Handbook of air conditioning and refrigeration / Shan K

CHAPTER 6
LOAD CALCULATIONS
6.1 SPACE LOAD CHARACTERISTICS 6.2
Space, Room, and Zone 6.2
Convective and Radiative Heat 6.2
Space and Equipment Loads 6.3
Night Shutdown Operating Mode 6.3
Influence of Stored Heat 6.6
6.2 COOLING LOAD AND COIL LOAD
CALCULATIONS 6.6
Components of Cooling Load 6.6
Components of Cooling Coil Load 6.7
Difference between Cooling Load and
Cooling Coil Load 6.8
Load Profile 6.9
Peak Load and Block Load 6.9
Characteristics of Night Shutdown
Operating Mode 6.10
Moisture Transfer from the Building
Structures 6.10
6.3 HISTORICAL DEVELOPMENT OF
COOLING LOAD CALCULATIONS 6.11
6.4 METHODOLOGY—HEAT
BALANCE 6.12
The Physical Model 6.12
Heat Balance Equations 6.12
Heat Balance of Space Air 6.13
Characteristics of Heat
Balance Method 6.14
6.5 METHODOLOGY—TRANSFER
FUNCTION 6.14
Basics 6.14
Transfer Function and Time Function 6.14
Calculation Procedure 6.15
CLTD/SCL/CLF Method 6.15
TETD/TA Method 6.15
6.6 DETAILED CALCULATION
PROCEDURES FOR TFM 6.16
Conduction Heat Gain through Exterior
Walls and Roofs 6.16
Heat Gain through Ceilings, Floors, and
Interior Partition Walls 6.16
Solar Heat Gain and Conductive Heat
Gain through Window Glass 6.17
Internal Heat Gain 6.17
Infiltration 6.24
Cooling Load Conversion Using Room
Transfer Function 6.24
Space Cooling Load Calculation 6.25
Heat Extraction Rate and Space Air
Transfer Function 6.25
Heat Loss to Surroundings 6.25
6.7 DETAILED CALCULATION PROCEDURE
USING CLTD/SCL/CLF METHOD 6.26
Space Cooling Load due to Heat Gain
through Exterior Walls and Roofs and
Conductive Gain through Glass 6.26
Space Cooling Load due to Solar Heat
Gain through Fenestration 6.28
Space Cooling Load due to Heat Gain
through Wall Exposed to
Unconditioned Space 6.28
Calculation of Internal Cooling Loads and
Infiltration 6.29
Space Cooling Load of Night Shutdown
Operating Mode 6.32
6.8 COOLING COIL LOAD 6.32
Basics 6.32
Fan Power 6.33
Duct Heat Gain 6.33
Temperature of Plenum Air and
Ventilation Load 6.34
6.9 COOLING LOAD CALCULATION BY
FINITE DIFFERENCE METHOD 6.34
Finite Difference Method 6.34
Simplifying Assumptions 6.36
Heat and Moisture Transfer at
Interior Nodes 6.36
Heat and Moisture Transfer at
Surface Nodes 6.37
Space Air Temperature and
Cooling Loads 6.38
6.10 HEATING LOAD 6.39
Basic Principles 6.39
Transmission Loss 6.39
Adjacent Unheated Spaces 6.40
Latent Heat Loss and Heat Loss from
Products 6.41
Infiltration 6.41
Setback of Night Shutdown
Operation 6.41
6.11 LOAD CALCULATION
SOFTWARE 6.42
Introduction 6.42
TRACE 600—Structure and Basics 6.42
TRACE 600 Input—Load
Methodology 6.43
TRACE 600 Input—Job 6.44
TRACE 600 Input—External Loads 6.45
TRACE 600 Input—Schedules 6.45
TRACE 600 Input—Internal Loads 6.46
TRACE 600 Input—Partition and Shading
Devices 6.47
TRACE 600—Minimum Input
Requirements, Run, and Outputs 6.47
REFERENCES 6.49
6.1