Tutorial Problems

Saturated water vapour at $100C$ is used to humidify a stream of moist air. The air

enters the humidifier at $13Cdb$ and $5C$ wb at a flow rate of $3k\frac{g}{s}.$ The pressure is

$101\mathrm{.}3$ kPa $.$ Determine

$($a$)$ the mass flow rate of the steam required to saturate the air; and

$($b$)$ the temperature of the saturated air.

$($Ans$.0\mathrm{.}0243k\frac{g}{s},14\mathrm{.}3C)$

A room has a design sensible heat ratio of $0\mathrm{.}84.$ Cool air at $14C$ and $90\%RH$ is

supplied to the room to maintain it at $24C.$

Sketch the room ratio line through the supply air state on the psychrometric chart,

hence determine the resulting relative humidity and moisture content in the room. $[$Do

not use the SHR protractor. It is not accurate in using it$.]$

$($Ans$.0\mathrm{.}0098k\frac{g}{k}g$ dry air, $52\%)$