An experimental investigation into the effects of pressure and subcooling on the pool boiling critical heat flux from a bare silicon chip-like heater and from a silicon heater coated with microporous layers, is reported. The dual inline heater package was immersed in FC-72, a dielectric fluid, and the experiments were performed in the horizontal orientation, with subcooling varying between 0 K and 72 K, and the pressure between 101.3 kPa and 303.9 kPa. The maximum CHF values on the diamond-base microporous-coated silicon heater were found to reach 47 W/cm(2), at 3 atm and nearly 50 K of subcooling, and to provide an average enhancement of approximately 60% over the values attained with un-treated silicon surfaces. An available CHF correlation, with a reported standard deviation of 12.5% for untreated surfaces over a large range of pressures, subcoolings, and surface conditions, was shown to predict the pressure and subcooling effects on CHF from the surface-enhanced chip with a standard deviation of 12%. (c) 2006 Elsevier Ltd. All rights reserved.