbase.org/PDF/DesignGuides/residential_duct_systems.pdf