Experimental techniques for determining heat and mass transfer due to condensation of humid air in cooled, open cavities

An experimental investigation was conducted to examine combined buoyancy driven heat and mass transfer in open cavities of different aspect ratios. Test cavities were constructed with calorimeter plates bonded to Styrofoam insulation. The inside of the cavities was cooled and then exposed to ambient air for approximately 17–30 min. Measurements were conducted at three initial cavity temperatures (5 °C, 1 °C, and −5 °C) each for a range of ambient relative humidity from 60% to 75%. The mass of retained condensate accumulated on the inside cavity walls and the transient cavity temperatures were measured. The mass flux of retained condensate inside the cavity was compared to the mass flux determined utilizing the heat/mass transfer analogy. The results between the two methods were in good agreement. The effects of the retained condensate on the mass flux measurements due to the water’s thermal resistance and surface emittance were also investigated and shown to have a negligible impact.