Louisville Tin and Stove 90N30A - Manual (Page 8)

If more than one gas appliance is vented through
a common vent system, the vent should be
increased in size to accommodate the increased
load. Consult your local code or the tables in the
latest edition of NFPA54/ANSI.Z223.1 for the
correct size. If no local codes apply, use the
following alternate method for sizing a vent
connected to more than one appliance. The
effective area of the vent must be not less than
the area of the largest vent connection plus 50
percent of the areas of additional draft hood
outlets.
The homeowner appreciates neatness in
workmanship and the neat installation usually
functions better than the sloppy one. Double
check your work to verify that all clearances around
the floor furnace and vent system are adequate
and that the vent system is installed to code or
pipe manufacturers specifications. See Figure 10.
CONNECTING THE VENT - Continued
Typical Installation Using
Class “B” Vent Pipe
1. Adequate clearances around floor furnace.
2. Draft Diverter 6” from combustibles.
3. Adequate clearances around vent pipe.
4. Horizontal vent pipe sloping upward 1/4” per foot.
5. Pipe supported with metal straps.
6. Adequate height of vent system.
7. Listed vent cap.
FIGURE 10
GAS SUPPLY AND PIPING
The gas piping system must meet the requirements of local codes or the specifications of the servicing gas supplier. It must
have adequate capacity to supply the floor furnace and any other appliance within the home with enough gas to maintain the
full rated capacities without excessive pressure drop when all appliances are operating at full rate.
Where local conditions include earthquake, tornado, unstable ground or flood hazards, give special consideration to
increased strength and flexibility of piping supports and connections. Consult local authorities for recommendations.
All unused openings in the piping system must be securely closed gas-tight.
Support the piping or tubing at regular intervals with
metal pipe strapping. See chart below.
Page 8
Length of **Copper Tubing **Steel Pipe
Length of INSIDE PIPE DIAMETER Pipe/Tubing Outside Diameter Inside Diameter
Pipe - Feet 1/2” 3/4” 1 ” Feet 1/2” 3/4” 1/2” 3/4”
1 0 132,000 278,000 520,000 1 0 92,000 329,000 275,000 567,000
2 0 92,000 190,000 350,000 Capacity 2 0 62,000 216,000 189,000 393,000 Capacity
3 0 73,000 152,000 285,000 B.T.U. 3 0 50,000 181,000 152,000 315,000 B.T.U.
4 0 63,000 130,000 245,000 Per Hour 4 0 41,000 145,000 129,000 267,000 Per Hour
5 0 56,000 115,000 215,000 Input 5 0 37,000 131,000 114,000 237,000 Input
6 0 50,000 105,000 195,000 6 0 35,000 121,000 103,000 217,000
*Based on heating value of 1,000 btu per cubic foot (specific gravity *Undiluted Liquefied Petroleum Gas @ 11 inches water column inlet
of 0.6) @ 0.5 PSIG and a pressure drop of 0.3 inch water column. pressure. Based on a pressure drop of 0.5 inches water column.
**Copper tubing must comply with limitations of NATIONAL FUEL
GAS CODE reference 2.6.3 metallic tubing.
***Steel pipe should be of at least standard weight (Schedule 40).
GAS PIPE SIZES - CAPACITY - *NATURAL GAS
GAS TUBING AND PIPE SIZES - CAPACITY -
*L.P. GAS
Nominal Steel Spacing of Nominal size of Spacing of
Pipe Size Supports tubing O.D. Supports
1/2” 6 ’ 1/2” 4 ’
3/4” or 1” 8 ’ 5/8” or 3/4” 6 ’