Apollo Command Module (Block II) Environmental Control Unit (ECU) Evaporator, measuring 13 x 8 x 6, stenciled on one side with part numbers, “812582-10 Assy. DWO 93922, SN 41.” In fine condition. One of two evaporators used to cool water-glycol mixture circulated within the Apollo Command Module. The glycol loop removed waste heat from astronaut space suits and supported temperature control of spacecraft atmosphere. Two of these evaporators, one for the primary and the other for the secondary coolant system, are made of special corrosion-resistant stainless steel plates and fin passages for the water-glycol arranged in a series of stacks alternated with sintered felt metal wicks, which were fed water through a plate with tiny holes. Evaporation cooled the plates which in turn cooled the water-glycol passing through, allowing the removal of excess heat at a rate of about 8,000 BTU per hour. A necessity for maintaining comfortable conditions for astronauts as they journeyed through space.
