Lochinvar 399 - Manual (Page 24)

Hydronic Heating Boilers and
Domestic Water Heaters
24
INSTALLATION Continued
Horizontal DV Venting Termination
Horizontal venting uses the unit’s internal combustion air
blowers to force the flue products out of the horizontally-
terminated flue.
You must purchase a horizontal direct vent kit from the
appliance manufacturer to ensure proper operation. See
TABLE–G, page 24 to determine which horizontal direct vent
kit you need. When installing the vent cap, the wall opening
must provide an air space clearance of 2 inches (5.1cm) around
the flue pipe. The diameter of the opening for installation of
the sidewall cap will be 4 inches (10.2cm) larger (minimum)
than the nominal diameter of the installed vent pipe to the
horizontal vent cap.
Install the horizontal vent cap from the outside. Mount the vent
cap to the wall using four screws or wall anchors. Seal under
the screw heads with caulking. Install the Category IV vent
pipe from the unit to the vent cap. See detailed instructions
packed with the horizontal direct vent kit.
Horizontal Vent Termination Clearances and
Location
Follow all sidewall venting termination information for
clearances and location under Sidewall Vent Termination
Clearances and Location, page 12.
* The DVK kits include a DV box adapter, air inlet cap, and a sidewall vent
termination. The VDK kits include a DV box adapter and an air inlet cap.
Flue Pipe Materials
The following manufacturers supply flue materials suitable for
these models. All materials are made with AL29-4C stainless
steel. Call the following numbers for the nearest distributor.
Heat-Fab, Inc. Saf-T CI Vent. 1-800-772-0739.
Protech Systems, Inc. Fas-N-Seal Vent. 1-800-766-3473.
Metal-Fab, Inc. Corr/Guard Vent. 1-800-835-2830.
Combustion Air Inlet Piping
The Direct Vent system requires the installation of a pipe to
supply combustion air from the outdoors directly to the unit.
Make sure the combustion air inlet is in the same pressure zone
as the vent terminal.
In cold climates, use a Type-B double-wall vent pipe or an
insulated single wall pipe for combustion air. This will help
prevent moisture in the cool incoming air from condensing and
leaking from the inlet pipe.
Length of Air Inlet Pipe
The installed length of air inlet pipe from the unit to the outside
air inlet cap must not exceed 50 equivalent feet (15.2m).
Subtract 5 feet (1.5m) of equivalent length for each 90° elbow.
Subtract 2.5 feet (0.7m) of equivalent length for each 45°
elbow.
Do not exceed the limits for the combustion air inlet piping
lengths.
Connecting the Air Inlet Pipe to the Unit
Connect the air inlet piping directly to the unit by attaching it
to the DV box adapter. The DV box adapter is included in the
direct vent kits for horizontal direct vent. The combustion air
inlet area of the unit is located at the right rear corner of the
unit. This unit uses a simple air filter to ensure clean air is used
for the combustion process. Attach the DV box adapter over
the air filter (see FIG. 24). Align screw holes on the DV box
adapter with the screw holes surrounding the air filter hanger.
Insert sheet metal screws and tighten firmly.
FIG. 24 Attaching DV Box Adapter to Unit
Input Horizontal Vertical
Btu/hr Kit* Kit*
399,999 DVK3004 VDK3026
500,000 DVK3004 VDK3026
650,000 DVK3005 VDK3027
750,000 DVK3005 VDK3027
990,000 DVK3000 VDK3023
1,260,000 DVK3001 VDK3024
1,440,000 DVK3001 VDK3024
1,800,000 DVK3002 VDK3024
2,070,000 DVK3002 VDK3024
TABLE-G
Direct Vent Kits
ƽ
CAUTION: Units that are shut down or will
not operate may experience freezing due to
convective airflow in the air inlet pipe.