A space is to be maintained at $25$C dry bulb and $20$C wet bulb temperatures.

The cooling system is a variable$-$air$-$volume $($VAV$)$ type where the volumetric flow rate of

air supplied, and the supply air temperature, are controlled in response to changing load

conditions. Under design conditions, the total cooling load is $150$ tons, with a sensible heat

factor of SHF $=0\mathrm{.}6,$ and the supply air temperature is $15$C$.$ At the minimum load of $18$ tons

with SHF $=0\mathrm{.}8,$ the volumetric air flow rate supplied to the space is $20\%$ that of the full$-$load

design value. Determine the supply air conditions for minimum load, in terms of the dry$-$bulb

and wet$-$bulb temperatures