|Where can I find some simple explanation of why transformers don't dissipate heat properly when submerged. The transformers are 13.8 kV to 120/216. Rated 500 KVA. Impedance 5%. They are in underground vaults and generally are dry, however if pumps malfunction they can flood. The roof of the vaults are a solid slab with grates on either end. Ventilated area of grates is by design at least 3 CU per KvA of transformer. Sometimes side spacing is several feet to a wall sometimes only inches.