Operating instructions

035-17452-000 Rev. B (0106)
4 Unitary Products Group
MULTIPLE APPLIANCE-INTERIOR OR EXTERIOR CHIMNEY
1. Seal any unused openings in the venting system. Inspect the venting system for proper size and horizontal pitch, as required in the National Fuel Gas
Code, ANSI Z233.1 or CAN/CGA B149 Canadian Installation Codes, and these instructions. Determine that there is not blockage or restriction, leak-
age, corrosion and other deficiencies which could cause an unsafe condition..
2. The vent tables are designed for two 90º elbows or equivalent. If additional elbows are used, five feet should be subtracted for each elbow from the
above values.
3. High altitude installation input rates shall be derated starting at 2000 ft. altitude. Sea level input rates shall be used for chimney sizing and venting
guidelines.
4. Vent connector length is limited to 1 1/2 ft. for each inch of vent connector diameter.
5. Vent connectors shall not be upsized more than two sizes greater than the listed appliance vent outlet diameter.
6. For multiple appliance installations, the flow area of the chimney shall not exceed 7 times the smallest draft hood outlet area.
FIGURE 2: Single Appliance Vent Connector
H
L
D
A
TYPE “B” DOUBLE WALL
GAS VENT USED
AS CONNECTOR
TILE LINED
MASONRY CHIMNEY
TABLE 3: Vent Table - Interior or Exterior Chimney
INTERIOR OR EXTERIOR CHIMNEYS
Capacity of Masonry Chimney Flue with Type B Double-Wall Vent Connectors Serving a Furnace Equipped
with the Tile Lined Chimney Kit, and One or More Draft Hooded Appliances
Type B Double-Wall Connector Diameter - D (inches)
To be used with chimney areas within the size limits at the bottom of table
Chimney
Height (ft)
Connector
Rise R (ft.)
Largest
3” 4” 5” 6” 7” 8”
Appliance Rating Limits in Thousands of BTU per Hour
NAT NAT NAT NAT NAT NAT
Max. Max. Max. Max. Max. Max.
6
1 204066101141200
2 285285124173232
3 346197143203270
10
1 224271108153216
2 295487129184247
3 35 63 100 148 208 281
15
1 254474114164229
2 315589134192260
3 35 64 102 153 215 292
20
1 254677119173239
2 315691138199270
3 35 65 104 157 222 301
30
1 254882127186255
2 325895145209287
3 36 66 107 163 233 317
50
1 255189143213294
2 33 61 102 160 235 326
3 36 69 115 180 260 357