I.

Types and Applications passage of fan air to avoid burning of

ASHRAE - American Society of Heating hermetically sealed compressor coil.
Refrigerating & Air Conditioning Engineers
3. PACKAGED AIR CONDITIONER
Air Conditioning acc. to ashrae
- Process of treating air, simultaneously Types:
control temp, humidity, cleanliness A. Packaged Air Conditioner with Water Cooled
distribution to meet condition of given space Condenser
B. Packaged Air Conditioner with Air Cooled
TYPES Condenser
1. WINDOW AIR CONDITIONER
- Single rooms, all components enclosed in 4. CENTRAL AIR CONDITIONING PLANTS
single box, fitted in a window sill - slot made in A. Direct Expansion or DX Central Air
wall of room Conditioning Plant
a. Rigid Base B. Chilled Water Central Air Conditioning Plant
b. Partition Necessary action to operate equipment effectively:
c. Front Panel - Action to control temperature through
d. Louvers Thermostat and Controlling Valves
e. Refrigeration System - Humidity control through Thermostat and
i. Compressor Humidifier or Duct Heater
ii. Capillary Tubing - Action to Filter Air through Air filtering
iii. Evaporator device on Air handling equipment, Air
iv. Condenser purification including Air freshener
v. Air filter - Action to control air motion and circulation
vi. Accumulator to a given space through circulating fan and
modulating damper.
Refrigeration System of Air Conditioning Unit
A. Air Circulation System of the Window Air Purpose of Air Conditioning
Conditioner 1. Health and Human Comfort
a. Blower 2. Industrial Purpose and Special Air
b. Propeller Fan or the Condenser Fan Conditioning/Ventilation
c. Fan Motor
Factors Influencing Human Comfort
2. SPLIT AIR CONDITIONER 1. Human heat loss due to convection,
a. Indoor Unit evaporation and radiation in human bodies.
i. Evaporator Coil or The Cooling Coil 2. Insulating factor - discomfort due to improper
ii. Air Filter clothing
iii. Cooling Fan or Blower 3. Physiological factors - due to activity, age and
iv. Drain Pipe health
v. Louvers or Fins 4. Thermal comfort factors - due to varying air
Installation of Split Type AC temp and humidity, surface temp of body and
a. Indoor air motion on surface of human body.
- Located where air is distributed evenly, 5. Noise beyond acceptable limits causes
possibly above bed, should be easily discomfort.
accessible for maintenance
b. Outdoor I. Operative Surface Temperature: 20 − 26 𝐶
0

- Located in open space (pref. Terrace or 0

II. Humidity, must fall on dewpoint: 2 − 17 𝐶
hanging on wall), easily accessible for
maintenance, remove blockage from
 III. Air Velocity, at human breathing level: b. 4-pipe System
1 − 1. 8 𝑚 from finished floor level: up to Equipments used for transferring heat:
0. 25
𝑚
. - Fan coil unit
𝑠𝑒𝑐
- Convectors
- Radiators, etc.
II. Psychrometrics of Air Conditioning
3. Air-water systems
Processes Psychrometric Chart
4. Unitary refrigerant based systems
A. Dry bulb temperature lines
B. Specific humidity or moisture content lines
IV. Air Distribution System Design
C. Dew point temperature lines
Duct Design Objective:
D. Wet bulb temperature lines
1. Occupant comfort
E. Enthalpy (total heat) lines
2. Proper air distribution
F. Specific volume lines
3. Economical heating and cooling system
G. Relative humidity lines
operation
4. Economical duct installation
1. Adiabatic mixing of air streams
2. Sensible heating
A. SUPPLY DUCT SYSTEMS
3. Sensible cooling
a. Trunk and Branch Systems
4. Humidity and dehumidification
b. Spider System
5. Cooling and adiabatic humidification
c. Radial System
6. Cooling and humidification by water injection
d. Perimeter Loop System
7. Heating and humidification
B. RETURN DUCT SYSTEMS
8. Humidification by steam injection
C. MULTIPLE-ROOM RETURN SYSTEMS
D. CENTRAL RETURN SYSTEMS

III. Selection of Air Conditioning Systems

Duct Material
1. Sheet Metal
Criteria for the Selection of Suitable AC Systems,
2. Fiberglass Duct Board
depends on:
3. Flexible Nonmetallic Duct
1. Capacity, performance and spatial
requirements
Duct and Register Locations
2. Initial and running cots
3. Required system reliability and flexibility
Duct Design Method
4. Maintainability
5. Architectural constraints
Design Recommendations and Key Design
Elements
Classification of AC Systems
1. All air systems
Single duct
V. Cooling Load Calculations and Principles
a. Single duct, constant volume, single zone
TERMINOLOGY
systems
Space
b. Single duct, constant volume, multiple zone
Room
systems
Zone
c. Single duct, variable air volume (VAV)
Btu
systems
CLTD
Dual duct
Sensible Heat Gain
d. Dual duct, constant volume systems
Latent Heat Gain
e. Dual duct, variable air volume systems
Radiant Heat Gain
2. All water systems
Space Heat Gain
a. 2-pipe System
Space Cooling Load c. SCL
Space Heat Extraction Rate
Temperature, Dry bulb COMPUTER PROGRAMS
Temperature, Wet bulb 1. Elite CHVAC
Temperature, Dewpoint a. Calculation Method
Relative humidity b. Program Input
Thermal Transmittance/Heat Transfer c. Program Output
Coefficient (U-factor)
Thermal Resistance

SIZING AC SYSTEM
1. Heating Load vs Cooling Load Calculations

HEAT FLOW RATES

1. Space Heat Gain
a. Sensible Heat
b. Latent Heat Loads
2. Space Heat Gain vs Cooling Load Calculations
3. Space Cooling vs Cooling Load

COMPONENTS OF COOLING LOAD

COOLING LOAD CALCULATION METHOD

a. Transfer Function Method (TFM)
b. Cooling Load Temperature Differential/Cooling
Load Factors (CLTD/CLF)
c. Total Equivalent Temperature
Differential/Time-Averaging (TETD/TA)

DESIGN INFORMATION
1. Outdoor Design Weather Conditions
2. Indoor Design Conditions and Thermal
Comfort
3. Indoor Air Quality and Outdoor Air Quality
Requirements
4. Building Pressurization
5. Building Characteristics
6. Operating Schedules

COOLING LOAD METHODOLOGY

Considerations & Assumptions
1. Thermal Zoning
a. Two major zones:

CLTD/SCL/CLF METHOD OF LOAD

CALCULATION
Ashrae fundamentals 1997
a. CLTD
b. CLF