Which statement is correct about the importance of HVAC system sizing?

The importance of HVAC system sizing is crucial for achieving optimal performance and comfort. When a system is too large for the space it is intended to serve, it results in short cycling—where the system turns on and off frequently. This cycle does not allow the HVAC system adequate time to properly dehumidify the air, leading to increased indoor humidity levels. High humidity can create discomfort and contribute to mold growth, ultimately affecting indoor air quality.

In contrast, an HVAC system that is correctly sized will efficiently handle both temperature control and humidity levels, ensuring a comfortable environment. The other statements do not reflect correct principles of HVAC sizing; a system that is too small will not provide adequate cooling and may lead to increased operational costs over time. Additionally, system sizing significantly impacts operational costs—an oversized system could lead to higher energy bills, while an undersized system may require additional energy and repairs. Finally, the idea that a larger system will always outperform a smaller one is misleading, as efficiency and effectiveness depend on proper sizing relative to the specific requirements of the space.