Carbon tetrachloride flowing at 19.000 kg/h is to be cooled from 85 to 40°C using 13.500 kg/h of cooling water at 20°C. The film coefficient for carbon tetrachloride, outside the tubes, is 1,700 W/m² · °C. The wall resistance is negligible, but h_i on the water side, including fouling factors, is 11,000 W/m² · °C. 

(a) What area is needed for a counter flow exchanger? 

(b) By what factor would the area be increased if parallel flow were used to get more rapid initial cooling of the carbon tetrachloride?