Outdoor Water Heaters

These heaters are design certified for outdoor installa- tion. Heaters must not be installed under an overhang of less than three (3) feet from the top on the heater. Three (3) sides must be open in the area under the overhang. Roof water drainage must be diverted away from the heaters installed under overhangs with the use of gutters.

The point from where the flue products exit the heater must be a minimum of four (4) feet below, four (4) feet horizontally from or one (1) foot above any door, win- dow or gravity inlet to a building. The top surface of the heater shall be at least three (3) feet above any forced air inlet, or intake ducts located within ten (10) feet hor- izontally.

Fig. 3: Outdoor Clearances from Openings

High Wind Conditions (Outdoor Units Only)

In areas where high winds are frequent, it may be nec- essary to locate the heater a minimum of 3' from high vertical walls, or install a wind break so the heater is not in direct wind current.

Combustion Air (Indoor Units Only) Air for Combustion and Ventilation

The heater must have both combustion and ventilation air. Minimum requirements for net free air supply openings are 12 inches from ceiling for ventilation and 12 inches from the floor for combustion air as outlined in ANSI Z223.1, and any local codes that may have jurisdiction.

CAUTION: Combustion air must not be contaminated by corrosive chemical fumes which can damage the heater. Measures must be taken to prevent the entry of corrosive chemical fumes to the combustion and ventilation air supply. Such chemicals include, but are not limited to, chlorinated and/or fluorinated hydrocarbons such as found in refrigerants, aerosol propellants, dry-cleaning fluids, degreasers, and paint removers. Other harmful elements may come from bleaches, air fresheners, or mastics. Vapors from these types of products can form corrosive acid compounds when burned in a gas flame. The resulting acidic condensate can damage or substantially reduce the life of the heater. It may become necessary to provide outside air directly to the heater in order to avoid this problem.

a. All Air From Inside The Building:

Each opening shall have a minimum net free square inches as noted:

	Square		Square
Model	Inches	Model	Inches
0133	136	1223	1223
0182/0181	181	1336	1337
0260/0261	264	1468	1467
0330/0331	334	1631	1630
0400/0401	399	1826	1826
0514	512	2100	2100
0624	627	2500	2499
0724	726	3001	3000
0824	825	3500	3500
0962	962	4001	4000
1125	1125

BOLD TYPE indicates Low NOx models.

Table E: All Air From Inside The Building

b. All Air From Outdoors:

When air is supplied directly from outside of building, each opening shall have a minimum net free square inches as noted:

	Square		Square
Model	Inches	Model	Inches
0133	34	1223	306
0182/0181	46	1336	335
0260/0261	66	1468	367
0330/0331	84	1631	408
0400/0401	100	1826	457
0514	128	2100	525
0624	157	2500	625
0724	182	3001	750
0824	207	3500	875
0962	241	4001	1000
1125	282

BOLD TYPE indicates Low NOx models.

Table F: All Air From Outdoors