Dry-Type vs Oil-Immersed Transformers: 10 Key Differences and Selection Guide

10 Key Differences

1. Insulation: air/resin vs oil.
2. Cooling: convection/forced air vs oil circulation.
3. Fire risk: low vs requires controls.
4. Maintenance: minimal vs oil testing.
5. Cost curve: dry pricier small, oil cheaper large.
6. Indoor suitability: dry ideal, oil restricted.
7. Environmental: dry clean, oil leak risk.
8. Size: dry larger per kVA, oil compact.
9. Overload: oil better heat buffer.
10. Applications: buildings/IT vs substations/industry.

Quick Selection Table

Frequently Asked Questions

Is one more efficient?

Losses are comparable per design; oil edges out at very large ratings via better cooling.

How do I decide fast?

Start from location (indoor/outdoor) and rating — our guide does the rest.

Explore dry-type and oil-immersed product ranges to match your spec.