Alfa Laval AlfaQ™ heat exchangers are used for HVAC applications such as district cooling substations, ice-storage systems, data centers, and free cooling systems. The range is certified according to the AHRI Liquid to Liquid Heat Exchangers (LLHE) Certification Program which ensures thermal performance according to manufacturers’ published specifications. AHRI certification is the only global, third-party performance certification for plate heat exchangers.