5._Building_Pressure_Calculation.pdf

Client: RAFI Architecture

Project: NASA Hangar B4802

Project No.: 14118.00

Date:

Calculation: Building Pressure Calculation

Page: 1 of 1

WALLS: A/AW = 0.00100 Where:

EXIT ENCLOSURES: A/AW = 0.00035 A = TOTAL LEAKAGE AREA, SQUARE FEET

ALL OTHER SHAFTS: A/AW = 0.00150 AF = UNIT FLOOR OR ROOF AREA OF BARRIER, SQUARE FEET

FLOORS AND ROOFS: A/AF = 0.00050 AW = UNIT WALL AREA OF BARRIER, SQUARE FEET

Supply Rate: Q = Kf A e∆P Where:

Q = VOLUMETRIC FLOW RATE, CUBIC FEET PER MINUTE

A = FLOW AREA (ALSO CALLED LEAKAGE AREA), SQUARE FEET

∆P = PRESSURE DIFFERENCE ACROSS PATH, INCHES WATER GAUGE

KF = COEFFICIENT, 2610

ENTER:

FLOOR AREA: 0 sq. ft.

ROOF AREA: 57,871 sq. ft.

WALL AREA: 30,600 sq. ft. Three walls - 680 LF x 45 H

EXIT SHAFT WALL AREA: 0 sq. ft.

OTHER SHAFT WALL AREA: 0 sq. ft.

OTHER OPENINGS: 118 sq. ft. Hangar Doors - 356 LF x .166 (2") x 2 doors

NUMBER OF 36-INCH DOORS: 0 doors Ave. Height of Doors: 80 Inches

NUMBER OF 42-INCH DOORS: 0 doors

NUMBER OF 48-INCH DOORS: 0 doors

Pressure Differential Required: 0.05 Inches Water Gauge

Leakage Area of Floor: 0.00 sq. ft.

Leakage Area of Roof: 28.94 sq. ft.

Leakage Area of Walls: 30.60 sq. ft.

Leakage Area of Exit Enclosures: 0.00 sq. ft.

Leakage Area of Shafts: 0.00 sq. ft.

Leakage Area of Other Openings: 118.00 sq. ft.

Leakage Area of Doors (1)

: 0.00 sq. ft.

Total Leakage Area: 177.54 sq. ft.

Outside Air Required: 103,612 cfm

For a Pressure Differential of: 0.05 Inches Water Gauge

(1)

Door Openings based on 1/4-inch gap at bottom and 1/16-inch gap at top and both sides since seals are provided on top and sides.

Assumes average height of doors throughout.

March 4, 2016

Pressurization Method Calculations 3/4/2016