16
Page
Determine type of ventilation
dŚĞƌĞĂƌĞƐĞǀĞƌĂůƚLJƉĞƐŽĨǀĞŶƟůĂƟŽŶƚŚĂƚĐĂŶďĞƵƐĞĚ͘dŚĞǀĂƌŝŽƵƐŽƉƟŽŶƐĂƌĞůŝƐƚĞĚďĞůŽǁ͘^ĞĞĂůƐŽƚŚĞ
ŝůůƵƐƚƌĂƟŽŶƐŽŶƚŚĞŶĞdžƚƉĂŐĞ͘
1. Direct to outdoors
2.
sĞƌƟĐĂůĚƵĐƚƐ
3. Horizontal
ducts
4. Single opening (not recommended; must be at least 100 in
2
(6.5 cm
2
Ϳ͘EŽƚĂƉƉƌŽƉƌŝĂƚĞĨŽƌĐŽŶĮŶĞĚ
ƐƉĂĐĞƐƐŵĂůůĞƌƚŚĂŶϱϬŌ
3
(1.42 m
3
ͿƉĞƌϭ͕ϬϬϬdhͬŚŽƌǁŚĞŶŐĞƫŶŐĂŝƌĨƌŽŵĂŶŽƚŚĞƌƌŽŽŵ͘Ϳ
5. From a larger room inside the house (not recommended – refer to "Calculate the air volume of the room"
above to determine if the combined volume of the rooms may be adequate).
Determine minimum free area required for each vent opening
dŚĞƐŝnjĞŽĨƚŚĞǀĞŶƚŽƉĞŶŝŶŐƐĚĞƉĞŶĚƐŽŶƚŚĞƚŽƚĂůdhͬŚƌĂƟŶŐŽĨĂůůĂƉƉůŝĂŶĐĞƐŝŶƚŚĞƐƉĂĐĞ;ƵƐĞLJŽƵƌĐĂůĐƵůĂƟŽŶ
from “Before beginning”) and the type of vent used.
Table 1
provides the minimum free area for each vent opening
ĚĞƉĞŶĚŝŶŐŽŶƚŚĞƚLJƉĞŽĨǀĞŶƟůĂƟŽŶ͘
Calculate minimum size of vent openings and ducts
dŚĞǀĞŶƚĐƌŽƐƐͲƐĞĐƟŽŶĂůĂƌĞĂŶĞĞĚĞĚƚŽƉƌŽǀŝĚĞƚŚĞĨƌĞĞĂƌĞĂĚĞƉĞŶĚƐŽŶƚŚĞĐŽǀĞƌŝŶŐŽŶƚŚĞǀĞŶƚŽƉĞŶŝŶŐƐ͘dLJƉŝĐĂů
vents use louvers or grilles to protect the opening. The louver or grill itself blocks some of the free area, so the open-
ing may need to be larger to meet the minimum free area requirements.
hƐĞƚŚĞĨŽůůŽǁŝŶŐĨŽƌŵƵůĂƚŽĐĂůĐƵůĂƚĞƚŚĞƌĞƋƵŝƌĞĚĐƌŽƐƐͲƐĞĐƟŽŶĂůĂƌĞĂ͗
ƌŽƐƐͲƐĞĐƟŽŶĂůĂƌĞĂсŵŝŶŝŵƵŵĨƌĞĞĂƌĞĂƌĞƋƵŝƌĞĚрƉĞƌĐĞŶƚĨƌĞĞĂƌĞĂŽĨĐŽǀĞƌŝŶŐ;ŝŶĚĞĐŝŵĂůƐʹĞ͘Ő͕͘ϲϬйсϬ͘ϲͿ
&ŽƌĞdžĂŵƉůĞ͕ĂŶŝŶƐƚĂůůĂƟŽŶĂƌĞĂƚŚĂƚƌĞƋƵŝƌĞƐŽƉĞŶŝŶŐƐǁŝƚŚϭϬϬŝŶ
2
(645 cm
2
) of free area would need
134 in
2
(865 cm
2
ͿŽƉĞŶŝŶŐƐŝĨƵƐŝŶŐŵĞƚĂůůŽƵǀĞƌƐƌĂƚĞĚĂƚϳϱйĨƌĞĞĂƌĞĂ;ϭϬϬŝŶ
2
рϬ͘ϳϱсϭϯϰŝŶ
2
).
/ĨLJŽƵĚŽŶŽƚŬŶŽǁƚŚĞйĨƌĞĞĂƌĞĂĨŽƌLJŽƵƌůŽƵǀĞƌŽƌŐƌŝůů͕ƵƐĞƚŚĞĨŽůůŽǁŝŶŐǀĂůƵĞƐ͗
ͻ
&ŽƌǁŽŽĚůŽƵǀĞƌƐŽƌŐƌŝůůĞƐ͗Ϯϱй
ͻ
&ŽƌŵĞƚĂůůŽƵǀĞƌƐŽƌŐƌŝůůĞƐ͗ϳϱй
&ŽůůŽǁƚŚĞƐĞƌƵůĞƐƚŽĞŶƐƵƌĞƚŚĂƚǀĞŶƚƐĂŶĚĚƵĐƚƐƉƌŽǀŝĚĞĂĚĞƋƵĂƚĞĂŝƌŇŽǁ͗
ͻ
Each vent opening must be no smaller than 100 in
2
(645 cm
2
).
ͻ
ƵĐƚƐŵƵƐƚŚĂǀĞƚŚĞƐĂŵĞĐƌŽƐƐͲƐĞĐƟŽŶĂůĂƌĞĂĂƐĨƌĞĞĂƌĞĂŽĨƚŚĞŽƉĞŶŝŶŐ͘
ͻ
Rectangular ducts must have a minimum dimension of no less than 3 in (76 mm).
ͻ
All screens must have mesh ¼” or larger.
ͻ
DŽǀĞĂďůĞůŽƵǀĞƌƐŵƵƐƚďĞůŽĐŬĞĚŽƉĞŶŽƌŝŶƚĞƌĐŽŶŶĞĐƚĞĚǁŝƚŚƚŚĞĞƋƵŝƉŵĞŶƚƐŽƚŚĂƚƚŚĞLJŽƉĞŶĂƵƚŽŵĂƟ
-
ĐĂůůLJĚƵƌŝŶŐŽƉĞƌĂƟŽŶ͘
ͻ
<ĞĞƉůŽƵǀĞƌƐĂŶĚŐƌŝůůƐĐůĞĂŶĂŶĚĨƌĞĞŽĨĚĞďƌŝƐŽƌŽƚŚĞƌŽďƐƚƌƵĐƟŽŶƐ͘
Check that air source is clean and free of chemicals
ŝƌĨŽƌĐŽŵďƵƐƟŽŶĂŶĚǀĞŶƟůĂƟŽŶŵƵƐƚďĞĐůĞĂŶĂŶĚĨƌĞĞŽĨĐŽƌƌŽƐŝǀĞŽƌŇĂŵŵĂďůĞĐŚĞŵŝĐĂůƐ͘ĨĂŝůƵƌĞĚƵĞƚŽĐŽƌ
-
ƌŽƐŝǀĞĐŚĞŵŝĐĂůƐŝŶƚŚĞĂŝƌŝƐŶŽƚĐŽǀĞƌĞĚďLJƚŚĞǁĂƌƌĂŶƚLJ͘ŽŵďƵƐƟŽŶĂŝƌŵƵƐƚďĞĨƌĞĞŽĨĂĐŝĚͲĨŽƌŵŝŶŐĐŚĞŵŝĐĂůƐƐƵĐŚ
ĂƐƐƵůĨƵƌ͕ŇƵŽƌŝŶĞ͕ĂŶĚĐŚůŽƌŝŶĞ͘ĞƐƵƌĞƚŚĂƚĂŝƌĂƚƚŚĞǀĞŶƚŝŶůĞƚƐŝƐĨƌĞĞŽĨƐƵĐŚĐŚĞŵŝĐĂůƐ͘
See graphics on next page.
Table 1
DŝŶŝŵƵŵ&ƌĞĞƌĞĂŽĨWĞƌŵĂŶĞŶƚKƉĞŶŝŶŐƐĨŽƌsĞŶƟůĂƟŽŶĂŶĚŽŵďƵƐƟŽŶŝƌ^ƵƉƉůLJʹŝƌĨƌŽŵŽƵƚĚŽŽƌŽƌ
indoor spaces.
ĂƐĞĚŽŶƚŚĞƚŽƚĂůdhͬŚŝŶƉƵƚƌĂƟŶŐĨŽƌĂůůŐĂƐďƵƌŶŝŶŐĂƉƉůŝĂŶĐĞƐǁŝƚŚŝŶĂĐŽŶĮŶĞĚƐƉĂĐĞ͘
Opening Source
Minimum Free Area
Direct to outdoors*
1
in
2
(6.5
cm
2
) per 4,000 BTU/hr (see Figure
1, 2
)
sĞƌƟĐĂůĚƵĐƚƐ
1
in
2
(6.5
cm
2
) per 4,000 BTU/hr (see Figure
3
)
Horizontal ducts
1
in
2
(6.5
cm
2
) per 2,000 BTU/hr (see Figure
4
)
Single Opening
1
in
2
(6.5
cm
2
) per 3,000 BTU/hr (see Figure
5
)
Two permanent openings
to another room**
1
in
2
(6.5
cm
2
) per 1,000 Btu/hr (see Figure
6
)
Opening: 100 in
2
(645 cm
2
) MIn
Minimum dimension of air openings:
no less than 3 in (76 mm)
ΎdŚĞƐĞŽƉĞŶŝŶŐƐĐŽŶŶĞĐƚĚŝƌĞĐƚůLJǁŝƚŚƚŚĞŽƵƚĚŽŽƌƐƚŚƌŽƵŐŚĂǀĞŶƟůĂƚĞĚĂƫĐ͕ĂǀĞŶƟůĂƚĞĚĐƌĂǁůƐƉĂĐĞ͕ŽƌƚŚƌŽƵŐŚ
an outside wall.
ΎΎhŶŝƚĞĚ^ƚĂƚĞƐ͗&ŽƌĚŝƌĞĐƟŽŶŽŶĐŽŵďŝŶŝŶŐƐƉĂĐĞƐŝŶĚŝīĞƌĞŶƚƐƚŽƌŝĞƐǁŝƚŚŝŶƚŚĞƐƚƌƵĐƚƵƌĞ͕ƌĞĨĞƌƚŽƚŚĞĐƵƌƌĞŶƚĞĚŝ
-
ƟŽŶŽĨƚŚĞEĂƟŽŶĂů&ƵĞů'ĂƐŽĚĞE^/ϮϮϯ͘ϭͬE&Wϱϰ͘/ŶĂŶĂĚĂ͕ĐŽŶƚĂĐƚLJŽƵƌůŽĐĂůĐŽĚĞĞŶĨŽƌĐĞŵĞŶƚĂŐĞŶĐLJĨŽƌ
ĚŝƌĞĐƟŽŶ͘
/ŶƐƚĂůůĂƟŽŶ
/ŶƐƚĂůůĂƟŽŶDĂŶƵĂů
Printed on 12/6/2017 8:34 AM CT
