BASIC INFORMATION OF HVAC

HVAC BRIEF DESCRIPTION          

                                  

1. HVAC Systems Control the indoor environment (temperature) Humidity airflow and air filtering 
2. Mechanical intervention to condition the air to a preferred temperature and relative humidity.

HUMAN COMFORT

1. Conditions at which most people are likely to feel Comfortable most of the time

2. Also Called as thermal Comfort 

3. Temperature 

    Summer - 78 F (25c)    winter - 68 F (20c) 

    Relative Humidity : 30%  60% 

By using HVAC System

• Temperature can be raised or lowered

  • Humidity can be Raised or Lowered maintain       proper  filtration of air 

•   Proper air move ment 
•  Out side air can be added and removed 
•  To hold the air contamination with in acceptable  limits 

Application of HVAC System 

1. Residential 
2. Commercial 
3. Industrial 
4. Educational 
5. Hospital 
6. Mall of etc....

Heat Transfer

Heat flows Due to

Conduction Convection and Radiation 

1. Conduction is transfer of heat through solid matters 
2. Convection is transfer of heat through liquid 
3.  Radiation is transfer of heat through gas/air 

   Degree Temperature 

1. Degree centigrade - c 

Metric  Standrd international (SI unit)

2. Degree Fahren heit -F 

English :- Inch per pound (IPunit)

              'C= (F-32)×5/9

              'F= ('c×9/5) 32 

Major Components of air conditioning system

      

                                      Compressor 

Compressor

1. This Component is the heart of the system 
2.  Pump refrigerant and oil through system 
3. Separates the high pressure side of the system from low pressure side 
4. If it's fail no cooling is takes place 

Condenser

                       

                             Condenser

Condenser coil is what gets rid of the heat in the system can be water cooled (Located inside,Cooled with cooling tower water) or air cooled (Located in out side open to atmosphere)type Traps dirt and require preventive maintenance and cleaning

EVAPORATOR

                                      EVAPORATOR

Provide cooled air to the space,Located after the system air filters,Removes moisture from air 

Traps inside dirt's/dust infilters,so require preventive maintenance 

EVAPORATOR FAN

EVAPORATOR FAN

Located behind or in front of evaporator coil Draw ambient and mix air across evaporator coil

THERMAL EXPANSION VALVE 

1. Located at the evaporator coil
2. Provide the correct amount of refrigerant to the evaporator coil for proper cooling 
3. Separates the high pressure side of the system from low pressure side
4. Failure could cause compressor failure and loss of cooling capacity