I know they are part of the same parent company, but each brand has a Web site and the model(s) I'm looking at have different model numbers. I'm going to call the company and ask but thought I could get a quicker answer here. I am changing out a 3 ton package unit. The Trane Model is TCH036 and the Amer Std is something different (until you click on the specs and its listed as TCH036). The reason I ask is because I am getting quotes all over the map. I understand the big difference b/twn a solo practitioner and the companies with the fleets of sales/service people. But two of these fleet companies quote a $900 difference in price for the job. One identifies the unit going in as Am Std and the other Trane. I realize they probably used to have different distributors/dealers before they merged, but I wonder whether I am getting the exact same parts on each model. Since I understand that Trane actually manufactures compressors, I'd go with them. But does that mean I can pick the Amer Std brand (with the $900 cheaper price)and get the same goods? Regards. SE FL Customer