6.B] Write a short note on Centralised Air Conditioning and enumerate how it is differed from the comfort room air conditioner
Answer:
Central air conditioning (or central A/C) is a system in which air is cooled at a central location and distributed to and from rooms by one or more fans and ductwork. The work of the air conditioner compressor is what makes the whole process of air conditioning possible. The compression of the refrigerant gas enables it to discharge heat out of the house, which is how the cool air is created.
The compressor (which is controlled by the thermostat) is the “heart” of the system. The compressor acts as the pump, causing the refrigerant to flow through the system. Its job is to draw in a low pressure, low temperature, refrigerant in a gaseous state and by compressing this gas, raise the pressure and temperature of the refrigerant. This high pressure, high temperature gas then flows to the condenser coil.
The condenser coil is a series of piping with a fan that draws outside air across the coil. As the refrigerant passes through the condenser coil and the cooler outside air passes across the coil, the air absorbs heat from the refrigerant, which causes the refrigerant to condense from a gas to a liquid state. The high-pressure, high-temperature liquid then reaches the expansion valve.
The expansion valve is the “brain” of the system. By sensing the temperature of the evaporator, or cooling coil, it allows liquid to pass through a very small opening, which causes the refrigerant to expand to a low-pressure, low-temperature gas. This “cold” refrigerant flows to the evaporator.
The evaporator coil is a series of piping connected to a furnace or air handler that blows indoor air across it, causing the coil to absorb heat from the air. The cooled air is then delivered to the house through ducting. The refrigerant then flows back to the compressor where the cycle starts over again.
•Comfort air conditioning is the controlling of humidity and temperature of air to give maximum comfort to the human beings.
•Industrial air conditioning is required in controlling the humidity and temperature in processing and manufacturing industries.