Qualifications AA degree from an accredited vocational technical or junior college EPA certification required Minimum 3+ years of experience in construction HVAC, Refrigeration, or a related industry Experience in troubleshooting electrical control systems is required Join Us Today, there are 27 different companies that make up the CoolSys family of brands. Sr, senior, Service Tech, refridgeration, HVAC, refrigeration, HVAC-R, HVAC/R, diagnostic, commercial, service, install, mechanical, mechanic, apprentice, AC, field service, chiller, specialist, HVACR, supermarket, rack systems.