Mahatma Gandhi Mission’s
College of Engineering and Technology.
Noida, U.P., India
Technical seminar on
HEATING VENTILATION AND AIR CONDTIONING
Under the guidance of Prepared by
MR. ABHIJIT KULKARNI Krishan Kumar
• Introduction to HVAC
• History of HVAC
• Need of HVAC
• Air conditioning process
• Types of installation
• Recent Development in HVAC
• Advantages & Disadvantages
• Applications of HVAC
WHAT IS HVAC?
• Heating, Ventilation, and Air Conditioning
WHAT DOES IT DO?
• HVAC is a basic requirement for your indoor air
quality, what you breathe, temperature, humidity --
in your house.
• So when you hear the term "HVAC" it means the
entire air system of your home.
HISTORY OF HVAC
• IN 1851 Dr John Gorrie was granted U.S. Patent for
• In 1880 refrigeration became available for industrial
purpose. Initially two major uses –freezing meat for
transport and making ice.
• Early 1990-new initiative to keep building cool for
• 1902 cooling the New York stock exchange-one of
the first comfort cooling system.
NEED OF HVAC SYSTEM
• Improvement of the air quality
• Moisture regulation
• Maintenance of the constant temperature throughout
• Energy conservation
• Heat exchanger
• Air Conditioning Unit
• Evaporator Coils
• Condensing Unit
• As part of the HVAC, the furnace
heats the air that circulates in the
• The quality of air in the home can
be influenced by how often you
change the air filter on your unit.
• Usually the Air Conditioner is
outside, and the furnace is inside
• The HVAC uses the same venting
system for both.
WHAT ARE BTU’S AND EER’S
• BTU or British Thermal Units, are the amount of heat
required to raise the temp. of one pound of water, 1
degree Fahrenheit. 1 ton= 12,000BTU.
• EER is Energy Efficiency Rating and tells you the
BTU rating over the wattage. The higher the EER, the
better the energy efficiency, but it will probably cost
CONVECTION-Collective movement of groups
of molecules within fluids , through diffusion
CONDUCTION -Transfer of internal energy by
microscopic diffusion and collisions of particles within a
body due to a temperature gradient.
RADIATION- Electromagnetic waves (EMR) travel
through a vacuum or through matter-containing media.
GENERATION OF HEAT
• Heaters exist for various types of fuel, including solid
fuels, liquids, and gases.
• Another type of heat source is electricity, typically
heating ribbons made of high resistance wire.
• This principle is also used for baseboard heaters and
• Electrical heaters are often used as backup or
supplemental heat for heat pump systems.
DISTRIBUTION OF HEAT
• WATER/STEAM -
• Piping is used to transport the heat to the rooms.
• Modern hot water boiler heating systems have a
circulator, which is a pump, to move hot water
through the distribution system .
• Warm air systems distribute heated air through duct
work systems of supply and return air through metal
or fiberglass ducts.
• Many systems use the same ducts to distribute air
cooled by an evaporator coil for air conditioning.
MECHANICAL OR FORCED-Provided
by an air handler and used to control indoor air
• Excess humidity, odours, and contaminants can often be
controlled via dilution or replacement with outside air.
• Kitchens and bathrooms
of a building with outside air without using fans
or other mechanical systems.
-reduces spread of diseases- tuberculosis, common cold.
• Effective mixing of ventilation air within space
• Net positive pressure in the southeast; exhaust from
• Provide clean outdoor air, avoid:
– loading docks
– exhaust vents
– plumbing stacks
– waste collection
– stagnant water
AIR CONDITIONING UNIT
An air conditioner is like a refrigerator without the
insulated box. It evaporates a refrigerant, like Freon, to
Most Air Conditioners Have:
– A compressor
– An expansion valve
– A hot coil (on the outside)
– A chilled coil (on the inside)
– Two fans
– A control unit
• Heart of the system, belt driven pump that fastened to engine.
• Responsible for compressing and transferring refrigerant.
• Very high volumetric efficiency (almost 98%)
• Lesser Noise and lighter compared to rotary compressor.
• Responsible for heat dissipation. The condenser is designed to
• Located in front of the radiator. Require good air flow when
system is in operation
• Plate fin type heat exchanger with micro channels used.Very
compact and better heat transfer capability.
• Hot compressed refrigerant vapour cools at constant pressure to
• Heat absorption component.
• Used remove heat from the inside of vehicle.
• Secondary benefit - dehumidification.
• Unconditioned air passes through a filter before entering the
• Plate-fin evaporator with micro channels used.
HEAT PUMP (HP)
• A machine or device that moves heat from one location (the
source) to another location (the mechanical work)
• Can produce heating or cooling by reversing the direction of heat
• Can be used in:
– Forced Air System
– HotWater System
– Radiant Heat System
TYPES OF INSTALLATION
• Window unit and packaged terminal
• Split system
• Mini Split System -typically produce 9,000–36,000
BTU(9,500–38,000 KJ) per hour of cooling.
• Central air conditioning
• Portable units-easily transported inside a home or
office ,capacities of about 5,000–60,000 BTU/h
USES OF AIR CONDITIONING
• Comfort application
• Domestic use
• Process application
Central Forced air system
Air handling system
• Hot water system
• Zone control system
• Radiant heat
CENTRAL FORCED AIR SYSTEM
• Most common HVAC system circulates air through or
around heating and cooling devices.
• A fan forces air into ducts
• Supply ducts transport conditioned air into building
through diffusers or supply registers
• Air is routed back to heating/cooling device through
AIR HANDLING UNIT(AHU)
• Device used to condition and circulate air as
part of an HVAC system
• Large metal box containing a blower, heating
or cooling elements, filter, and sound
• Connects to ductwork that distributes the
conditioned air through the building and
returns it to the AHU
AIR HANDLING UNIT (AHU)
• May need to supply heating, cooling, or both
• A furnace generates heat
– Fuel oil or natural gas
– Electric heating elements
• A refrigeration system absorbs heat
– Air conditioner
– Heat pump
AIR HANDLING UNIT (AHU)
• Smaller air handlers may contain a fuel-burning heater or a
refrigeration evaporator placed directly in the air stream
• Large commercial air handling units contain coils that circulate
– Boiler provides hot water or steam
– Chiller provides chilled water
AIR HANDLING UNIT (AHU)
Typical AHU components:
1. Supply duct
2. Fan compartment
3. Flexible connection
4. Heating and/or cooling coil
5. Filter compartment
6. Return and fresh air duct
HOT WATER SYSTEM
• Water heated in boiler and circulated through pipes to
• Requires plumbing rather than ductwork
ZONE CONTROL SYSTEM
• One heater and one thermostat per room
• No ductwork
• Often used in hotel rooms
• Supply heat directly to the floor, wall, or ceiling
• Hot water pipes or electric heating element runs through
• Dependent on radiant heat
– Heat transferred from hot surface to people and objects
RECENT DEVELOPMENT IN HVAC
Emerson Climate Technologies Launches E360
E360 provide a 360-degree view of commercial refrigeration
issues and advancements by addressing energy efficiency,
equipment reliability and safety, environmental protection, and
Serves as a means of centralizing all of this information and
providing us with the tools to interact with industry experts
and ultimately improve their operations.
RECENT DEVELOPMENT IN HVAC
DuPont Introduces New HFO Refrigerants for
Opteon XP40, Opteon XP44, and Opteon XP10.
Opteon XP40 is designed to effectively replace the refrigerant R-
Opteon XP10 is a lower GWP replacement for R-134a for
• Replacements for R-22 are HFC-134a, R-410a,
ADVANTAGES OF HVAC
1. Conserves Energy
2. Regulates Moisture
3. Air Quality Improvement.
DISADVANTAGES OF HVAC
• Initial installation cost is high.
• Primary disadvantage of ductless air
conditioners is their cost.
APPLICATIONS OF HVAC
• “Free cooling” during moderate temperatures (chiller
• Thermal storage—isolation of storage tank
• Water source heat pump pre cooler with isolation
• Heating potable hot water (instantaneous heater)
• Waste heat recovery from condenser water
• Proper system design accounts for building type and
size, layout, surrounding area, the nature of activities
taking place, the number of occupants, climate and
other factors, making each situation distinct.
• Optimizing system operation.
• Making and analysing certain key measurements is
essential for optimizing the HVAC system
2. www.saminfratech .com
4. Ventilation and Infiltration chapter, Fundamentals volume
of the ASHRAE Handbook, ASHRAE, Inc., Atlanta, GA, 2005