When high-side pressure readings are affected in an HVAC system due to trapped air, which law is applied?

The correct answer is based on Dalton's Law, which is fundamental in understanding how gases behave in a mixture and how pressure is affected by the presence of different gases, including air. Dalton's Law states that in a mixture of gases, each gas exerts its own partial pressure independently of the others, and the total pressure is the sum of these partial pressures.

In the context of an HVAC system where there is trapped air, the presence of air increases the total pressure on the high side of the system. The air mixed with refrigerant will not contribute to the cooling process, yet it takes up space and adds to the total pressure reading. Therefore, when diagnosing issues in a system, recognizing that trapped air can raise high-side pressures is crucial for proper evaluation and remedy of HVAC performance.

The other laws mentioned address different relationships or properties of gases. Gay-Lussac's Law relates pressure and temperature at constant volume, Charles' Law focuses on the relationship between volume and temperature at constant pressure, and Boyle's Law deals with pressure and volume at constant temperature. These do not directly address the implications of gas mixtures and pressure contribution as Dalton's Law does, which is why it is more applicable in this scenario.