Section 6
Ductwork & Accessories


6.1 Circle Areas and Circumferences

6.2

Coil Pressure Drops

6.2.1

Cooling

6.2.2

Heating

6.3

Equivalents

6.3.1

Rectangular Duct Surface Area  

in Square Feet Per Linear Foot

6.3.2

Rectangular Equivalents with 

Aspect Ratios for Round Duct

6.3.3

Round Equivalents of 

Rectangular Ducts, Graphical

6.3.4

Round Equivalents of 

Rectangular Ducts, including 

Duct Class

6.3.5

Round and Rectangular 

Equivalents for  Spiral Flat Oval 

Ducts

6.4

Filter Pressure Loss Data

6.5

Friction of Air in Ducts

6.5.1

Correction Factors

6.5.1.1

Double-Wall Ducts

6.5.1.2

Various Ducts, ASHRAE 1993

6.5.1.3

Various Ducts, ASHRAE 1981

6.5.2

Fiberglas

6.5.2.1

Duct Board

6.5.2.2

Duct Liner

6.5.3

Flexible Ducts

6.5.4

Steel, Straight, Round Ducts

6.5.4.1

ASHRAE 1993

6.5.4.2

ASHRAE 19491

6.5.4.3

Carrier

6.6

Gauge Recommendations

6.6.1

Flat Oval

6.6.2

Rectangular

6.6.2.1

Low and High Pressures

6.6.2.2

High Negative Pressures

6.6.3

Round

6.6.3.1

Low and High Pressures

6.6.3.2

High Negative Pressures

6.7

Louvers

6.7.1

2" Free Areas

6.7.2

4" Free Areas

6.7.3

6" Free Areas

6.8 Pressure-Velocity

Classifications

6.9 PVC Duct and Hood 

Systems Specifications

6.10

Registers, Grilles and 

Diffusers

6.10.1

Diffusers

6.10.1.1

Round

6.10.1.2

Slot

6.10.1.3

Square

6.10.2

Registers and Grilles

6.10.2.1

Supply

6.10.2.2

Return

6.11

Seal Class

6.12

Sound Data

6.12.1

Discussion

6.12.2

Indoor Design Goals

6.13

Velocities

6.13.1

Duct

6.13.1.1

ASHRAE

6.13.1.2

Carrier

6.13.2

Grilles

6.13.2.1

 Supply

6.13.2.2

Return

6.14

Weights

6.14.1

Sheet

6.14.1.1

Copper

6.14.1.2

Steel and Aluminum

6.14.2

Steel Duct

6.14.2.1

Flat Oval, Spiral

6.14.2.2

Rectangular

6.14.2.3

Round, Spiral