What are typical operating pressures for an R-410A system on the high side and low side under typical ambient conditions?

What are typical operating pressures for an R-410A system on the high side and low side under typical ambient conditions?

• A. High side 150–170 psi; low side 350–400 psi
• B. High side 250–300 psi; low side 90–110 psi
• C. High side 350–400+ psi; low side 150–170 psi
• D. High side 500–600 psi; low side 300–350 psi

Answer: (C)

R-410A systems run at higher pressures than older refrigerants, and the pressures on each side reflect the temperatures at which the refrigerant is condensing and evaporating. Under typical outdoor conditions with normal airflow and load, the high side (condensing) pressure is around 350–400+ psi, while the low side (suction) pressure sits around 150–170 psi. These values come from the need to condense the refrigerant at the ambient temperature and to evaporate it at the indoor coil temperature. If you saw readings as low as 150–170 psi on the high side, or 90–110 psi on the low side, that would suggest something unusual is affecting the system (like undercharge or a restriction). Very high readings, such as 500–600 psi on the high side or 300–350 psi on the low side, also indicate abnormal conditions or extreme ambient temperatures.

R-410A systems run at higher pressures than older refrigerants, and the pressures on each side reflect the temperatures at which the refrigerant is condensing and evaporating. Under typical outdoor conditions with normal airflow and load, the high side (condensing) pressure is around 350–400+ psi, while the low side (suction) pressure sits around 150–170 psi. These values come from the need to condense the refrigerant at the ambient temperature and to evaporate it at the indoor coil temperature.

If you saw readings as low as 150–170 psi on the high side, or 90–110 psi on the low side, that would suggest something unusual is affecting the system (like undercharge or a restriction). Very high readings, such as 500–600 psi on the high side or 300–350 psi on the low side, also indicate abnormal conditions or extreme ambient temperatures.