Part$-1$

A fan is to be selected to ventilate a room which has air velocity of $8$

m$/$s$.$ The combined efficiency of the fan$$motor unit to be used can be

taken to be $65$ percent. Given room dimensions are $4$ m $\backslash$times $2\mathrm{.}5$ m $\backslash$times $3$ m$.$

If the the fan is to replace the entire volume of air in $9\mathrm{.}5$ min,

Determine:

$($a$)$ Power of fan$$motor unit to be purchased

$($c$)$ The diameter of the fan casing.

Take the air density to be $1\mathrm{.}2$ kg$/$m$3$ and disregard the effect of the kinetic energy correction factors

Part$\mathrm{.}2$:

Heated air at $1$ atm and $30\backslash$deg C is to be transported in a $105$ m$-$long

circular plastic duct at a rate of $0\mathrm{.}8$ m$3/$s$.$ If the head loss in the pipe is

not to exceed $17$ m$,$ determine the minimum diameter of the duct.

$($Use a proper table to find air properties if necessary$)$