Which of the following factors can lead to increased pressure in an HVAC system?

Increased pressure in an HVAC system can be primarily attributed to the presence of excess non-condensables. Non-condensables are gases that do not change phase during the refrigeration process, such as air and other contaminants that can enter the system. When these gases accumulate in the refrigerant lines or evaporator coils, they take up space that would typically be occupied by refrigerant vapor. This leads to an increase in the overall pressure within the system.

Maintaining proper refrigerant levels is crucial for efficient operation, and when non-condensable gases are present, the system struggles to maintain optimal conditions, which can cause pressure spikes. This condition can eventually lead to reduced efficiency, potential damage to the compressor, and other operational issues. Identifying and removing non-condensables is therefore a vital part of HVAC maintenance to ensure the system operates within the designed pressure ranges.