Page 212 - Microsoft Word - 2_Inch_Drain_Adapter_PDS_2016_01_05

DURO-LAST PLENUM VENT
®
CALCULATIONS Note: It is the responsibility of the

To determine the amount of attic area covered per installing contractor of record to
vent, multiply the net free area (54 sq. in.) by either ensure that all applicable
150 or 300 sq. ft. (refer to IBC REQUIREMENTS on
page 1) and then divide by 144 sq. in. specifications, building codes,
To determine the quantity of required vents, divide regulations and ordinances are
the unconditioned attic space by the attic area per complied with and followed.
vent. Round up to the next whole number for any
fractional amounts.
VENTILATION REQUIREMENTS WITHOUT A VAPOR RETARDER
(144 SQ. IN. NET FREE AREA PER 150 SQ. FT.)
Unconditioned Unconditioned
Plenum Vent Attic Area per Number of Plenum Vent Attic Area per Number of
Attic Area Plenum Vents Plenum Vents
Net Free Area Vent without Required Net Free Area Vent with Eave Required
Eave Vents Vents
Sq. Ft. Sq. In. Sq. Ft. Each Sq. In. Sq. Ft. Each
100 54 56.25 2 54 112.50 1
200 54 56.25 4 54 112.50 2
300 54 56.25 6 54 112.50 3
400 54 56.25 8 54 112.50 4
500 54 56.25 9 54 112.50 5
600 54 56.25 11 54 112.50 6
700 54 56.25 13 54 112.50 7
800 54 56.25 15 54 112.50 8
900 54 56.25 16 54 112.50 8
1,000 54 56.25 18 54 112.50 9
1,100 54 56.25 20 54 112.50 10
1,200 54 56.25 22 54 112.50 11
1,300 54 56.25 24 54 112.50 12
1,400 54 56.25 25 54 112.50 13
1,500 54 56.25 27 54 112.50 14

VENTILATION REQUIREMENTS WITH A VAPOR RETARDER
(144 SQ. IN. NET FREE AREA PER 300 SQ. FT.)
Unconditioned Number of Unconditioned Number of
Plenum Vent Attic Area per Plenum Vent Attic Area per
Attic Area Plenum Vents Plenum Vents
Net Free Area Vent without Required Net Free Area Vent with Eave Required
Eave Vents Vents
Sq. Ft. Sq. In. Sq. Ft. Each Sq. In. Sq. Ft. Each
100 54 112.50 1 54 112.50 1
200 54 112.50 2 54 112.50 2
300 54 112.50 3 54 112.50 3
400 54 112.50 4 54 112.50 4
500 54 112.50 5 54 112.50 5
600 54 112.50 6 54 112.50 6
700 54 112.50 7 54 112.50 7
800 54 112.50 8 54 112.50 8
900 54 112.50 8 54 112.50 8
1,000 54 112.50 9 54 112.50 9
1,100 54 112.50 10 54 112.50 10
1,200 54 112.50 11 54 112.50 11
1,300 54 112.50 12 54 112.50 12
1,400 54 112.50 13 54 112.50 13
1,500 54 112.50 14 54 112.50 14

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Created: 11/08/2016