The big chill is coming to Union Station

Those giant fans Union Station commuters are only too familiar with every summer will be replaced with a welcome innovation -- air conditioning -- in the not-too-distant future.

Amtrak officials joined by state and federal lawmakers on Monday announced $40 million in renovations to the venerable Chicago station, which handles about 50,000 passengers a day.

The upgrades include air-conditioning the Great Hall by summer 2011. Amtrak officials said the improvements will increase opportunities to use the Great Hall for events in the summer, make the site more attractive to tenants and allow the company to move its regional offices there. More washrooms will be installed in the concourse area.

By 2012, Amtrak coach and business-class passengers will also see better days with the doubling of seating in lounge areas from 450 seats to 950. A lounge serving overnight, long-distance travelers will be moved to accommodate 50 more seats.

The work is expected to generate about 100 construction jobs.

Amtrak has contracted with real-estate firm Jones Lang LaSalle to come up with a redevelopment plan for the building.