For the last three generations of kiosks, we’ve used these amazing solid-state air conditioners. They run on DC power, and they’re completely sealed to keep cement out of the kiosk. We have kiosks running in climates from -40 C (-40 F) to + 40 C (105 F) and quite a few in between!
The air conditioner needs very little maintenance. The important thing is to ensure that the heat exchange fins and fan are clear so that air can flow. Check the amount of dust built up around the fan and the fins and blow them down as required.