An air conditioning system having a plurality of air conditioners installed in a predetermined place and an operation terminal configured to communicate with the air conditioners by radio signals, wherein, each of the air conditioners comprises a first radio communication unit configured to send a beacon signal, the operation terminal comprises: a second radio communication unit configured to receive two or more beacon signals sent by two or more air conditioners of the air conditioners; and a location presumption unit configured to presume a current location by using two or more radio wave intensities measured from each of the two or more beacon signals and a last location, the current location being a location in which the operation terminal is currently located, the last location being a location presumed last as a location of the operation terminal, wherein the location presumption unit is configured to set a plurality of predetermined candidate locations within a predetermined range from the last location, select, from the plurality of candidate locations, one candidate location having two or more distances calculated for each of the two or more air conditioners best matching the two or more radio wave intensities, and presume the one candidate location as the current location. each of the air conditioners comprises a first radio communication unit configured to send a beacon signal, the operation terminal comprises: a second radio communication unit configured to receive two or more beacon signals sent by two or more air conditioners of the air conditioners; and a location presumption unit configured to presume a current location by using two or more radio wave intensities measured from each of the two or more beacon signals and a last location, the current location being a location in which the operation terminal is currently located, the last location being a location presumed last as a location of the operation terminal, wherein the location presumption unit is configured to set a plurality of predetermined candidate locations within a predetermined range from the last location, select, from the plurality of candidate locations, one candidate location having two or more distances calculated for each of the two or more air conditioners best matching the two or more radio wave intensities, and presume the one candidate location as the current location. a second radio communication unit configured to receive two or more beacon signals sent by two or more air conditioners of the air conditioners; and a location presumption unit configured to presume a current location by using two or more radio wave intensities measured from each of the two or more beacon signals and a last location, the current location being a location in which the operation terminal is currently located, the last location being a location presumed last as a location of the operation terminal, wherein the location presumption unit is configured to set a plurality of predetermined candidate locations within a predetermined range from the last location, select, from the plurality of candidate locations, one candidate location having two or more distances calculated for each of the two or more air conditioners best matching the two or more radio wave intensities, and presume the one candidate location as the current location.