JOHNSON CONTROLS
61
SECTION 3 - HANDLING, STORAGE, AND INSTALLATION
FORM 102.20-N1
ISSUE DATE: 7/06/2016
3
INSTALLING EXTERNAL VENT PIPING FOR
OUTDOOR AHUS
For outdoor AHUs with an overall height
less than 102 in (8 1/2 ft), the external
vent piping parts will be factory installed.
For outdoor AHUs with an overall height more than
102 in. (8 1/2 ft), the external vent piping parts will be
shipped loose for field mounting.
shows some generic instructions to install the
piping parts. An installation manual specific to the fuel
venting system will be provided.
Condensate Drain Arrangement
The indirect fired gas heat exchanger has the poten-
tial to create
highly acidic condensation
, particularly
during extended operation at low capacity or low fir-
ing rate conditions. To insure proper drainage, use the
following instructions as shown in
When constructing the condensate trap for the heat
exchanger drainage system, make sure the trap is tall
enough to handle the total static pressure (TSP) of the
indoor blower at low fire times. For example, if a TSP
is 6 in. at low fire, construct a trap that is 12 in. tall as
.
5.50
12
EXT.
7.75
FIGURE 96 -
GAS FURNACE FUEL VENTING SYSTEM
LD13326
FLUE CAP
VSI PIPE
SPLIT CLAMP
PIPE CHASE
SPLIT PLATE
RACEWAY
SIDE
PANEL
GAS FURNACE WITH CASING
HAT CHANNEL
ID
FAN
TRANSITION
PIECE
0.43 IN CLEARANCE
IVSI PIPE
SLIP JOINT
CURB
PIECE
CONTAINMENT
BAND SET, GASKET
AND INSULATION
FIBER
STORM COLLAR
STEP 1
STEP 2
STEP 3
STEP 4