In her budget reply speech on Thursday, LNP leader Deb Frecklington revealed her party's $1.5 billion plan to install airconditioning in every state school by 2028.

Currently, the government only funds airconditioning in state schools in tropical and western Queensland, with P&Cs; outside the "Cooler Schools Zone" forced to fundraise if they want to want airconditioning.

Education Minister Grace Grace called on the LNP leader to reveal how she would fund her promise.

"There are more than 32,000 classrooms at 1240 state schools in Queensland," she said.

"When the LNP were in office they rejected any proposal to fully fund airconditioning in all Queensland state schools."

Ms Grace pointed to then education minister John-Paul Langbroek's previous comments that it would cost $2 billion to install airconditioning in all Queensland state schools, plus $50 million annually for maintenance.

"At the time, he said there was 'limited money' and they had to 'try to balance a budget'," she said.

"Now the LNP is saying they will fully fund airconditioning in our schools, but where would they get the money to do that?

"What would they cut to fund their aircon promise?"

Ms Grace said $2 billion was more than double the annual infrastructure budget for state schools.

More than 380 state schools have already been airconditioned through the Cooler Schools program.

Ms Grace said the government partnered with schools across the state to help them reduce airconditioning costs through the Advancing Clean Energy Schools program and worked with schools and P&Cs; to find ways to install airconditioning outside the zone.