Subcooling. How far the liquid leaving a condenser is below its saturation temperature — the bubble temperature on a blend — and worth about a percent of capacity per two to three kelvin. The refrigerant charts carry the bubble line.
Subcooling is how far the liquid leaving a condenser is below its saturation temperature at the condensing pressure. It guarantees solid liquid at the expansion device — flash gas in the liquid line starves a valve and shows as hunting — and it adds refrigerating effect: every kelvin of subcooling is a kelvin of liquid the evaporator no longer has to flash off, worth roughly a percent of capacity per two to three kelvin. Compressor maps are published at a stated subcooling — 8.3 K under AHRI 540, none under EN 12900 — and a map rated at 8.3 K read at zero over-states capacity by about eight percent on R410A, which is why this solver corrects every map to the operating subcooling.
On a zeotropic blend the measurement point matters. The liquid leaves the condenser at the bubble temperature, which on R448A or R455A sits 4 to 13 K under the dew temperature at the same pressure; subcooling is measured down from the bubble line, and a selection program that states 'liquid temperature' beside a dew-point condition is saying exactly that. Reading it from the dew temperature credits the liquid with heat it never had — seven percent of R455A's effect — and this solver measures from the bubble point on every fluid, which is the identity on a pure one. The bubble line is on every blend's pressure–temperature chart here.
Open the builder — the examples in the Design tab's sources list include a machine of this kind, and the Simulate tab runs it against a year of weather.
DOAS — dedicated outside-air system · SZVAV — single-zone variable air volume · VAV terminal box · Economiser · Waterside economiser · Demand-controlled ventilation · Face-and-bypass · Head-pressure control · Humidity ceiling and floor · Cycling and modulation · Coupling · Priority · Category · Nested system · Design point and TMY year · Superheat · Sensible heat ratio (SHR) · Bypass factor · Wet-bulb temperature · Dew point · COP and EER · Compressor map · Evaporating and condensing temperature · Range and approach · Heat-recovery (three-pipe) VRF · Typical meteorological year (TMY)