3. HVAC brief description:
• HVAC stands for heating, ventilation, and air conditioning.
• HVAC systems control the ambient environment (temperature,
humidity, air flow, and air filtering)
• Mechanical intervention to condition air to a preferred temperature
and relative humidity.
4. By HVAC System:
• Temperature can be Raised or Lowered
• Humidity can be Raised or Lowered
• Filtration can Occur
• Proper Air Movement
• Outside Air can be Added and Removed
• To hold the air contamination within acceptable limits.
5. Application of HVAC system:
• Residential
• Commercial
• Industrial
• Educational
• Pharmaceuticals
• Hospitals
• Malls/Offices
• And many more….
8. Major Component of Air conditioning system:
• Compressor:
This Component is the heart of the system.
Pump refrigerant & oil through system.
Separates the high pressure side of the system from low pressure side.
If its fail, no cooling is takes place.
• 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
outside open to atmosphere) type.
Traps dirt & require preventive maintenance & cleaning.
9. • Evaporator:
Provide cooled air to the space.
Located after the system air filters.
Removes moisture from air(condensate).
Traps inside dirt's/dust in filters, so require preventive maintenance.
• Evaporator fan:
Located behind condenser coil.
Draw ambient air across condenser coil.
• Thermal expansion valve:
Located at the evaporator coil.
Provide the correct amount of refrigeranet to the evaporator coil for proper cooling..
Separates the high pressure side of the system from low pressure side.
Failure could cause compressore failure & loss of cooling capacity.
10. How moisture removed by AC:
• As hot air is blown over the evaporator coils in your air conditioning
system, moisture is removed from the air as it condenses. The
condensate is the collected in a pan and drained from the system.
• Damp, humid air does maintain heat more than dry air. That is why,
during the air conditioning process, your AC removes humidity from
the air as it operates. As hot air is blown over the evaporator coils in
your air conditioning system, moisture is removed from the air as it
condenses
11. Unit of Refrigeration:
• TR: 1 TR is amount of heat to be extracted from the atmosphere for
Melting one metric ton of ice in 24 Hrs.
• 1TR: 12000 btu/hr
• 1TR: 3000kcal/hr
=50 kcal/min
13. Steps for deciding the system:
• Calculation of cooling load requirement
• Selection of techno-economical system
• Equipment selection.
• Designing Air distribution system
• Designing Water distribution system
• Designing Refrigerant distribution system
• Evaluation of system to be used.
14. Imp. Factors to be considering during Cooling
load requirement:
• Building detailed layout.
• Use of Space
• Physical dimension of space
• Inside room design condition
• Filtration level required
• Ambient condition
• Glass area exposed to sun
• Occupancy
• Lighting load
• Equipment load
• Fresh air requirement
• Infiltration of outside air
15. Factor affecting system selection:
• Budget of Client
• Need/Requirement of client
• Use of Space
• Outside condition
• Aesthetic
• Floor layout
• Location and dimension of beam/Column
• Power availability
• Space availability
• And many more…
17. Various AC system:
• Split AC
• Cassette AC
• Window AC
• Ductable AC
• Package AC
• VRF System
• Chiller System
• Dx-System
18. Split AC
A split air conditioner consists of two main parts: the outdoor unit and the indoor unit. The outdoor
unit is installed on or near the wall outside of the room or space that you wish to cool. The unit
houses the compressor, condenser coil and the expansion coil or capillary tubing.
Available capacity: 1 TR to 3 TR
19. Cassette AC
A ceiling- mounted or suspended air conditioner, for when space is limited, because there is no available
walls to mount a split system or where there is limited ceiling space for a ducted system.
Available Capacity: 1 TR to 4 TR
20. Window AC
The term “Window AC" describes a type of AC in which a single unit contains all the components of the
air conditioning unit; it is installed in a window of the room.
Available capacity: 1 TR to 2.5 TR
21. Ductable AC
It is one in which you can run ducting form the inside cooling unit to locations you need a cooling outlet.
Available Capacity: 1 TR to 18.5 TR single unit
22. Package AC
In the packaged air conditioners all the important components of the air conditioners are enclosed in a
single casing like window AC.
Available capacity: 3 TR to 25 TR and more.
23. VRF System:
VRF stand for variable refrigerant flow.
In the VRF system, multiple indoor units of multiple room/area/floors are combined in single outdoor unit which shall be
placed in open to atmosphere.
Available capacity:6 Hp to 30 Hp (single ODU) and connected upto 100 Hp. (Its changes from company to company)
Maximum distance from IDU to ODU : 200 mtr (approx., its changes from company to company)
25. Dx- System
A direct expansion air conditioning (DX) system uses a refrigerant vapour expansion/compression (RVEC)
cycle to directly cool the supply air to an occupied space. ... Expansion refers to the treatment of the
refrigerant (a valve reduces its pressure and temperature) prior to it entering the evaporator.
28. What is AHU???
• An air handler is a device used to regulate and circulate air as part of
a heating, ventilating, and air-conditioning (HVAC) system.
• Air Handling Unit is a large metal box containing a blower, heating
and/or cooling elements, filter racks or chambers, sound attenuators,
and dampers.
• Air handlers usually connect to ductwork that distributes the
conditioned air through the building, and returns it to the AHU.
Sometimes AHUs discharge (supply) and admit (return) air directly to
and from the space served, without ductwork.
35. What is ventilation…???
• Ventilation moves outdoor air into a building or a room, and
distributes the air within the building or room. The general purpose
of ventilation in buildings is to provide healthy air for breathing by
both diluting the pollutants originating in the building and removing
the pollutants from it.
36. Elements of ventilation.....!!!
i)Ventilation rate:
The amount of outdoor air that is provided into the space, and
the quality of the outdoor air.
ii)Airflow direction:
The overall airflow direction in a building, which should be from
clean zones to dirty zones.
iii)Air distribution or airflow pattern:
The external air should be delivered to each part of the space in
an efficient manner and the airborne pollutants generated in
each part of the space should also be removed in an efficient
manner.
37. Types of Ventilation System:
• Forced Ventilation:
A building ventilation system that uses powered fans or blowers to provide fresh air to
rooms when the natural forces of air pressure and gravity are not enough to circulate air
through a building.
• Natural ventilation:
Natural ventilation is the process of supplying air to and removing air from an indoor space
without using mechanical systems. It refers to the flow of external air to an indoor space as
a result of pressure differences arising from natural forces.
• Hybrid ventilation:
Hybrid (mixed-mode) ventilation relies on natural driving forces to provide the desired
(design) flow rate. It uses mechanical ventilation when the natural ventilation flow rate is
too low
38. Various Forced Ventilation System:
• Evaporative Cooling Unit
• Fresh Air Fan unit
• Exhaust Unit
• Exhaust Fans
• And many more….
39. What is Evaporative Cooling Unit…???
• An evaporative cooler is a device that cools air through
the evaporation of water.
• Evaporative cooling works by exploiting water's large enthalpy of
vaporization.
• The temperature of dry air can be dropped significantly through the
phase transition of liquid water to water vapour (evaporation). This
can cool air using much less energy than refrigeration.
• The cooling potential for evaporative cooling is dependent on the wet
bulb depression, the difference between dry-bulb temperature
and wet-bulb temperature.
42. Centrifugal Fan
• Centrifugal fans use the kinetic energy of the impeller to increase the
volume of the air stream, which in turn moves them against the
resistance caused by ducts, dampers and other components.
• Centrifugal fans displace air radially, changing the direction (typically
by 90°) of the airflow. They are sturdy, quiet, reliable, and capable of
operating over a wide range of conditions.
• Types of Centrifugal fans:
Radial Curved
Forward Curved
Backward Curved
43. Axial Fan:
• The blades of the axial flow fans force air to move parallel to the
shaft about which the blades rotate.
• Axial fans are typically used for exhausting dirty air or fumes from
processes (such as paint spray booths), supplying fresh air, and
general spot cooling of people, rooms or machinery.
• Types of Axial Fans:
Tube axial
Vane axial
Propeller fans
