16
ONLY USE GENUINE HAYWARD REPLACEMENT PARTS
51300803801 REV B
ALTITUDE OF INSTALLATION:
Hayward’s HDF heaters are rated for installations up to, and including, 2,000 ft above sea level.
WARNING:
Failure to comply with the appliance installation and service instructions in this manual may result in equipment damage,
fire, asphyxiation, or carbon monoxide poisoning. Exposure to products of incomplete combustion (carbon monoxide) can cause cancer
and birth defects or other reproductive harm.
AIR SUPPLY:
Indoor installations and outdoor shelters (confined spaces) must be provided with adequate combustion and ventilation air openings to assure
proper heater operation. These openings must be sized according to the requirements stated in paragraphs below (ALL AIR SUPPLY FROM
INSIDE THE BUILDING or ALL AIR SUPPLY FROM OUTDOORS whichever applies to the installation). These air openings must never be
obstructed when heater is in operation. These confined spaces shall be provided with 2 permanent openings, one commencing within 12 inch-
es of the bottom and one commencing within 12 inches of the top of the enclosure. The openings shall communicate directly, or by ducts, with
the outdoors or spaces (crawl or attic) that freely communicate with the outdoors. Ducts shall be of the same cross-sectional area as the free
area of the openings to which they connect. The minimum dimension of rectangular air ducts shall not be less than 3 inches. When air blowers
are used in spa/hot tub installations and are located in proximity to the heater, caution must be observed to ensure sufficient combustion air is
available to the heater for proper combustion. A separate blower air duct is recommended. Minimum installation clearances shown in Table 4
apply.
ALL AIR SUPPLY FROM INSIDE THE BUILDING:
The
confined space shall be provided with 2 permanent
openings communicating directly with an additional room
(s) of sufficient volume so that the combined volume of all
spaces meets the criteria for an unconfined space (a
space whose volume is not less than 50 cubic feet per
1,000 btu/hr of total input all gas utilization equipment
installed in the combined space shall). Each opening shall
have a minimum free area of 1 square inch per 1,000 btu/
hr of the total input, but not less than 100 square inches.
See Table 4 and Figure 7.
ALL AIR SUPPLY FROM OUTDOORS:
When
communicating with the outdoors through horizontal ducts,
each opening shall have a minimum free area of 1 square
inch per 2,000 btu/hr of total input See Table 4 and Figure
8B. When communicating with the outdoors (either directly
or through vertical ducts), each opening shall have a
minimum free area of 1 square inch per 4,000 btu/hr of
total input rating of all equipment in the enclosure. See
Table 4 and Figure 8A. When installing a heater below
ground (in a pit, for use with
Natural Gas only
),
combustion and ventilation air openings must be provided
as shown in Figure 9.
Table 4: Combustion and Ventilation Air Requirements
(sq. in.)*
Free Area per Total
Btu Requirement
Total Input
(Btu/hr)
Combustion
Air Free Area
Required
Ventilation Air
Free Area
Required
1 sq. in. per 1,000 Btu/hr
(Indoor Air)
400
400
1 sq. in. per 2,000 Btu/hr
(Outdoor Air thru Horz
duct)
200
200
1 sq. in. per 4,000 Btu/hr
(Outdoor Air direct or thru
Vert duct)
100
100
400,000
*For detailed methods of providing combustion and ventilation air, see latest edi-
tion of the National Fuel Gas Code (ANSI Z223.1/NFPA 54)
