Abstract
Several thermomodules were selected from the family of miniature thermo-electric heat pumps in modular form, to investigate their performance to condense water from laboratory room air by cooling.
The efficiency to get condensed water was mainly restricted by the low heat conversion at the cooling surface (Fig. 7) . The highest efficiency was obtained when the cold surface temperature was set about 8°C cooler than the dew point (Fig. 5) .
The dew point control using a thermomodule was also studied on a model house, composed of vinylfilm and wood frames of 61 cm in hight, 45 cm in width, 45 cm in length.
Dew point and house temperature were measured in the center of the house containing a plant pot from which the evapotranspiration was fed with the rate of 0.5-2 cm3per hour at the temperature of 23-27°C.
A simple on-off controller was constructed to control the electric current to the thermomodule by the action of a power relay which was activated by a signal from the dew point transducer (Fig. 3) .
This system performed the control of dew point within ± about 0.5°C at the dew point range of 20-14°C (Fig. 8) .
