Some maps have dry ice while others have water ice. The resource ice condensers produce is based on the type of ice on the map.

Dry ice = Carbon and oxygen.

Water Ice = Water.

In the campaign it tells you which type of ice is on a map before you select the map to play on. Outside of the campaign you should pay attention to whether the ice condenser appears under water or under carbon and oxygen. Once you get better you should be able to tell just by the appearance whether it's dry ice or water ice.

TL;DR: It depends on the map whether you get ice or dry ice.