They are airconditioning companies. If you want to work commercial refrigeration, then you won't be going to the big national brands to work in that part of the field. I worked 13 years in a refrigeration shop, great learning experience. The large national brands work at a different pace and work attitude than a smaller refrigeration company.
I started in a refrigeration shop, learned/learning pretty much most types of equipment and installation practices, from 6oz. reach in coolers to multiple 100 ton refrigeration rack systems, to ice machines, to sheet metal fabrication, to condos, to chillers, to blast freezers, to boilers, to infrared heat, to etc. ad nauseum. Now I pretty much only work on large tonnage chillers. Learn as much as you can before settling down in one single part of the field.
Find a reputable company, learn from them and advance in your career with a goal in mind. If it becomes a chore to get up everyday then you know that that part of the field is not for you.