Energy recovery ventilators (ERVs) have been utilized within air conditioning systems to enhance energy efficiency and to improve indoor air quality. ERV performance contributes significantly towered lowering electrical consumption and emissions of the installed systems. Annual energy savings resulted from integrating a hybrid flow ERV to a conventional HVAC system is numerically investigated in the current research. Thermal performance of air to air ERV is estimated with the aid of computational fluid dynamics (CFD) approach, and the average annual energy consumption of the simulated building is estimated using hourly analysis program (HAP) software at different locations worldwide. Based on CFD simulations, a correlation for the total effectiveness of the ERV was developed (εt = 4.2�TR0.06377Re�0.29458) which is a function of dry and wet bulb temperature at design conditions of a given location (�TR) and Reynolds number (Re) of air flowing through the ERV. Furthermore, CFD simulations showed that the amount of latent energy recovered could be as high as 6 times the amount of sensible energy recovered as the ambient conditions approaches the tropical humid conditions or as �TR decreases. Building simulations using HAP showed that the ERV has reduced the size of the cooling/heating coils which resulted in lowering the electrical energy needed to run the HVAC equipment. Utilizing the ERV could also contribute to coil downsizing of up to 40.5 kW, a total electrical load recovery of up to 8648 kWh and RER values of up to 662 for tropical cities such as Singapore. Moreover, an up to 16,000 kgCO2e could be reduced with an annual cost saving of up to US3000 when adopting the ERV unit. Therefore, it is recommended to design the ERV to serve at relatively low Re values which reflects on obtaining higher effectiveness, lower pressure drop and the greatest possibility for energy recovery. © 2020, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.