$3-52.$ Under normal operating conditions a zone has a total cooling load of $120,000Bt\frac{u}{h}r(35kW)$

with a SHF of $0\mathrm{.}8.$ The space is to be maintained at $74F(23C)db$ and $50\%$ relative humidity

$(RH).$ However, there are periods when the latent load is high and the SHF is estimated to be

as low as $0\mathrm{.}6.$ Assume that air enters the cooling coil at $85F(29C)db$ and $71F(22C)wb$ and

the coil apparatus dew point is $48F(9C).($a$)$ Devise a system and the associated psychro$-$

metric processes to cover the necessary range of operation. $($b$)$ Define the various air states and

show the processes on Chart $1$a$.($c$)$ Compute air$-$flow rate, coil load, minimum zone load, and

anv reheat that mav be required. Assume constant air flow and standard sea$-$level pressure. Please solve only a and b