To support the operational safety of Soebali 2.0 (Sophisticated electron beam accelerator launched by Indonesia version 2.0), laboratory room condition with clean and dustfree, low temperature and humidity was required, and also maintained its stability using Air Conditioner (AC). In this regard, it was conducted to estimate the calculation of air cooling loads as a reference in determining the technical specification of AC that will be installed in Soebali 2.0 laboratory. Estimation was conducted to determine the air cooling loads that arise related to the construction of the building and supporting equipment for Soebali 2.0, which generates heat as the air cooling loads. Based on the estimation result, the total cooling capacity of the air conditioning system was about 153.585 BTU/hours or 15 kW. It was used for cooling the Soebali 2.0 laboratory room with 900 m3 of volume along with the operational supporting equipment was about 20 °C and relative humidity was 50 %.