The energy saving potentials of zone-level membrane-based enthalpy recovery ventilators for VAV systems in commercial buildings

Enthalpy recovery ventilators exchange heat and mass between exhausted air and outdoor ventilation air to reduce mechanical ventilation loads for HVAC systems in buildings. This study demonstrates the energy saving potential of integrating membrane-based energy recovery ventilators at zone-level into the conventional variable air volume (VAV) systems for commercial buildings. Building energy simulations are used to evaluate various operation strategies and potential energy savings for four selected climates including Minneapolis, Atlanta, Baltimore, and Miami. A medium-size DOE reference commercial building model with conventional VAV systems was used as a baseline. Three cases implemented with energy recovery ventilators were simulated using EnergyPlus and their results were compared with baseline cases in compliance with ASHRAE standard 90.1. The annual HVAC energy saving potential can reach up to 18-49% with this technique for various climates. The challenges of implementing and operating the zone-level energy recovery ventilators are also discussed in this paper.