Experimental studies of single-phase heat transfer with the working fluid FC-72 from a single chip and a four-in-line chip module mounted on one wall of a vertical rectangular channel are carried out. Both flush-mounted and protruding chip configurations are investigated with the channel height being equal to the ship length. The Reynolds number based on chip length ranged from 2.2 x 10(3) to 6.3 x 10(4) (3.0 x 10(3) < Re-D < 8.4 x 10(4)) for an inlet temperature of 25 degrees C. Results for a single flush-mounted chip are in good agreement with those obtained for the most upstream chip of the multichip module. Heat transfer data of a single heated protruding chip located downstream agree well with the results from the single flush-mounted chip. Heat transfer coefficients from flush-mounted chips are less than those from protruding chips.