If an R-410A heat pump has a suction pressure of 131 PSIG and you add 2 PSIG for pressure drop, what is the true outlet pressure?

To determine the true outlet pressure of the R-410A heat pump, one must consider both the suction pressure and any adjustments made for pressure drops in the system. The given suction pressure of 131 PSIG needs to be adjusted for the pressure drop of 2 PSIG. When you add 2 PSIG to the initial suction pressure, the calculation would yield 133 PSIG.

However, it is important to note that when calculating true outlet pressure, the pressure drop is typically subtracted from the suction pressure in most operational contexts to account for losses. Thus, the original suction pressure of 131 PSIG must be adjusted to reflect these losses correctly, resulting in the pressure reading remaining at 131 PSIG without any increase.

The misconception arises in directly adding the pressure drop instead of maintaining the baseline suction pressure. Therefore, the outlet pressure remains 131 PSIG because any losses are factored into the measurement, and pressure drop doesn’t necessarily result in a higher outlet pressure. This leads to the correct understanding that the outlet pressure, unaffected by the added adjustment, maintains the original suction pressure value.