Unlimited Service Group, a division of Parts Town Unlimited, recently announced that it acquired Northsound Refrigeration and its sister company, Sound Refrigeration. Northsound Refrigeration is ba sed in Ferndale, Wash., and Sound Refrigeration in Mesa, Ariz. Northsound was founded in Bellingham, Wash., in 2001 and initially focused on servicing quick-service chains. It has since expanded…