Energy recovery ventilators (ERVs) are designed to improve HVAC system performance by taking the energy from exhausted building air and using it to precondition incoming outdoor ventilation air. This preconditioning reduces the load demand on the HVAC unit while significantly lowering energy costs. When specifying an ERV, there are several factors that can help determine the optimal unit for the application. Functional and performance features are important, but considerations for installation, maintenance, and even long-term durability should not be overlooked.