Oxbox J951X D Series, Installation Instructions Manual

11

•  Route piping as direct as possible between the furnace 

and the outdoors. Horizontal piping from inducer to 

the flue pipe must be sloped 1/4” per foot to ensure 

condensate flows towards the drain tee or PVC trap. 

Longer vent runs require larger pipe diameters. Refer to 

the Inducer & Venting Options section on 

page  15

 for 

additional information.

•  If a Direct Vent (2-pipe) system is used, the combustion 

air intake and the vent exhaust must be located in the 

same atmospheric pressure zone. This means both pipes 

must exit the building through the same portion of exterior 

wall or roof as shown in 

Figure 33 (page 36)

.

•  Piping must be mechanically supported so that its weight 

does not bear on the furnace. Pipe supports must be 

installed a minimum of every five feet along the vent run 

to ensure no displacement after installation. Supports 

may be at shorter intervals if necessary to ensure that 

there are no sagging sections that can trap condensate. 

It is recommended to install couplings along the vent 

pipe, on either side of the exterior wall (

Figure 33

). These 

couplings may be required by local code.

•  If breakable connections are required in the combustion 

air inlet pipe (if present) and exhaust vent piping, then 

straight neoprene couplings for 2” or 3” piping with hose 

clamps can be used. These couplings can be ordered 

through your local furnace distributor. To install a 

coupling:

1. Slide the rubber coupling over the end of the pipe that is 

attached to the furnace and secure it with one of the hose 

clamps.

2. Slide the other end of the rubber coupling onto the other 

pipe from the vent.

3. Secure the coupling with the second hose clamp, ensuring 

that the connection is tight and leak free.

Outdoor Terminations - Horizontal Venting

• Vent and combustion air intake terminations shall be 

installed as shown in 

Figure 7

 & 

Figure 8

 and in accordance 

with these instructions:

•  Vent termination clearances must be consistent with the 

NFGC, ANSI 2223.1/NFPA 54 and/or the CSA B149.1, 

Natural Gas and Propane Installation Code. 

Table 12 

(page  35)

 lists the necessary distances from the vent 

termination to windows and building air intakes.

• Vent and combustion air intake terminations must 

be located to ensure proper furnace operation and 

conformance to applicable codes. A vent terminal must 

be located at least 3 feet above any forced air inlet located 

within 10 feet. This does not apply to the combustion air 

inlet of a direct vent (two pipe) appliance. In Canada, 

CSA B149.1 takes precedence over these instructions. 

See 

Table 12

.

• All minimum clearances must be maintained to protect 

building materials from degradation by flue gases. See 

(

Figure 8

).

•  For optimal performance, vent the furnace through a wall 

that experiences the least exposure to winter winds.

• The vent termination shall be located at least 3 ft. 

horizontally from any electric meter, gas meter, regulator 

and any relief equipment. These distances apply ONLY 

to U.S. installations. In Canada, CSA B149.1 takes 

precedence over these instructions.

Figure 7. Inlet & Exhaust Pipe Clearances

12” min.

 to maximum 

expected sn

ow lev

el

(both pipes

)

90° Elbo

w

Exhaust v

ent

option 

B

Exhaust v

ent

option 

A

Mounting kit 

faceplate

secured to 

wall with scre

ws

(both pipes

)

Combustion

air inlet

Exhaust v

ent

option 

C

18” Min.

36” Max.

8” Min

.

36” Max.

(all positions)

Note 

2

Mechanical draft

vent terminal

Direct v

ent

terminal

50,000 Btuh

or less

Forced air inlet

Direct vent

terminal - more

than 50,000 Btuh

Mechanical 

draft 

vent 

ter

minal

Mechanical 

draft v

ent 

terminal

Less 

than

10 ft.

3 ft.

NOTES:
1. All dimensions shown are 
  minimum requirements.
2. Exterior vent terminations must 
  be located at least 12” above the
  maximum expected snow level.

Note 

2

4 ft

4 ft

12 in.

12 in.

9 in

.

Note 

2

Figure 8. Vent Locations

• Do not install the vent terminal such that exhaust is 

directed into window wells, stairwells, under decks or into 

alcoves or similar recessed areas, and do not terminate 

above any public walkways.

• If venting horizontally, a side wall vent kit is available 

according to the pipe diameter size of the installation. 2 

inch and 3 inch kits are available. Refer to the technical 

sales literature for part numbers. 

Please follow the 

instructions provided with the kit.

•  Concentric vent termination kits are available for use with 

these furnaces. Refer to the technical sales literature for 

kit numbers.

• When the vent pipe must exit an exterior wall close to 

the grade or expected snow level where it is not possible 

to obtain clearances shown in 

Figure 7

, a riser may be 

provided as shown in 

Figure 9 (page 12)

. Insulation is 

required to prevent freezing of this section of pipe. See 

Table 3 (page 15)

 for vent freezing protection.