Physics Dissection Paper: Air Conditioning Technology (Essay Sample)

PHYSICS DISSECTION PAPER: AIR CONDITIONING
Name of Student
Institution
Definition of an Air Conditioning System:
It is a system designed to lower the temperature of air, dehumidify, filter, and circulate the air to create a comfortable room atmosphere. There are several systems, though we shall study the working principle only, and not the types.
Components of Air Conditioning System
The Coils
Two coils, one on each side of the house, inside and outside. Something cold, the refrigerant is channelled through the coil inside the house before we inject warm air across the coil. This allows the coil to absorb heat from the house air.
Refrigerant
A nontoxic, noncorrosive, and non-flammable Freon 12 or Freon 22 is passed through the coil lumen. Freon does run in a loop. It passes via the indoor coil, via copper pipe to the outdoors, through the coil on the outdoor, and re-enters the indoor coil via a different pipe.
See figure below.
As the Freon in the coil turns from liquid to gaseous state, it absorbs the heat from the air in the building. The gaseous Freon does leave coil warmer than the incoming liquid.
Let us assume that a cold low-pressure liquid is passed across the coil – evaporator coil – inside the building, the air of the building at 75°F blows across the refrigerant before moving out of the coil at 55°F. The cold Freon, liquid, which entered the evaporator coil exits as a gas at low pressure. The cold gas at low pressure goes outside and compresses into a hot gas at high pressure. Then the hot gas is channelled through the condenser coil – at 85℉ - and the outdoor air blows across it. The hot gas will dissipate some heat into the outdoor air, causing the hot gas to condense back into a warm liquid. To labour my point, the outdoor air can enter the evaporator coil at 85℉and leave at 100℉. The warm liquid is take back into the building where it is expanded. This causes a significant temperature drop, which in turn, condenses the air into a cold liquid at low pressure. That is the basic principle of an air conditioner.
The use of Psychometric Charts is the best way to solve air conditioning mathematical problems.
KEY
Points 1 and 2 represent the moist air from the air conditioning system entering the building, and the moist air leaving the building respectively.
t1 =>temperature of moist air from the air conditioning system entering the building
t2=> temperature of moist air from the air conditioning system leaving the building
ma=> mass flow rate of refrigirant in kg/sec
ω1=> specific humidity of moist air from the air conditioning system entering the
building
ω2=> specific humidity of moist air from the air conditioning system entering the
building
h1=> specific enthalpy of moist air from the air conditioning system entering the
building
h2=> specific enthalpy of moist air from the air conditioning system leaving the
building
tx, ωx, and hx , are the intermediate values of temperature, specific humidity and specific enthalpy
in that order
Cpma=> specific heat capacity of the refrigerant ie Freon