Instructions / Assembly

Heating and Cooling Essentials

Pipe size

(diameter

10"

12"

14"

Avg. cfm @

Static pressure

30 cfm

65 cfm

110 cfm

160 cfm

230 cfm

410 cfm

680 cfm

1000 cfm

Straight cut Right cut Left cut

28.5.4 Provide Adequate Airflow

A furnace located in a small utility room or closet

may not receive a sufficient amount of air for proper

combustion. If the furnace room is closed off, provide

an adequate air supply by installing two grilles in a

door or wall facing a well-ventilated area, Figure 28-17.

One grille should be in a high-wall position or at top

of the door, and the other should be in a low position.

28.6 Ductwork Tools

Persons working with air duct commonly use the

special hand tools shown in Figure 28-18. The name

of the tool describes its use. Other basic hand tools are

also needed. These might include a trouble light,

Return air

grilles

Plenum

Note: Aviation snips are used for cutting

holes in sheet metal. Never use them to cut wire.

1"X 30" tape

Ball pein hammer

Figure 28-17. Two grilles in a closet door provide sufficient

airflow for furnace operation and return air.

Hand crimper

Figure 28-18. Hand tools often are named according to the

job they perform.