Dry type transformers find use in locations where it is not possible to use oil-filled transformers such as shopping malls. Hospitals, residential complexes, etc due to the risk of fire. In dry type transformers air is used as the cooling medium instead of oil.
The insulation used in dry type transformers is designed to withstand higher temperatures. Dry type transformers are thus more expensive than conventional transformers Vacuum Pressure Impregnation, Epoxy Resin cast are some of the methods of Insulation adopted in dry-type transformer construction.
The downside of the dry type transformers is that the efficiency of these transformers is lower than that of conventional transformers. Dry type transformers cannot be designed for very high voltages and are designed only upto the MV range.