5
two permanent openings, one near the top of the
enclosure and another one near the bottom
(see
Figures 6 and 7).
Each opening shall communicate
directly or by means of ducts with the outdoors or
to such spaces (such as a crawl space) that freely
communicate with the outdoors and shall be sized
in accordance with the instructions in the section Air
Duct Sizing.
Air Duct Sizing
The air duct requirements should be met by one of the
following methods:
(a) vertical duct(s) with a free-flow area of not less
than one (1) square inch per 4,000 BTU/h (5.5
cm
2
/kWh) of the total input rating of all oil-fired
appliances in the enclosure;
(b) horizontal duct(s), as shown in
Figure 7,
with an
equivalent length of less than 50 ft (15 m), having a
free-flow area of not less than one (1) square inch
per 2,000 BTU/h (11 cm2/kWh) of the total input of
all oil-fired appliances in the enclosure; and
(c) air openings that communicate directly with the
outdoors, as shown in
Figure 6,
having a free-
flow area of not less than one (1) square inch per
4,000 BTU/h (5.5 cm2/kWh) of the total input rat-
ing of all oil-fired appliances in the enclosure.
Note:
Duct runs that are primarily horizontal and
that have an equivalent length greater than 50 ft
(15 m) should be sized larger as required to provide
the same airflow as would be provided by the
requirements of Item (b).
INSTALLATION INSTRUCTIONS
Figure 4
Figure 6
Figure 7
Figure 5
INSTALLATION INSTRUCTIONS
Man inst Oil -GI-IM001En-0211.indd 6
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