The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) establish industry standards and certify product performance. AHRI’s certification programs use technical standards based on sound engineering practices to rate the efficiency of HVACR equipment as well as many other product attributes. Petra Engineering Industries Co. chilled water, hot water and DX coils in the Air Handling Units product range is certified by AHRI to AHRI 410 which means they are listed in the AHRI Directory of Certified Product Performance after successfully meeting stringent standards for product performance.