1. BUILDIND MANAGEMENT
HVAC
To know working principle , operation and maintenance of HVAC (Syllabus)
PRESENTED BY-
Divya.S
Manasa Ravikumar
Nagaraksha
Rohith.S
2. BUILDING MANAGEMENT
Heating, Ventilation and Air-Conditioning Systems
I SEMESTER- GROUP 1
What Is a HVAC ?
HVAC is an acronym that stands for Heating, Ventilation, and Air Conditioning
Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the
temperature, humidity and purity of air in an enclosed space to provide thermal comfort and acceptable indoor
air quality.
Fresh Conditioned air.
INLET OUTLET
PROVISIONS / SOLUTIONS:
• AC Unit
• Ducting layout + inlet Grill.
• AHU (Air handling unit).
• CHWS – Chilled water supply duct.
• Cooling Towers
StaleAir/ odour.
PROVISIONS / SOLUTIONS:
• Exhaust Ducting layout + Grill
• EA(Exhaust air) Duct.
3. BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
Heating, Ventilation and Air-Conditioning Systems
ADVANTAGES DISTADVANTAGES
Rapid cooling: The air conditioning system can
lower the indoor temperature in a short time,
providing a convenient and comfortable
environment for users.
Humidity control: It can not only regulate indoor
temperature but also control humidity to make
users feel more comfortable.
Air purification: It can filter air and also remove
indoor pollutants to provide a cleaner indoor
environment.
Space saving: It can be installed directly on the
wall or ceiling without occupying the floor space.
High energy consumption: Since air conditioners
require mechanical and electrical power to
work, their energy consumption is on the high
side, and using air conditioners will increase
energy consumption a lot.
Harmful to health: Excessive use of air
conditioning can lead to a significant reduction in
indoor air humidity, which dries out the skin and
can be potentially harmful to health
.
High cost: The air conditioning system is costly
and requires professional installation, and then the
cost of post-maintenance can be high.
4. FUNCTION OF HVAC SYSTEM
•To control temperature.
•To control humidity
•To prevent cross contamination
•To maintain proper air movement
All of these elements collectively to serve to maintain a comfortable environment within a enclosed space.
Working principles include the ability to move large volumes of air, the use of convection and radiation for
heating and cooling, and components that help regulate humidity levels. The movement of air is achieved
by using fans which can push cold or hot air into space as needed.
WORKING PRINCIPLES OF HVAC SYSTEM
BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
5. WORKING OF HVAC SYSTEM
OR
WHAT ARE THE COMPONENTS THAT MAKE UPAN HVAC SYSTEM
The goal of your HVAC system is to make your ideal home comfort circumstances become a
reality. To do this, a complete system must be built from a combination of an air conditioner,
furnace, air handler, ductwork, thermostat and even some other units like a humidifier or air
purifier.
•Air Conditioner - Cools your home by removing heat and humidity from inside and transferring it outside.
•Heat Pump - Contrary to their name, a heat pump can both heat and cool your home. They use refrigerant
to absorb, transport, and release heat, and they can reverse the flow of that refrigerant depending on if you
need heating or cooling.
•Furnace - Creates heat by burning a fuel source like natural gas or propane. The heat they create is then
distributed throughout your home, in order to increase the indoor temperature.
•Air Handler - Circulate both warm and cool air formed by other HVAC units throughout your entire
home, in order to reach your desired temperature in every room.
•Ductwork - is a system of pipes, also known as ducts, that carry and distribute air from units like your
furnace, air conditioner, and heat pump.
•Thermostat - The thermostat, located inside your home, allows used to control your indoor temperature.
When you change the temperature on your thermostat, it signals to the rest of your HVAC system your
home needs to be warmer or cooler.
BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
6. DESIRABLE TEMPERATURE
What Is Room Temperature?
The range of air temperature that is most commonly comfortable to people when they are indoors. However,
things like air circulation, humidity, and other factors can impact what temperature is most comfortable for
people. On top of that, people differ physiologically and have different preferences.
Room temperature is defined differently in different places. It generally refers to a range somewhere
between 68 and 74 degrees Fahrenheit/ 20 degrees and 23 degree
For normal comfort conditions, relative humidity (RH) values between 40 percent and 70 percent are
acceptable.
BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
7. IS : 659 - 1964
This code covers the safe design, construction, installation, operation,and inspection of air conditioning
equipment, inside design conditions,mechanical equipment and refrigerant piping, duct work for air, electric
wiring and fire protection.
TERMINOLOGY
Air Conditioning :The process of treating air so as to control simultaneously its temperature, humidity,
cleanliness and distribution to meet the requirements of the conditioned space.
Positive Ventilation : The introduction of outside air by means of a fan or blower or any other mechanical device.
The amount of positive ventilation can always be easily measured, because it is exclusively what is drawn by the
mechanical device from outside.
Re-circulated Air : Air which is returned to the plant from the conditioned space but which is not re-treated.
Re-heating :The process by which air, which has been cooled down in order to condense out part of the moisture
it contains, is heated again in order to raise its temperature to a suitable level.
Return Air:The air which is returned from the conditioned space to the plant for re-treatment.
Supply and Return Air Grilles :The fittings which are fixed at the openings through which air is delivered into
and returned from the air conditioned enclosure by an air conditioning plant or unit.
Temperature, Dry Bulb : The temperature read by a thermometer placed in such a way that errors due to
radiation are eliminated
Temperature, Wet Bulb : The steady temperature finally read on a thermometer having its bulb covered with
gauze or muslin moistened with distilled water in an air stream of not less than 4.5 metres per second.
BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
8. IS : 659 - 1964
VENTILATION
Only positive ventilation methods shall be adopted for ventilation of
air conditioned enclosures.
Minimum Ventilation
The total minimum outside fresh air introduced into an enclosure by an air conditioning
plant or unit by the method specified in 3.1 shall be related to the number of occupants in the enclosure at any
time, whether they are smokers or non-smokers and to the cubic contents of the enclosed space in the manner
specified in Table 1.
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9. IS : 659 - 1964
BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
10. IS : 659 - 1964
INSIDE DESIGN CONDITIONS
For air conditioning systems other than comfort air conditioning, design conditions as required by the processes
involved may be adopted.
For comfort air conditioning dry bulb and wet bulb temperatures
may be adopted as given in Table 2 for summer and in Table 3 for winter.
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11. IS : 659 - 1964
BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
17. NBC
BUILDING MANAGEMENT MARCH-1SEM-GROUP 1
For ductwork services and insulation, the color triangle may be provided. The size of the triangle will depend on the
size of the duct and viewing distance but the minimum size should not be less than 150 mm length per side. The
color for various ductwork services shall be as given below:
18. IS : 659 - 1964
MECHANICAL EQUIPMENTS
• The design and installation of compressors, condensers, evaporators, piping and other apparatus forming a part
of the refrigerating system of an air conditioning installation shall conform to the requirements of IS : 660 -
1963*.
• Where steam is used for heating or re-heating air for air conditioning by direct contact with a heating coil, the
pressure of steam used shall not exceed 3.5 kg/cm2.
• Any heating coils used in an air conditioning system shall withstand a hydrostatic pressure five times the
working pressure of steam for a period of one minute without failure or leakage.
• All boilers used in producing steam for heating purposes shall satisfy the requirements of the Indian Boilers
Act and other Central or State Acts and regulations in the matter of the use of boilers.
• No machinery with moving parts shall be placed inside an operation theatre.
DUCT WORK
All metal duct work shall conform to the requirements of IS : 655 -1963†.
ELECTRICAL WIRING INCLUDING FIRE PRECAUTIONS
Conformity with Indian Electricity Act, Rules and Standards
All electrical work in connection with the wiring and installation of electrical equipment shall be carried out in
accordance with the provisions of Indian Electricity Act and Rules thereunder and shall also comply with
the provisions of IS : 732-1963‡ and IS : 2274-1963.
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