When fresh air is brought in for ventilation, what effect does it have during summer?

When fresh air is introduced for ventilation during the summer months, it brings in outside air, which is often warmer and potentially more humid than the indoor air. This influx of warm, moist air can significantly increase the indoor humidity levels, leading to a stuffy and uncomfortable environment within the building.

The cooling system may then need to work harder to remove this excess moisture from the air to maintain a comfortable indoor temperature, ultimately affecting the overall efficiency of the air conditioning system. By adding humidity to the indoor air, the fresh air can lead to discomfort and reduced efficiency of cooling equipment, potentially causing increased energy consumption as the air conditioning units strive to compensate for the added heat and humidity.

In contrast, while fresh air can help reduce indoor pollutants and improve air quality, that does not directly relate to the primary consequence of introducing warm, humid air during the summer. Additionally, fresh air does not typically enhance the efficiency of air conditioning systems but rather can have the opposite effect due to the increased load from higher humidity.