clearchris
30-04-2013, 12:26 PM
So I got tired of the cheap analog thermostats breaking in my cooler. I build a solid state one with an arduino (arduino.cc for the curious).
Why are the thermostat probes located in the evaporator coil? In my (short) experience, the coil temp doesn't have much to do with the cooler temperature. What I'm seeing is that the air leaving the evaporator is at 32F (0C) and the cooler air can be anywhere from 50F (out of spec) to 32F. So a reading in the coil isn't really helping me much.
Do the analog thermostats basically have a time delay built in? I.e. it takes maybe 15 mins for the gas in the probe to cool down thus ensuring that the circulating air has time to cool the contents?
Do you think I should
1) Build in a time delay (seems like a hack)
2) Move the thermocouple to a place that I want to actually measure the temperature.
I'm leaning towards #2 but I want to know why the thermocouple is in the coil. I imagine there must be a good reason for doing it this way.
Thanks!
Why are the thermostat probes located in the evaporator coil? In my (short) experience, the coil temp doesn't have much to do with the cooler temperature. What I'm seeing is that the air leaving the evaporator is at 32F (0C) and the cooler air can be anywhere from 50F (out of spec) to 32F. So a reading in the coil isn't really helping me much.
Do the analog thermostats basically have a time delay built in? I.e. it takes maybe 15 mins for the gas in the probe to cool down thus ensuring that the circulating air has time to cool the contents?
Do you think I should
1) Build in a time delay (seems like a hack)
2) Move the thermocouple to a place that I want to actually measure the temperature.
I'm leaning towards #2 but I want to know why the thermocouple is in the coil. I imagine there must be a good reason for doing it this way.
Thanks!