In HVAC systems, what do we refer to as 'infiltration'?

In HVAC systems, infiltration refers to the process of air leakage into a building, which occurs through gaps, cracks, and openings in the building envelope. This can include windows, doors, and walls, where unconditioned outside air enters the structure. Understanding infiltration is crucial because it affects the overall energy efficiency and comfort levels within a building. When unconditioned air infiltrates, it can lead to an increase in heating or cooling demands, causing the HVAC system to work harder to maintain desired indoor temperatures.

In contrast, the other options do not accurately describe infiltration. For example, the maintenance of air pressure pertains more to the balancing of systems to ensure proper airflow without considering unintentional air leaks. Similarly, the methods of conditioning air are about actively treating the air within the system, and controlling indoor climate pertains to managing factors such as temperature, humidity, and air quality, which goes beyond just the concept of infiltration. Understanding how infiltration affects HVAC performance is essential for optimizing energy efficiency and indoor comfort.