This presentation is about the fundamental principles of refrigeration and air conditioning

1. HVAC/REFRIGERATION
CONTROLS
PRINCIPLES OF
REFRIGERATION AND
AIR CONDITIONING/HVAC

2. REFRIGERATION

46. How air conditioners work?
• Air conditioners are one part of a central heating and central cooling
system that draws heat energy from outside of the home and
transfers it.
• Simply put, the air conditioner in both a house and business is a
central heating and cooling system that provides cool air through the
sheet metal ductwork by providing via a process that draws out the
warm air inside, removing its heat, which is replaced by the cooler air.
• The entire process of making the air in your property a comfortable
temperature is based on a very simple scientific principle, and the rest
is achieved by mechanical means.

47. • Your air conditioning unit uses chemicals that convert from gas to
liquid and back again quickly. These chemicals transfer the heat from
the air inside your property to the outside air.

48. • The AC unit has three key parts. These are the compressor, the
condenser, and the evaporator. Your unit’s compressor and condenser
are typically located in the outside part of the air conditioning system.
Inside the house is where you will find the evaporator.
• The cooling fluid reaches the compressor as a low-pressure gas. The
compressor squeezes this gas/fluid, and the molecules in the liquid
are packed closer together. The closer the compressor forces these
molecules together, the higher the temperature and energy rise.

49. How Your Air Conditioner Removes Hot Air & Blows
Cold Air
• This working fluid exits the compressor as a high-pressure, hot gas, and it
moves to the condenser. The outside unit of an air conditioning system has
metal fins all around the housing. These fins work like the radiator on a
vehicle, and they help dissipate heat more quickly.
• When the fluid leaves the condenser, it is much cooler. It’s also changed
from a gas to liquid because of the high pressure. The fluid makes its way
into the evaporator through a minuscule, narrow hole and when the liquid
reaches the other side of this passage, its pressure drops. When this
happens, the fluid begins to evaporate to gas.
• As this occurs, the heat is extracted from the surrounding air. This heat is
required to separate the molecules of the liquid into a gas. The metal fins on
the evaporator also help exchange thermal energy with the surrounding air.

50. • When the refrigerant leaves the evaporator, it is once again a low-pressure,
chilled gas. The process starts all over when it goes back to the compressor. There
is a fan that’s connected to the evaporator, and it circulates air around the inside
of the property and across the fins of the evaporator.
• The air conditioner sucks air into the ducts through a vent. This air is used to cool
gas in the evaporator, and as the heat is removed from the air, it’s cooled. Ducts
then blow air back into the house.
• This process continues until the inside air of your home or business reaches the
desired temperature. When the thermostat senses that the interior temperature
is at the desired level, it shuts the air conditioner off. When the room heats up
again, the thermostat turns the air conditioner back on until the preferred
ambient temperature is achieved again.
•

63. CONDENSER

65. EVAPORATOR