Hi, I need to blow hot air to different liquids and measure the time needed to cool down each one of them. Currently, I’m using DS18B20 sensors to measure the temperature of the air and the liquids, but the hot air is being produced by a hair dryer (60°C), so I can’t set a different temperature. I thought I could replace the hair dryer with some power resistors and a DC fan like this one:
I would like to heat the air from 20°C to 30, 40 and 60°C. For example, to heat the air from 20 to 60°C I would need:
Q[W] = mairCpair (T2 - T1)
I get the air flow from the fan specs. 33 CFM = 0.016 m3/s = 0.018 kg/s @40°C
Cp(@40°C) = 1007 [J/kg/K]
T2-T1 = 40 K
Q= 0.018100740 = 725 W. I understand that this is the heat that the power resistors would dissipate but I don’t know how to supply that power (at 24V It requires 30A ). Any ideas on how to do it or am I doing the math wrong?. Thanks.