STEP 8: INSTALLING AIR DISTRIBUTION COMPONENTS
All plenum duct and supply tubing runs as well as room
terminator locations must be in accordance with air
distribution system requirements listed in Section 1 of
this manual. Where taping of joints is required,
recommend Polyken # 222 tape or equivalent.
Plenum Duct Installation
All tees, elbows and branch runs must be a minimum of
18” from the fan coil unit or any other tee, elbow or
branch run. Keep all tees and elbows to a minimum to
keep system pressure drop on larger layouts to a
minimum. Plenum duct comes in 6-foot sections and may
be cut to length.
Begin installing plenum duct (see Figure 2.14). For
straight or branched plenum run cut off the female end
of a plenum duct section. In the case of a bull head
tee (see Unit No. 1 in Figure 1.3 on page 5) cut off
the male end of a plenum duct section.Then insert
duct into fan coil unit receiving collar. Push duct in tight
to form snug joint, flatten the sheet metal tabs against
the duct and insert flat head pins. Remove paper backing
on rectangular foam pieces and place over pins head.
Tape the unit/plenum joint securely. To prevent air
leakage and condensation, wrap and tape in place
the 6" wide piece of foil faced fiberglass insulation over
the taped joint. Be sure insulation is pushed up against
the unit.
Continue to assemble plenum duct, making sure shiplap
joints (see Figure 2.15) are snug and taped securely.
Remember, for the ESP-4860D system, a plenum tee
must be installed 18" minimum from the fan coil unit
before continuing plenum duct run (see air distribution
system requirements in Section 1 of this manual).
Plenum tee and elbow fittings may be installed at any
point in the plenum duct run. If installing a fitting at the
end of a full plenum section (see Figure 2.16), insert
female end of fitting into duct. If installing a fitting at a
“cut” in the plenum duct (see Figure 2.16), form a field-
fabricated flange (1
1
⁄
2
" wide) in the duct and insert male
end of fitting into duct. Tape the joint securely.
An end cap must be installed at the end of each duct run.
The cap contains an insulating cushion which is pushed
up tight against the duct end. (If installing end cap at the
end of a full plenum section, remove shiplap joint first).
Holding cap firmly in place (see Figure 2.17), insert flat
head pins through the sheet metal tabs on the end cap.
Remove paper backing on rectangular foam pieces and
place over pin heads. Cross-tape cap to the plenum duct,
and then tape it circumferentially to the plenum duct.
AAA
AAA
AAA
REMOVE FLANGE
PREPARING PLENUM
TAB
TAB
INSERTING
PLENUM
TAPED JOINT
INSULATED
JOINT
FIGURE 2.14: PLENUM INSTALLATION AT UNIT
FIGURE 2.15: PLENUM SHIP-LAP JOINT
13
AT END OF FULL
PLENUM SECTION
WHERE PLENUM
DUCT IS CUT
FORM
FLANGE
A
A
A
A
A
A
A
A
A
FIGURE 2.16: PLENUM FITTING INSTALLATION
