School principal Steve Marshall said the fire caused about $100,000 damage.

“The good luck story to come out of this is that the year 12 artworks that had been in the room had been moved the previous day for an exhibition in the library, which was extremely lucky,” Mr Marshall said.

“What happened was just before recess on Friday; there was a strange noise coming from the air conditioner, it made a popping noise and a strange smell started to come out of it.

“The teacher in the room immediately got students out of classroom, and as it was recess all the students were outside playing and the room just caught fire,” Mr Marshall said.

Staff then tried to extinguish the fire from the outside with a fire extinguisher to no avail.

“It was a big air conditioner, and fire investigators told us because it was a fire in the circuit board it would have been impossible to contain, it just spread too fast,” Mr Marshall said.

It took the CFS just under an hour to extinguish the fire, and work has already started on getting the building ready for use again.

“The education department has been fantastic, they have been working all weekend cleaning up the room and we should be able to use it again by the end of the year,” Mr Marshall said.

Mr Marshall said staff and students had learnt from previous fire drills how to handle the situation.

“Everyone conducted themselves extremely well… the main thing is that no one was hurt,” he said.