Lennox International Inc G50UH-60D-155 Vent, Serving Two or More Category I Appliances

				TABLE 7
			Vent	Connector	Capacity
		Type B Double-Wall Vents with Single-Wall Metal Connectors
		Serving Two or More Category I Appliances
Vent	Connector			Vent and Connector Diameter - D (inches)
Height	Rise	3 Inch		4 Inch			5 Inch		6 Inch
H	R		Appliance Input		Rating	in Thousands	of Btu Per Hour
(feet)	(feet)	MIN	MAX	MIN	MAX	MIN	MAX	MIN	MAX
	I	NR	NR	NR	NR	NR	NR	NR	NR
6	2	NR	NR	NR	NR	NR	NR	168	182
	3	NR	NR	NR	NR	121	131	174	198
	1	NR	NR	79	87	116	138	177	214
15	2	NR	NR	83	94	121	150	185	230
	3	NR	NR	87	100	127	160	193	243
	1	47	60	77	110	113	175	169	278
30	2	50	62	81	115	117	185	177	290
	3	54	64	85	119	122	193	185	300
				TABLE 8
			Common Vent Capacity
		Type B Double-Wall Vents with Single-Wall Metal Connectors
		Serving Two or More Category I Appliances
Vent			Common Vent Diameter - D (inches)
Height	4 Inch		5 Inch			6 Inch		7 Inch
H			Appliance	Input Rating	in Thousands of Btu		Per Hour
(feet)	FAN + FAN	FAN + NAT	FAN + FAN	FAN + NAT		FAN + FAN	FAN + NAT	FAN + FAN	FAN + NAT
6	89	78	136	113		200	158	304	244
8	98	87	151	126		218	173	331	269
10	106	94	163	137		237	189	357	292
15	121	108	189	159		275	221	416	343
20	131	118	208	177		305	247	463	383
30	145	132	236	202		350	286	533	446

Removal of the Furnace from Common Vent

In the event that an existing furnace is removed from a venting system commonly run with separate gas ap- pliances, the venting system is likely to be too large to properly vent the remaining attached appliances,

Conduct the following test while each appliance is operat- ing and the other appliances (which are not operating) re- main connected to the common venting system. If the venting system has been installed improperly, you must correct the system as indicated in the general venting re- quirements section,

1 - Seal any unused openings in the common venting sys- tem.

_ Inspect the venting system for proper size and horizontal pitch, Determine that there is no blockage, restriction,

leakage, corrosion, or other deficiencies which could cause an unsafe condition,

3 - Close all building doors and windows and all doors be- tween the space in which the appliances remaining connected to the common venting system are located

and other spaces of the building. Turn on clothes dry- ers and any appliances not connected to the common venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will oper- ate at maximum speed. Do not operate a summer ex- haust fan. Close fireplace dampers,

4 - Follow the lighting instructions, Turn on the appliance that is being inspected. Adjust the thermostat so that the appliance operates continuously,

5 - After the main burner has operated for 5 minutes, test for leaks of flue gases at the draft hood relief opening, Use the flame of a match or candle, or smoke from a cigarette, cigar, or pipe,

6 - After determining that each appliance connected to the common venting system is venting properly, (step 3) return all doors, widows, exhaust fans, fireplace damp- ers, and any other gas-burning appliances to their pre- vious mode of operation,

7 - If a venting problem is found during any of the preced- ing tests, the common venting system must be modi- fied to correct the problem,

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