Good day,
Today i would be explaining about HVAC systems which are used in most of the buildings, Many of the experienced engineers are unaware of the working principle of basic cooling system.
Firstly i will be explaining about the Basics of cooling system,to know more about cooling system one should be aware of the following four terms.(we will be using a window AC as an example to explain below terms)
The above illustration can be best explained by below line diagram.
Fig:01 - Cooling Cycle.
Source (http://www.constructionknowledge.net/mechanical/mechanical_hvac.php)
The red line indicates hot and the blue cool. Step by step explanation of the above diagram is as below
1) Firstly the compressor which has an intake of Low pressure gas and compress it. As we know that any gas which is compressed is heated up by having High pressure.
2) The Hot vapour and high pressure gas is then passed through a condenser. A condenser is which make gas into liquid. Thus making high pressure and High temperature liquid.
3) when the high temperature liquid passes through expansion valve a sudden decrease in temperature takes place.
4) the same Cold Liquid with low pressure is passed though a evaporator which decapitates the heat to another medium generally which is transferred to an air medium.
This makes the a cycle to appear and this cycle is repeated to have a constant flow of cool air.
Generally the refrigerant being used is ammonia.
Fig:02 Window AC Parts
This shows a typical Window AC with its parts.Fig-01 shows Red line and Blue line, Red line is the
Hot line which is generally kept outside the window and the Blue inside in the same unit. Thus when we
separate this we called it as split Unit.
source:http://home.howstuffworks.com/ac3.htm
know we move a step ahead as we know the basics of cooling systems.
The above traditional process require energy for operation, it makes more costlier to use this system
in buildings and hence a new era came which uses HVAC system, the concept and the basics remains same
but the layout changes appear in HVAC system which increases the efficiency and reduces cost/maintenance/ space.
HVAC systems are being used in almost all major projects nowadays, since the efficiency is much higher compared to other systems. The same principle is used here too but instead of having several units each for a confined area, this system uses a single source for entire building with dampers to regulate each confined area.
This concept is best explained by a line diagram as below
Each room is provided with a thermostat( temperature controller) which defines the temperature of the room, Tenants can have there comfortable temperatures by opening and closing the dampers.
Further the whole setup can be divided into two parts
1) Air side
2) Water side
Air side is the evaporator part which uses the Duct as transfer of Air to the required area.
Water side of the system needs cool water to be circulated.
Either we can control the inflow air or we can control the inflow of cooling liquid.
Further in depth of HVAC systems will be posted in a new post.
Today i would be explaining about HVAC systems which are used in most of the buildings, Many of the experienced engineers are unaware of the working principle of basic cooling system.
Firstly i will be explaining about the Basics of cooling system,to know more about cooling system one should be aware of the following four terms.(we will be using a window AC as an example to explain below terms)
1) Compressor - which compresses the air ( High pressure and Hot Air)
2) Condensor - Converts Air into Liquid (High pressure & Hot Liquid)
3) Expansion valve - Sprays out nozzle ( Low pressure & Cold Liquid)
4) Evaporator - Transfer of Heat (Low pressure & Warm air)
The above illustration can be best explained by below line diagram.
Fig:01 - Cooling Cycle.
Source (http://www.constructionknowledge.net/mechanical/mechanical_hvac.php)
The red line indicates hot and the blue cool. Step by step explanation of the above diagram is as below
1) Firstly the compressor which has an intake of Low pressure gas and compress it. As we know that any gas which is compressed is heated up by having High pressure.
2) The Hot vapour and high pressure gas is then passed through a condenser. A condenser is which make gas into liquid. Thus making high pressure and High temperature liquid.
3) when the high temperature liquid passes through expansion valve a sudden decrease in temperature takes place.
4) the same Cold Liquid with low pressure is passed though a evaporator which decapitates the heat to another medium generally which is transferred to an air medium.
This makes the a cycle to appear and this cycle is repeated to have a constant flow of cool air.
Generally the refrigerant being used is ammonia.
Fig:02 Window AC Parts
This shows a typical Window AC with its parts.Fig-01 shows Red line and Blue line, Red line is the
Hot line which is generally kept outside the window and the Blue inside in the same unit. Thus when we
separate this we called it as split Unit.
source:http://home.howstuffworks.com/ac3.htm
know we move a step ahead as we know the basics of cooling systems.
The above traditional process require energy for operation, it makes more costlier to use this system
in buildings and hence a new era came which uses HVAC system, the concept and the basics remains same
but the layout changes appear in HVAC system which increases the efficiency and reduces cost/maintenance/ space.
HVAC systems are being used in almost all major projects nowadays, since the efficiency is much higher compared to other systems. The same principle is used here too but instead of having several units each for a confined area, this system uses a single source for entire building with dampers to regulate each confined area.
This concept is best explained by a line diagram as below
Each room is provided with a thermostat( temperature controller) which defines the temperature of the room, Tenants can have there comfortable temperatures by opening and closing the dampers.
Further the whole setup can be divided into two parts
1) Air side
2) Water side
Air side is the evaporator part which uses the Duct as transfer of Air to the required area.
Water side of the system needs cool water to be circulated.
Either we can control the inflow air or we can control the inflow of cooling liquid.
Further in depth of HVAC systems will be posted in a new post.