Method for controlling an air-flow thermal conditioning unit

A control method for controlling a thermal conditioning circuit for thermally conditioning an air flow for a passenger compartment of a motor vehicle, the thermal conditioning circuit comprising a heat exchanger configured to have a refrigerant pass through it and to exchange heat with the air flow, the heat exchanger being configured to operate selectively in at least:

• a cooling mode in which the air flow is cooled,
• a heating mode in which the air flow is heated,
• the control method comprising:
• evaluating a moisture level in a region in contact with an outer surface of the heat exchanger;
• detecting an instruction to switch from the cooling mode to the heating mode;
• allowing the refrigerant to circulate through the heat exchanger in response to the instruction to switch to the heating mode, wherein the evaluated moisture level is below a first predetermined threshold;
• and
• preventing the refrigerant from circulating through the heat exchanger for a first predetermined period of time so as to delay the switch to the heating mode,
• wherein the evaluated moisture level is above a second predetermined threshold,
• wherein the second predetermined threshold is greater than the first predetermined threshold;
• wherein the thermal conditioning circuit comprises an additional heater configured to heat the air flow, and
• wherein preventing the refrigerant from circulating through the heat exchanger for the first predetermined period of time further comprises activating the additional heater to heat the air flow.