Dampers aren't operating properly in Lynn's HVAC system. The repairwoman checks the pneumatic pressure and reads that it's 20 psi. This indicates that the psi is A) at risk for critical system failure. B) higher than operating tolerances. C) within operating tolerances. D) lower than operating tolerances.

To determine the correct answer regarding the pneumatic pressure reading of 20 psi in Lynn's HVAC system, we need to consider the typical operating tolerances for pneumatic systems. 1. **Understanding Operating Tolerances**: - Most HVAC systems have specific pressure ranges that are considered normal or acceptable for optimal performance. - If the pressure is too low, it may not be able to operate effectively, while too high a pressure can lead to system damage or failure. 2. **Analyzing the Options**: - **A) at risk for critical system failure**: This would imply that 20 psi is dangerously low or high, but we need to know the normal range to assess this. - **B) higher than operating tolerances**: This would mean that 20 psi exceeds the maximum acceptable pressure. - **C) within operating tolerances**: This suggests that 20 psi is an acceptable pressure for the system. - **D) lower than operating tolerances**: This would indicate that 20 psi is below the minimum acceptable pressure. 3. **Conclusion**: - Without specific information about the normal operating range for Lynn's HVAC system, we can make a general assumption. Typically, many HVAC systems operate within a range of about 15 to 25 psi. - If 20 psi falls within this range, then it would be considered "within operating tolerances." Based on this analysis, the most likely answer is: **C) within operating tolerances.**