Q$5.($b$)$

A fire staircase pressurization system is used in shopping mall. The design pressure with all doors closed and all over pressure relief systems in operation shall be $50$ Pa minimum in accordance with BS$5588$ Part $4.$ The building information with details of the doors and the typical floor plan of escape doors are shown in Table Q$5\mathrm{.}1,$ Table Q$5\mathrm{.}2$ and Figure Q$5\mathrm{.}3$ respectively.

$($i$)$ Determine the total air leakage across remaining doors.

$(4$ marks$)$

$($ii$)$ Determine the design air supply flow rate for the pressurization system.

$(5$ marks$)$

$($iii$)$ State the multiple injection requirements with air supply and estimate the minimum number of injection points.

$(3$ marks$)$

$\backslash$table$[[$Type of building,:,Commercial building$],[$Floor$,$:$,$G$/$F$,1/$F to $13/$F & R$/$F $($each $3\mathrm{.}3$ m height$)],[$Staircases$,$:$,$No natural ventilation$]]$

Table Q$5\mathrm{.}1$ Building information

$\backslash$table$[[$Floor$,$Door type,Door Dimension $($m$),$Effective Leakage Area$],[$G$/$F Exit Door,$\backslash$table$[[$Double leaf door with or without center$],[$rebated frame$]],2\mathrm{.}21\mathrm{.}8,\backslash$table$[[0\mathrm{.}03m^2$