If you have already seen our ‘Datalogging: The cooling effect of evaporation‘ post, you may remember that we had stumbled across something interesting, that we wanted to investigate further. The temperature inside the cups increased when we turned the fan on.
We came up with a hypothesis. We believe that the fan caused the air to circulate around the room, mixing the warmer air from the top of the room, with the cooler air, towards the bottom. The cups were placed on a shelf in the lower half of the room, so this may explain what was going on.
To test our theory, we placed two dataloggers in the room. One on the top shelf of the unit, and the other in the middle, where the other investigations took place. We decided to leave the dataloggers recording for a while in the room before turning the fan on.
Our results turned out wonderfully. The temperature inside the room was gradually increasing, and the datalogger on the top shelf increased more than the other one. This is due to the fact that it was placed around 30cm away from a light, which will warm up the air around it.
Not long after the fan was turned on at 12:30, the temperatures began to change. The top shelf datalogger cooled down, and the datalogger on the middle shelf warmed up. The fan both warmed and cooled areas of the room simultaneously!
This result perfectly supported our hypothesis.