Lochinvar 402 - 2072 operation manual Outside Combustion Air Using Direct Venting

Installation & Operation Manual

1 Determine unit location (continued)

All dimensions are based on net free area in square inches. Metal louvers or screens reduce the free area of a combustion air opening a minimum of approximately 25%. Check with louver manufacturers for exact net free area of louvers. Where two openings are provided, one must be within 12" (30 cm) of the ceiling and one must be within 12" (30 cm) of the floor of the equipment room. Each opening must have a minimum net free area as specified in TABLE 1C, page 11. Single openings shall be installed within 12" (30 cm) of the ceiling.

Figure 1-5_Outside Combustion Air Through Ducts

4. Outside Combustion Air - Using Direct Venting

With this option, you can connect combustion air vent piping directly to the unit. See the information under Direct Venting starting on page 26 for specific information regarding this option.

￿CAUTION

The combustion air supply must be completely free of any flammable vapors that may ignite or chemical fumes which may be corrosive to the appliance. Common corrosive chemical fumes which must be avoided are fluorocarbons and other halogenated compounds, most commonly present as refrigerants or solvents, such as Freon, trichlorethylene, perchlorethylene, chlorine, etc. These chemicals, when burned, form acids which quickly attack the heat exchanger finned tubes, headers, flue collectors, and the vent system. The result is improper combustion and a non- warrantable, premature unit failure.

TABLE - 1C

MINIMUM RECOMMENDED COMBUSTION

AIR SUPPLY TO EQUIPMENT ROOM

	*Outside Air from			Inside Air from		Inside Air from
Model	2 Openings Directly from		*Outside Air from	2 Ducts Delivered from		2 Ducts Delivered from Interior
	Outdoors		1 Opening Directly	Outdoors		Space
Number
	Top	Bottom	from Outdoors, in2	Top	Bottom	Top	Bottom
	Opening, in2	Opening, in2		Opening, in2	Opening, in2	Opening, in2	Opening, in2
402	100	100	133	200	200	400	400
	(645 cm2)	(645 cm2)	(858 cm2)	(1291 cm2)	(1291 cm2)	(2581 cm2)	(2581 cm2)
502	125	125	167	250	250	500	500
	(806 cm2)	(806 cm2)	(1077 cm2)	(1613 cm2)	(1613 cm2)	(3226 cm2)	(3226 cm2)
652	163	163	217	325	325	650	650
	(1052 cm2)	(1052 cm2)	(1400 cm2)	(2097 cm2)	(2097 cm2)	(4194 cm2)	(4194 cm2)
752	188	188	250	375	375	750	750
	(1213 cm2)	(1213 cm2)	(1613 cm2)	(2420 cm2)	(2420 cm2)	(4839 cm2)	(4839 cm2)
992	248	248	330	495	495	990	990
	(1600 cm2)	(1600 cm2)	(2129 cm2)	(3194 cm2)	(3194 cm2)	(6388 cm2)	(6388 cm2)
1262	315	315	420	630	630	1260	1260
	(2032cm2)	(2032cm2)	(2710 cm2)	(4065 cm2)	(4065 cm2)	(8130 cm2)	(8130 cm2)
1442	360	360	480	720	720	1440	1440
	(2323cm2)	(2323cm2)	(3097 cm2)	(4646 cm2)	(4646 cm2)	(9291 cm2)	(9291 cm2)
1802	450	450	600	900	900	1800	1800
	(2903cm2)	(2903cm2)	(3871 cm2)	(5807 cm2)	(5807 cm2)	(11614 cm2)	(11614 cm2)
2072	518	518	690	1035	1035	2070	2070
	(3342cm2)	(3342cm2)	(4452 cm2)	(6678 cm2)	(6678 cm2)	(13356 cm2)	(13356 cm2)

*Outside air openings shall directly communicate with the outdoors. When combustion air is drawn from the outside through a duct, the net free area of each of the two openings must have twice (2 times) the free area required for Outside Air/2 Openings. The above requirements are for the boiler only; additional gas fired appliances in the equipment room will require an increase in the net free area to supply adequate combustion air for all appliances.

11