Question $3$

$($a$)$ A building in a city centre has a ventilation area totaling $1\mathrm{.}5m^2$ at a height of $30$ m on the windward face and a ventilation area totaling $0\mathrm{.}6m^2$ at the base on the leeward side. Only stack effect is considered $($wind effect ignored$).$ The internal temperature of $13C$ and the ambient air temperature is $22C.$ Calculate:

$($i$)$ The effective pressure difference for ventilation.

$($ii$)$ The ventilation flow rate.

Given: $R=287\mathrm{.}1$;$P_{\text{a}\text{t}\text{m}}=1\mathrm{.}01325{10}^5$;$C_d=0\mathrm{.}61$

$(10$ Marks$)$

$($b$)$ What are the design considerations for pipe in HVAC system?

$(7$ Marks$)$

$($c$)$ Suggest any THREE $(3)$ all$-$water system.

$(3$ Marks$)$