In this work, virion concentration and its dose changes by HVAC and air cleaners were estimated in a subway station platform to control airborne infection of SARS-CoV-2. Collection efficiencies with particle size were measured for the air filter equipped in a HVAC in one subway station in Daejeon. Indoor PM2.5 changes according to outdoor PM2.5 with time were also measured to estimate air infiltration rate in the subway station platform. When infected persons generate virions by 104, 105, 106, 3 x 106 and 5 x 106 h-1 in a 2,400 ㎥ volume platform, the concentration and dose were estimated as 9, 92, 275 and 458 virions/㎥ and 4, 43, 130 and 217 virions after 1 hour exposure, respectively. The concentration and dose were reduced by 70%, and 64%, respectively by operations of both HVAC (with a flow rate of 16,000 ㎥/h, MERV 11) and ten air cleaners(with total CADR 10,740 ㎥/h) compared to those without operation of both HVAC and air cleaners. However, virion dose in the platform was estimated to be too low at the general conditions due to a large space, a high air infiltration (3 h-1) and a short residence time (usually < 10 mins) in the platform irrespective of the operations of HVAC or air cleaners. HVAC with filters and air cleaners would be more necessary in the concourse or shopping areas in the subway stations to reduce the infection dose from a few hundred to several tens virions in a hour.