Ventilation control device, ventilation system, and program

A ventilation control device configured, at predetermined intervals, to switch to a ventilation path in a building and to set a ventilation quantity of air passing through the ventilation path, the ventilation control device comprising:

• an information acquisition unit configured to acquire environmental information, the environmental information comprising:
• weather information comprising wind pertinent information about wind flowing outside the building, and air temperature and air humidity outside the building;
• and indoor environmental information comprising room temperature and room humidity in the building, the air temperature outside the building being an outside air temperature, the air humidity outside the building being an outside air humidity;
• a ventilation-path setting unit configured to set the ventilation path based on the environmental information acquired by the information acquisition unit;
• a ventilation-quantity setting unit configured to set the ventilation quantity based on the environmental information acquired by the information acquisition unit and the ventilation path that is set by the ventilation-path setting unit;
• and
• an output unit configured to output the ventilation path that is set by the ventilation-path setting unit and the ventilation quantity that is set by the ventilation-quantity setting unit,
• wherein the ventilation-path setting unit is configured:
• to set a plurality of candidate paths based on the environmental information, the plurality of candidate paths having priorities in descending order of expected ventilation effects;
• and
• in a case where a first candidate path having a highest priority of the plurality of candidate paths is identical with a previously set ventilation path, to set the first candidate path as the ventilation path, when a difference value between a room temperature previously acquired by the information acquisition unit and a room temperature presently acquired by the information acquisition unit is equal to or more than a predetermined threshold, and to set, as the ventilation path, a second candidate path having a second highest priority of the plurality of candidate paths, when the difference value is less than the predetermined threshold.