Gov. Linda Lingle has released $19.57 million for improvements to the air-conditioning at Honolulu International Airport as part of a $2.3 billion, 12-year airports modernization plan.

The project is being coordinated with other projects that will link the airport's major air-conditioning systems in order to save on energy costs, improve operational efficiency and add needed system redundancy at the airport, according to a news release from Lingle's office yesterday.

Once completed, there will be three chiller plants capable of cooling the Overseas Terminal's three concourses and the Inter-Island Terminal, as well as future airport expansions, according to the release.

The new chiller plants will be at the Overseas Terminal and Diamond Head and 'Ewa concourses, respectively, and will be connected through a common chilled water loop.

Construction of the new Diamond Head chiller plant and the connective chilled water loop are near completion, which will allow the air-conditioning needs of the airport's Overseas and Inter-Island terminals to be met while this next phase moves forward. This project includes demolishing the existing Overseas Terminal chiller plant and renovating surrounding areas to accommodate a new, larger plant.

The $19.57 million released by Lingle is part of a total $21.8 million budgeted for the current phase of the project. The 'Ewa Concourse chiller plant will be replaced during the next phase. A future project will also replace the Commuter Terminal chiller.

Separately, U.S. Rep Mazie K. Hirono yesterday announced that the U.S. Department of Transportation has approved $5.88 million for improvements to the Lihu'e Airport on Kaua'i and the Hilo International Airport on the Big Island.

The bulk of the money — $5.7 million in federal funds will go toward replacing the heating, ventilation, and air-conditioning system at the Lihu'e Airport.

Funds also will be used to install a noise monitoring system at the Hilo International Airport.