Nate Core Practice Test 2025 - Free Practice Questions and Study Guide

An air filter in HVAC systems serves the critical function of trapping airborne particles and pollutants. This includes dust, pollen, pet dander, mold spores, and other allergens that can compromise indoor air quality. By capturing these contaminants, the air filter helps maintain a clean and healthy environment within the space.

Moreover, a well-functioning air filter also protects the HVAC system itself by preventing debris from entering sensitive components, such as the evaporator and compressor, which can lead to reduced efficiency or even system failures over time. Regularly replacing or cleaning air filters is essential to ensure optimal performance and air quality.

While other options mention important aspects of HVAC system functions—like cooling air, regulating humidity levels, and circulating fresh air—they do not specifically address the filtering of air contaminants, which is the primary role of the air filter.