Priests of elemental air or elemental water can summon elementals from their respective spheres, just as druids can conjure fire or earth elementals. The summoned elemental is 60% likely to have 12 Hit Dice, 35% likely to have 16 Hit Dice, and 5% likely to have 21 to 24 Hit Dice (20+1d4). Unlike the wizard version of this spell, the caster does not need to concentrate to maintain control of the elemental since the creature regards the caster as a friend and obeys him implicitly. The elemental remains until destroyed, dispelled, sent away by a dismissal or a holy word spell, or the spell duration expires.
Priest's Spell Compendium Text
See conjure air elemental (7th) and conjure water elemental (6th) (PO:SM).