Which ventilation system is designed to equalize indoor and outdoor air?

A balanced ventilation system is specifically designed to equalize the indoor and outdoor air by providing an equal volume of fresh air into the space while simultaneously exhausting an equal volume of stale air. This type of system ensures that there is neither a negative nor a positive pressure created within the building, which is crucial for maintaining air quality and preventing issues such as drafts or moisture accumulation.

In contrast, an exhaust system primarily removes indoor air without bringing in an equal volume of outdoor air, which can lead to negative pressure. A supply system introduces outdoor air into the building but may not effectively remove an equivalent amount of indoor air, potentially leading to an imbalance. A makeup air system addresses the need for fresh air intake but typically works in conjunction with an exhaust system and does not guarantee an equal exchange with the outdoor air. Thus, the balanced system stands out as the correct answer, as its core function is to maintain an equal exchange of air, promoting optimal indoor air quality.