MIL-PRF-12574 Refrigeration Units, Mechanical, Panel Type, 5000 Btu For Refrigerator, Field, Portable \(150 Cubic Foot\)This document covers two types of panel type, mechanical, refrigeration units having a capacity of 5000 British thermal units \(Btu\) per hour and used with a 150-cubic foot, portable field refrigerator \(see 6.1\).