It is effective when ventilation is increased to prevent viral infection such as COVID-19 indoors. However, an increase in the amount of ventilation inevitably increases the consumption of heating and cooling energy. In this study, the change in energy consumption was estimated when ventilation was increased to prevent COVID-19 infection using the eQUEST prototypical office building model and typical weather data files developed by Chungbuk National University. As a result of the simulation, when the ventilation rate standard of the building increased by 5%, the rate of increase in energy consumption increased by 3.98% in the Central 1 area, 3.81% in the Central 2 area, 2.76% in the Southern area, and 2.15% in the Jeju area. In the next step, after applying heat recovery ventilator (ERV) to minimize the increase in energy consumption due to the increase in ventilation, when the ventilation rate increases by 5%, 0.99% in the Central 1 region, 0.96% in the Central 2 region, 0.58% in the Southern region, and 0.57% in the Jeju region. According to the experimental results, if the ventilation rate is increased by 5% compared to the existing ventilation rate regulation, the annual energy consumption increases by about 2~4% depending on the climate region. However, if ERVs are installed, it is estimated that the virus infection rate can be reduced by recovering most of the energy due to the increase in ventilation and consuming less than 1% of additional energy per region.