Theoretically, there is no area where dry-type transformers cannot be used. However, there are numerous different design criteria that would need to be considered depending on the application conditions.
Extreme Temperatures: Dry-type transformers can be designed to operate in extreme temperatures but may require a specific cooling design (for hotter than usual conditions) and external heating (for colder than usual conditions).
Corrosive Environments: Some dry-type transformers are not designed to resist corrosive environments, such as those found in chemical or saltwater environments. In these conditions, corrosion-resistant materials or specialised coatings may be required as well as custom designed enclosures
Severe Vibration: Dry-type transformers are designed to withstand some level of vibration, but severe vibrations can cause structural damage and impact performance. In applications with severe vibration, specialised transformers may be required.
High Altitude: Dry-type transformers are designed to operate at 1000MASL as a standard, and high altitudes can impact their performance. In high-altitude environments, specially designed transformers are required.
It is important to consider these environmental conditions and consult with an experienced electrical engineer to determine the best solution for a particular application. The suitability of dry-type transformers for a particular environment will depend on the specific conditions, requirements, and the specific design and specifications of the dry-type transformer being considered.