Operating instructions
Example: The boiler is rated at 100,000 Btuh. The water heater is rated at 30,000 Btuh. The total is 130,000 Btuh. Two grilles are needed, each
with 130 sq in. of FREE opening. Metal grilles have about 60 percent FREE area. To find the louvered area needed, multiply the FREE area
required by 1.7 (130 X 1.7 = 221.0 sq in. louvered area). In this example, 2 grilles each having an 8 in. X 30 in. (240 sq in.) louvered area would
be used. Fig. 5 shows grille locations.
ALL AIR FROM OUTDOORS
The confined space shall be provided with 2 permanent openings, 1 commencing within 12-in. of the top and 1 commencing within 12-in. of the
bottom 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.
1. When directly communicating with the outdoors, each opening shall have a minimum free area of 1 sq in. per 4000 Btuh of total input rating
of all equipment in the enclosure.
2. When communicating with the outdoors through vertical ducts, each opening shall have a minimum free area of 1 sq in. per 4000 Btuh of
total input rating of all equipment in the enclosure.
3. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 sq in. per 2000 Btuh
of total input rating of all equipment in the enclosure.
4. When ducts are used, they 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-in.
PROCEDURE 3—BOILERS WITH TANKLESS HEATER COIL
Boilers may be factory packaged with a tankless heater coil.
The use of this coil eliminates the need for a hot water storage tank. Instantaneous heating of water in the coil provides a flow of hot water for
domestic use if proper burner and water supply line controls are used. Tankless coils are meant to provide domestic hot water for intermittent
draws, not continuous flows.
Fig. 3—Minimum Clearance Dimensions
A95592
24″ MIN
6″
6″ MIN
6″ MIN
18″ WITH COIL
BOILER
FRONT
Fig. 4—General Principal Requirements for a Typical Installation
A02230
TO OUTSIDE
OIL
FILTER
SHUTOFF
VALVE
OIL
TANK
VENT PIPE
OIL BURNER
OIL LINES
VENT PIPE
MINIMUM 2 IN. ID
2 IN. FILL PIPE
AUTOMATIC
FILL VALVE
AND SHUTOFF
DIAPHRAGM
EXPANSION TANK
DRAFT
REGULATOR
FOUNDATIONS
ELECTRIC LINE
SERVICE LINE
ENTRANCE
SWITCH
OVERCURRENT
PROTECTED
SAFETY SWITCH
LINES TO OTHER
APPLIANCES
C
H
I
M
N
E
Y
FROM RADIATION
RELIEF VALVE
TO RADIATION
CIRCULATING PUMP
IN SUPPLY LINES
—7—
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