Can anyone recommend an industrial HVAC company servicing the Chicago area ?

Looking for a reputable HVAC company to service on central A/C in a 15,000 square foot home. (Hopefully, someone who does not see dollar signs when they see the home...)

Listen Michelle you need to specify more, ok. Are you looking for a reputable company to do work on your home system. Or are you talking about HVAC as in for a company, hospital, school, commercial bldg, manufacturing bldg etc.
Another tip; all industrial companies should and will be SMACNA professionals ( Sheet Metal and Air Conditioning Contractors National Association Inc.
The reason I'm asking for more info is this is my field, and I can best advise when I know what type of client we are talking about.
My credentials are as a degreed engineer who has twelve years in contruction and more as an engineer. I build hospitals, schools, and universities.
I would suggest the name brand companys you airhandler is; such as York or Carrier because they have the most outlets regionally. A call to one of their company offices and they will give you the name of a repair / installer in your area. I am assuming you want the system checked out, serviced and a initial start-up running. So that during the season there are no problems.
Here are a few other companies, cannot honetly tell you their cost;
IMI (IndependentMechanical Industries,Inc- 773-282-2046
they are in Chicago on Montrose Ave.
C&W Sheetmetal Inc. -773-622-8757 on North ave.
Even if you don't use these people, try and get three estimates to choose from. ask them if the estimate is free. Also remember you can and should ask neighbors who they use too. You want an overall cost not time and materials because thats the most expensive. There will be a lobor charge but should your system need parts it should be standard with parts and assemblies right off the shelf. Good luck