HVAC PART 8 SECTION 3 in NBC

1. AIRCONDITIONING,HEATINGAND
MECHANICALVENTILATION

2. Introduction
• This code deals with the planning, selection,
design considerations and installation of air
conditioning, heating and mechanical ventilation
system.
• Computerized weather data is now available and
has been included for around 60 locations across
the country covering all 5 climatic zones.
• Since the last revision of the Code in 2005, there
has seen tremendous emphasis on energy
conservation to meet the challenges posed by the
climatic change.

3. Scope
• This code aims to ensure an air conditioning,
heating and mechanical ventilation system by
managing air temperature, humidity, indoor air
quality.
• Distribution of conditional air for specific use.
• Occupancy of built space while giving
consideration to minimizing energy consumption
and other resources.

4. Refrigerants
Refrigerants are mainly classified as follows:-
• Based on toxicity they are classified into two types namely
class A, class B.
• Based on flammability they are classified into four types
namely class 1, class 2L, class 2, class 3.
Matrix Diagram of Safety Group Classification
System of refregirents

5. Planning
The planning includes the following considerations:
• Fundamental requirements.
• Design considerations.
• Equipment room for central air conditioning plant.
• Pipe shafts.
• Supply air ducts and return air ducts.
• Cooling tower.
• Energy efficiency.(Designers shall aim for energy
efficiency in buildings with the right blend of passive
and active design strategies )

6. Outdoor design conditions
• The outdoor design considerations are taken from table 2. For
cities not provided in the table interpolations are used
considering the climatic conditions.
• For normal comfort conditions, values under 1% column
should be used for cooling loads and 99% percent for heating
loads.
• For critical applications, values under 0.4% column should be
considered for cooling loads and 99.6% column for heating
loads.

7. Outdoor Design conditions

8. Indoor design conditions
• One of the primary objective of designing indoor
environment is to ensure thermal comfort of all occupants.
• HVAC is employed for same purpose only though building
design is limited.
• The following are the 4 environmental parameters which
are controlled by HVAC systems and are also controlled by it
1.Air temperature(C0).
2.Radiant temperature (C0).
3.Air speed (m/s).
4.Relative humidity (percent).
• The following are the 2 additional parameters which affect
thermal comfort but are not controllable
1.Activity rate (W/m2).
2.Clothing insulation (m2.K/W).

9. Design of air conditioning
• General.
• Design considerations.
• Factors to be considered for different applications.

10. Refrigeration for cold stores
• Key elements and components of cold room.
• Typical design inputs for a standard cold room.
• Importance of heat loads.
• Considerations for cold room selections.
• Installation and maintenance of cold room.
• Cold room safety.

11. Heating
• Various heating equipment / systems are:
• Hot water heated coils.
• Electrical heating.
• Solar water heating systems.
• Condenser heat recovery system.
• Heat pump.
• Ground source Heat pump.

12. Mechanical Ventilation
Tunnel ventilation system Underground car park ventilation system
Commercial kitchen ventilation.Industrial ventilation system

13. Installation of HVAC systems
• Installation of air conditioning systems.
• Installation of split air conditioners.
• Installation if VRF systems.
• Installation of mechanical ventilation system.

14. Symbols, units , color codes and
identification of services
• Color code is required for easy identification of various items
in an air conditioning installation for correct identification and
interpretation.