Measuring Temp & Humidity in the Root Cellar

Now that the door is in place, we can see how well the root cellar in the shed is maintaining the desired temperature and humidity conditions.

I hacked together a quick temperature and humidity sensor (pictured left) that could log data records to an SD card (using the DHT22 sensor from Adafruit connected to an Arduino) and used it to collect data from approximately 7:30am CT yesterday through about 5:30 am today.

Here’s the data in the root cellar (pardon the ugly axis labels):

And here’s the same data from outside over the same time range (via weatherspark.com):At a glance, I think this is a good result.  Both temp. and relative humidity were held much more stably in the cellar than outside.  Temp stayed almost 10 degrees F below the outside temp, and humidity stayed high in the cellar when it dropped outside during the afternoon yesterday.

This needs further study, and in particular I’m concerned that the cellar is warmer than ideal right now, but I think we’re on the right track.