The hot vapour in the condenser must be warmer than the outside air to be able to give its heat to it. In an air-cooled condenser the condensing temperature is ambient temperature + 10–15 K: 45 °C at 32 °C ambient, 52–55 °C at 40 °C. The discharge pressure is the saturation pressure of this temperature: for R404A about 19 bar g at 45 °C.
Condensing temperature is the "most expensive" variable of the system: every 1 K rise increases compressor consumption by 2–3% and reduces capacity. A dirty condenser, a failed fan, a location without shade or air flow, an undersized condenser, air in the system (non-condensable gas) and overcharge all raise the condensing temperature; this is why the high-pressure switch shuts the system down.
The reverse is also true: "floating head pressure" control (fan speed control + electronic expansion valve) that lets condensing fall to 20 °C when the winter ambient is 5 °C reduces annual consumption by 10–20%; in systems with a mechanical valve, however, condensing must be held at a minimum of 25–30 °C, otherwise the valve cannot pass enough refrigerant. In our condenser catalog capacities are given by the condensing–ambient temperature difference.