We report here DFT-based ab initio Molecular Dynamics results of water confined in a large pore LTA hydrophobic zeolite. We have studied the molecular dipole of confined water molecules, hydrogen bonding properties, and we have computed the system infrared spectrum. It is found that the infrared spectrum of the structural zeolite is decorrelated from the confined water zeolite indicating very small interaction between the host and the guest species. This is confirmed by the study of hydrogen bonds which showed the absence of genuine water-zeolite hydrogen bonds. The water OH-stretch band shows similar shape and frequency with respect to bulk water, except for a narrow peak at 2300 cm-1 attributed to OH bonds directed towards the zeolite. The lifetime of water-water hydrogen bonds in confined water is found to be similar to those in bulk water, indicating a similar H-bond strength within confined water. Finally, we observe a slight decrease of the water dipole moment with respect to its bulk value. The resulting dipole moment is, however, still largely enhanced with respect to its gas phase value, due to hydrogen bonding.