ECR International G95V, Руководство по установке и эксплуатации

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FIGURE 4 - COMBUSTION/DILUTION AIR FROM
HEATED INSIDE SOURCES (CASE 2)
10 - DETERMINING COMBUSTION AIR
CASE 1 - FURNACE LOCATED IN AN UNCON-
FINED SPACE
Unconfined space does not necessarily mean that
ventilation will not have to be introduced from the
outdoors, particularly in airtight homes. The minimum
requirement for unconfined space is a volume of 50
cubic feet for each 1000 BTU/Hr for all fuel burning
appliances located within the unconfined area.
If the amount of combustion and ventilation air is in-
sufficient to properly operate the furnace and other
fuel burning appliances within the unconfined area,
it will be necessary to supply it from the outdoors
based on the criteria used when calculating the air
supply for a confined space.
NOTE: If planning to use the inside air in an unconfined
space, remember to test for proper furnace operation (as well
as other fuel burning appliances located within the unconfined
space) with respect to adequate combustion and ventilation
air with fireplace dampers open, clothes dryer running, bath-
room exhaust fans on, kitchen range hood on, etc.
CASE 2 - FURNACE LOCATED IN A CONFINED
SPACE
A confined space, (any space smaller than the
minimums discussed in Case 1), must have two air
openings; one within 12” of the ceiling and the oth-
er within 12” of the floor. The air openings must be
sized based on whether the combustion and ven-
tilation air is being taken from indoors or outdoors,
the method outdoor air (if used) is introduced, and
taking into account any other fuel burning applianc-
es in the confined space.
If sufficient indoor combustion and ventilation air is
available for the furnace and all other fuel burning
appliances, size each opening on the basis of one
square inch of free area per 1000 BTU/Hr. (Figure 4)
NOTE: Be sure to consider all clothes dryers, bathroom
fans, range hoods, etc., when making this calculation.
The minimum requirement for these openings is
100 square inches, even for the furnace models
under 100,000 BTU/Hr.
NOTE: If using grilles to cover the two openings, factor in
the free area of the grille. Typically, a sidewall grille will
have a free area approximately 50% of its nominal size.
Consequently, if the required opening is 10 x 10, it will have
to be doubled if using a sidewall grille with 50% free area.
IMPORTANT: If an exhaust fan, fireplace, clothes
dryer or any similar device is present in the indoor
area from which the combustion and ventilation air
will be drawn, negative pressure could be a prob-
lem if natural infiltration from the outdoors does not
match the rate at which air is exhausted.
CASE 3 - FURNACE LOCATED IN A CONFINED
SPACE, OUTDOOR AIR FROM ATTIC OR CRAWL
SPACE
In this circumstance, the free area of each of the two
combustion and ventilation air openings is based
on a minimum of 1 square inch per 4000 BTU/Hr. In
this configuration, one opening can originate from
the floor drawing combustion and ventilation air
from the ventilated crawl space.