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5.3.1.1.1 Water temperature vs. heating element setting
Figure 5.16 shows the humidifier water temperature when the humidifier heating
element temperature setting changes. It can be seen that when heating element
temperature setting is high, the water temperature is also high.
Figure 5.16 Comparison of model outputs and experimental results of humidifier water
temperature vs. heating element temperature setting under normal ambient room temperature and
pressure setting at 12cmH2O
5.3.1.1.2 Water temperature vs. CPAP pressure setting
Figure 5.17 shows the water temperature under normal room temperature and
humidifier heating element setting of 55°C. The tests were conducted on different days
and the room temperature and relative humidity level were not exactly the same.
However, still the trend is maintained. It can be seen that when pressure setting is high,
the water temperature becomes lower. This is because the higher the pressure setting is,
the higher the mass and heat convections and consequently the more heat energy is lost
from the water to the air above it.
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