What is the difference between EER and IEER ratings on Commercial Rooftop Units?

EER (Energy Efficiency Ratio) and IEER (Integrated Energy Efficiency Ratio) are ratings used to measure the cooling efficiency of commercial HVAC equipment. EER measures how efficiently a unit operates under specific full-load outdoor temperature and operating conditions, while IEER evaluates efficiency across multiple operating conditions, including part-load performance. IEER provides a broader picture of how efficiently a commercial rooftop unit operates under varying cooling demands throughout the year. Higher EER and IEER ratings generally indicate greater energy efficiency and potentially lower operating costs.