When you configure your Pelican web-app it asks for the zip code or postal code for your location. The devices uses that information to know where they are installed and to receive outdoor air saturation (humidity) and barometric pressure levels. The device uses its local outdoor dry-bulb temperature reading, in combination with the outdoor air saturation and barometric pressure levels to calculate local enthalpy.
This configuration can also be found and changed in the Pelican Web-App > Admin > Site Settings > Location.