Currently there is no support for floating point output rasters in Raster Calculator Compression environment, as stated in the documentation:
"For the Compression environments, only the type of Compression is supported. This environment will only apply when the output would be of integer type. Compression is not supported on floating point rasters, so this environment will only apply when the output would be of integer type."
This is very problematic when working with large floating point rasters, since an additional compression step has to be taken.