A method for controlling a thermal conditioning circuit for an air flow , in particular intended for a passenger compartment of a motor vehicle, the circuit comprising a heat exchanger configured to be traversed by a refrigerant fluid and to exchange heat with the air flow , the heat exchanger being configured to operate selectively in at least: - a so-called cooling mode in which the air flow is cooled, - a so-called heating mode in which the air flow is heated, characterized in that the method comprises the steps of: - evaluating a level of humidity (H) in a region in contact with an outer surface of the heat exchanger , (step 60) - detecting a command to switch from the cooling mode to the heating mode, (step 61) - if the evaluated humidity level (H) is lower than a first predetermined threshold (s1), allowing the circulation of refrigerant fluid in the heat exchanger in response to the command to switch to the heating mode, (step 62) - if the evaluated humidity level (H) is higher than a second predetermined threshold (s2), preventing the circulation of the refrigerant fluid in the heat exchanger for a first predetermined duration (D1) in order to delay the switching to the heating mode, (step 63), wherein the second threshold (s2) is greater than or equal to the first threshold (s1). the circuit comprising a heat exchanger configured to be traversed by a refrigerant fluid and to exchange heat with the air flow , the heat exchanger being configured to operate selectively in at least: - a so-called cooling mode in which the air flow is cooled, - a so-called heating mode in which the air flow is heated, - a so-called cooling mode in which the air flow is cooled, - a so-called heating mode in which the air flow is heated, characterized in that the method comprises the steps of: - evaluating a level of humidity (H) in a region in contact with an outer surface of the heat exchanger , (step 60) - detecting a command to switch from the cooling mode to the heating mode, (step 61) - if the evaluated humidity level (H) is lower than a first predetermined threshold (s1), allowing the circulation of refrigerant fluid in the heat exchanger in response to the command to switch to the heating mode, (step 62) - if the evaluated humidity level (H) is higher than a second predetermined threshold (s2), preventing the circulation of the refrigerant fluid in the heat exchanger for a first predetermined duration (D1) in order to delay the switching to the heating mode, (step 63), - evaluating a level of humidity (H) in a region in contact with an outer surface of the heat exchanger , (step 60) - detecting a command to switch from the cooling mode to the heating mode, (step 61) - if the evaluated humidity level (H) is lower than a first predetermined threshold (s1), allowing the circulation of refrigerant fluid in the heat exchanger in response to the command to switch to the heating mode, (step 62) - if the evaluated humidity level (H) is higher than a second predetermined threshold (s2), preventing the circulation of the refrigerant fluid in the heat exchanger for a first predetermined duration (D1) in order to delay the switching to the heating mode, (step 63), wherein the second threshold (s2) is greater than or equal to the first threshold (s1). <EOS>