Every transformer has an efficiency usually between 96% - 97%, which means is 4% or 3% of the transformer capacity (KVA) will convert to heat and dissipates into space. If the transformer has been installed in an electrical room (or any permitted room), the heat will raise the room temperature. The room temperature should be maintained below 80°F. If the room temperature exceeds 80°F, then a cooling system or ventilation system should be provided to keep the room temperature below 80°F.
For 4% heat dissipation:
200 KVA X o.8 X 4/100 = 6.4 KW
6.4 X 3140 = 20,096 BTUH
